How to calculate kim material utilization rate. Determination of the metal utilization factor. See what the "material utilization rate" is in other dictionaries
Basic concepts:material resources; basic and auxiliary materials; raw materials, materials, fuel and energy resources; consumption rate; general need for materials; material return; material consumption; material utilization rate; savings in material costs
1. Material resources of the organization: concept, composition, structure.
2. Planning and regulation of the consumption of material resources.
3. Evaluation of the efficiency of the use of material resources.
4. Factors and directions of increasing the efficiency of the use of material resources in the organization.
1. Material resources of the organization:
concept, composition, structure
Material resources represent part of the working capital of the organization, i.e. those means of production that are completely consumed in each production cycle, wholly transfer their value to the finished product and change or lose their consumer properties in the production process.
Under material resources refers to the objects of labor consumed in the production process in the form of raw materials, materials, purchased products, semi-finished products, fuel, energy.
In the food and light industries, for example, the cost of raw materials and materials exceeds 80% of the cost of production. On the scale of modern industry, a 1% reduction in material costs provides multi-billion dollar savings, which means a corresponding increase in profits and incomes.
As a rule, raw materials include products of the extractive industry (oil, ore, sand) and agriculture (crop products, animal husbandry).
Materials as products of labor that have undergone preliminary processing are products of the manufacturing or processing industry (ferrous and non-ferrous metals, building materials, flour).
According to the branch of origin, raw materials are divided into industrial and agricultural.
In turn, industrial raw materials are divided into:
-mineral;
– artificial (plastic, fabrics, etc.);
– secondary (waste and rejects of the main production, scrap metal, etc.).
Agricultural raw materials are represented by raw materials of plant and animal origin.
According to the degree of participation in the manufacture of products, raw materials and materials are divided into basic and auxiliary.
TO basic raw materials include those types of raw materials and materials from which the company's products are made or which are its integral part. The largest share of the material resources of the enterprise is made up of basic materials, which in their natural form are part of the finished product, constituting its material basis.
TO auxiliary materials include materials consumed in the process of servicing production or added to basic materials (lubricants, packaging materials, dyes, etc.).
In economics, the following types of auxiliary materials are distinguished:
1) joining the product, but not changing its consumer purpose (paints and varnishes, labels);
2) participating in the production process as a necessary element, but not joining the finished product (filters, catalysts, etc.);
3) ensuring the work of means of labor (lubricants, etc.);
4) fuel.
According to the stage of use, primary and secondary raw materials and materials are distinguished.
Feedstock and primary materials are the material resources initially used to create a product.
secondary raw materials in relation to a specific product, it is a raw material that is re-involved in the production process.
Source materials can be divided into 2 groups:
1) semi-finished products (intermediate products manufactured at previous stages of the production process);
2) primary materials coming from outside.
According to the structure of a typical chart of accounts, there are:
– raw materials and materials;
– purchased semi-finished products and components;
– structures and details;
- fuel;
- packaging and packaging materials;
- spare parts;
- Other materials;
- materials transferred for processing to the side;
- Construction Materials;
- inventory and household supplies;
– special equipment and special clothing in stock;
– special equipment and special clothing in operation.
All material resources used in industry as objects of labor are conditionally divided into raw materials and fuel and energy resources. The predominant part of the main materials in the manufacture of the product is called raw materials.
Fuel and energy resources by their economic nature, they belong to auxiliary materials, but due to their special importance for the economy, they are separated into an independent group.
According to the nature of their origin, fuel and energy resources are usually divided into:
1) natural (natural gas, coal, nuclear energy);
2) secondary (exhaust gas, fuel waste).
Electrical and thermal energy is consumed:
– for the main technological purposes;
– setting in motion tools and equipment;
– household needs (lighting, ventilation).
Structure of material resources- this is the ratio of certain types of raw materials and materials in the aggregate of material resources, measured as the share of a certain group of raw materials or materials in the total amount of material resources.
A necessary condition for the efficient production of products, reducing their cost, increasing profits and profitability is the complete and timely provision of the enterprise with raw materials and materials of the required range and quality. The growth of the enterprise's need for material resources can be satisfied in an extensive way (purchasing or manufacturing more materials) or intensive (more economical use of available stocks in the production process).
2. Planning and rationing of consumption
material resources
Planning and rationing of material resources is reduced mainly to the organization of their savings in the enterprise. Saving resources is the amount of raw materials and materials released through their efficient and rational use, the introduction of scientific and technological progress and advanced methods of organizing production and labor.
Actual and planned savings can be calculated both per unit of output and for the entire output. Actual savings are the result of a comparison of actual reported data, and planned savings are standard data.
Long-term efficient use of material resources and energy resources requires the organization of saving raw materials, materials, energy resources. In organizing and planning the use of material resources, the establishment of progressive norms for materials and fuel occupies the most important place.
The standard consumption of material resources per unit of output or type of work is called consumption rates.
Consumption rate- these are the values established by the plan that determine the maximum allowable costs of the relevant material resources for the production of a unit of a particular type of product.
The level of progressive norms should be above the achieved averages. The norms should guide workers towards the planned introduction of new technology, reflect advanced production experience, and change as technology improves, production is organized, and the qualifications of personnel grow.
The most progressive method of managing the technical and economic norms of material and fuel consumption is calculation and analytical method.
The essence of the method is that the consumption rate of materials consists of 3 parts:
1) useful content of materials in finished products (net weight) - FM;
2) waste received during the production process (mass of waste) - M o;
3) losses associated with the storage and transportation of materials (mass of losses) - M p.
The specific gravity of each part characterizes the structure of the norm.
The consumption rate (N p) of materials is calculated by the formulas:
H p \u003d FM + M o + M p
Total requirement for basic materials(OM) is determined by the formula:
OM \u003d H p × VP,
where VP is the volume of output of the product in physical terms.
The need of the enterprise for materials of the i-th type (M total) is determined taking into account the following constituent elements:
Mo bshch i \u003d M p i + M nt i + M p i + NP kg i + Z to i - NP ng i - Z n i + M in i,
where M p i - the need for materials for production needs; M nt i - the need for materials for the introduction of new technology; M p i - the need for materials for repair and maintenance needs; NK kg i , NP ng i - work in progress at the end and beginning of the year; З н i , З to i - production stocks at the end and beginning of the year; M in i - internal reserves.
3. Evaluation of the effectiveness of use
material resources
To assess the efficiency of the use of material resources, a system of generalizing and partial indicators is used.
General indicators include:
- material consumption of products (Me);
– material return of products (Mo);
is the ratio of the growth rates of production volume and material costs;
- coefficient of material costs.
The most common indicators characterizing the use of all material resources in an organization are the material consumption of products and the inverse indicator - material efficiency.
Material consumption and material return are determined by the formulas:
where MZ - material costs, p.; TP (RP) - marketable (sold) products, r.
Material productivity characterizes the return on the use of materials, that is, how much product is produced from each ruble of consumed material resources (raw materials, materials, fuel, energy, etc.).
Material intensity shows how many material costs actually fall on the production of a unit of output.
The ratio of the growth rate of production volume and material costs is determined by the ratio of the gross output index to the index of material costs.
Coefficient of material costs (K mz) represents the ratio of the actual amount of material costs to the planned, recalculated for the actual volume of output.
If K mz is greater than one, then this indicates an overspending of material resources.
If Kmz is less than one, then this indicates that material resources were used more economically.
TO private indicators of material consumption of products include metal content (E met), electrical capacity (E el) and energy intensity (E en), calculated by the formulas:
where N met - the amount of metal consumed; N el - the amount of electricity consumed; N en - the amount of energy consumed of all types, tons of standard fuel; TP (RP) - the volume of marketable (sold) products, p.
Particular indicators include the level of material consumption of individual products - the ratio of the cost of all consumed materials to the cost of production.
No less significant for the analysis and justification of reserves are utilization factors, which characterize the degree of use of raw materials and materials.
Material utilization rate(To isp.m) is determined by the formula:
There are two options for calculating the utilization rate:
1) regulatory;
2) actual.
Normative utilization factor calculated as the ratio of useful consumption (net weight) to the consumption rate.
Actual utilization rate calculated as the ratio of useful consumption to the actual consumption of this product.
The reciprocals of utilization rates are called expense ratios.
Product yield(semi-finished product) expresses the ratio of the amount of product produced (semi-finished product) to the amount of raw materials actually consumed, (for example, the yield of fabric from yarn, lumber from industrial wood, sugar from sugar beets, etc.).
The degree of use of the useful substance contained in the feedstock in the appropriate form characterizes coefficient of extraction of the product from the feedstock. This indicator is determined by the ratio of the amount of useful substance extracted from the feedstock to its total amount contained in this raw material.
Relative savings or cost overruns of materials(E m) is determined by the formula:
where R f is the actual consumption of materials; R p is the planned consumption of materials; V p is the production plan; V f is the actual output.
Relative savings in material costs(E m) is determined by the formula:
E m \u003d M b × K - M p,
where E m - relative savings in material costs; M b, M p - material costs for the social product in the base and planned years; K is the index of growth in the volume of production of the social product in the planned year compared to the base year.
4. Factors and directions for improving efficiency
use of material resources in the organization
Groups factors determining material savings:
1. Material, which involve the choice of optimal types of materials that help reduce their consumption, reduce the consumption of especially scarce materials and reduce the amount of material costs in the cost of production. Material factors also include the preparation of materials (enrichment, etc.).
2. Technological, including the choice of such options for technological processes that reduce the waste generated in the production process. These include precision casting methods, stamping, welding, improved cutting of materials, etc.
3. Design and construction, which lead to material savings through the selection of optimal designs (designs) of finished products, the elimination of excessive safety margins and excesses in products.
4. Organizational and economic, consisting in the rational use of waste, reducing the loss of materials during storage and transportation.
Directions for increasing the efficiency of the use of material resources in the organization:
- integrated use of raw materials, materials and fuel and energy resources;
– high-quality preparation of raw materials and materials for production, the introduction of their effective substitutes;
– improvement of the regulatory framework;
– the introduction of progressive, primarily low-waste and waste-free, production technologies;
– strict observance of technological processes and maintenance of the technical park of the enterprise in working order;
– improvement of product quality;
- the use of production waste as a secondary raw material;
- management of working capital in the organization in order to minimize them, etc.
Reducing the material consumption of products allows you to:
- reduce production costs;
– increase competitiveness;
- increase profits;
- accumulate own financial resources sufficient for expanded reproduction, introduction of innovations, and increase the output of products from the same amount of material resources;
- reduce the standard amount of working capital required by the organization for normal functioning;
- improve the financial condition of the organization and reduce the risk of bankruptcy.
Similar information.
The main goal of any commercial institution is profit maximization. This means the need to cut costs. The coefficient of use of materials is an indicator that allows you to evaluate the rationality of the latter, their need to obtain the final result. If a firm wastes too many resources, then it cannot be successful. is possible in a competitive environment only by minimizing costs.
Manufacturing as a process
The definition of materials allows you to evaluate whether the output of products is efficient and rational. Then, if the indicator does not satisfy us, we must try to change the situation. However, this is completely impossible if you do not have an idea about the production process. Therefore, to begin with, let's consider it using the example of the engineering industry. It is convenient for analysis, since most enterprises in this area are similar.
At the first stage, the creation of blanks from raw materials and materials takes place. Already here we can face costs. The more raw materials are wasted, the more the material utilization factor will deviate from unity. The second stage is associated with the processing of blanks and giving them the required configuration. Naturally, this also comes with costs. Moreover, they depend on the effectiveness of the initial stage. At the third stage, the preliminary and direct assembly of products takes place.
Indicators of production factors
Manufactured products can be characterized both in physical units and in value terms. Everyone understands that a firm can continue to operate when its income exceeds its costs. However, what are the latter? Consider a three-factor model. In order to produce products, we need tools. These are our main funds. The rationality and efficiency of production depends on how we use them: intensively or extensively. Characterizes the effectiveness of these factors capital productivity. The inverse of this indicator is also used.
Also, for the production of goods, objects of labor are needed. These are ours. That's just them and characterizes the coefficient of use of materials. Efficiency is indicated by the indicator already mentioned in the description of fixed assets. This is material yield. Finally, important is It can also be used extensively and intensively. And it affects our costs. labor force is the productivity of personnel and the labor intensity of products. These are also reverses.
Material utilization rate
The formula of this indicator characterizes the working capital factor. Also, the use of objects of labor reflects the output of finished products. The latter indicator, as a rule, is used in industries where primary processing of raw materials takes place.
In the manufacturing industry, the utilization rate of materials is more often calculated. They reflect what percentage of raw materials should have been contained in the finished product, and how everything looks in reality. There are two types of utilization rates.
Planned
The first type of indicator, as the name implies, is predictive. It is used in planning further activities and building a development strategy. The formula is as follows: Kpl \u003d Mch / Mn. It uses the following conventions: Kpl is the planned utilization factor, Mch is the net weight of the product, Mn is the consumption of materials according to established standards. As can be seen from the formula, it poorly reflects the real situation. The norm is set for a hypothetical situation. In fact, we may face much greater than planned costs.
Actual
This indicator already more realistically characterizes the use of objects of labor. We introduce conditional notation. Let Kf be the actual utilization factor, Mch be the net weight of the product, as in the previous case, and Mf be the material actually used. Then the formula will look like this: Kf \u003d Mch / Mf.
It is easy to see that in both cases the coefficient can take values from 0 to 1. However, in reality it cannot be equal to one. Always some part of the material is wasted, but not contained in the finished product. But it is important to understand that part of it can be reused or recycled, which the coefficient in question does not take into account. Therefore, the production process should always be analyzed comprehensively, and not just focus on numbers.
Material consumption rate
This is another important indicator that characterizes the conditions in the industry. We introduce conditional notation. Let C be the material consumption rate, and Kf the number of units of actually produced products. For the formula, we also need the actual material utilization factor - Mt. Let Ned be the rate of consumption per unit of output. Then C \u003d (Mf / Kf * Ned) * 100%.
Efficiency improvement factors
The rational use of materials allows the company to maximize profits. However, much depends on the situation in the industry as a whole.
The following factors influence the rate of consumption of materials:
- Improving the technology of the production process. If the enterprise and the industry develop, then over time, less and less defects per unit of output are obtained. And this means that the material begins to be used more rationally, and costs are reduced.
- Improving the technical preparation of the production process. Here we are talking about improving the design of parts, the choice of workpieces and materials.
- Improving the organization of the production process. This can include the development of cooperation between departments, the deepening of specialization, and the improvement of planning processes.
Example
Consider cutting chipboard for the manufacture of parts. The more rational it is, the less material we waste. The utilization factor in this case will be equal to the ratio of the areas of the stamped part and the workpiece. The better the cutting of chipboard, the closer this indicator is to one. But what should it be?
We cannot change the area of the stamped part in any way. Its dimensions are clearly defined. However, we can influence the area of the workpiece. It is determined by multiplying the step between the parts by the length of the strip. The more economically the contours of future blanks are located, the smaller the gaps between them. This means less material consumption. Thus, from the same amount of raw materials, the company will be able to make more products. Costs will decrease and profits will increase.
RAW MATERIAL USEFUL COEFFICIENT - the ratio of the mass of the finished product (raw materials that have passed into the product) to the mass of the feedstock is calculated as a whole for the raw material and for its individual components.
Comparing data on the acquisition of raw materials and materials with their quantity in the final product, the computer determines the efficiency of raw materials and materials. When comparing this coefficient with the normative or calculated one, the auditors conclude that the use of material resources in the enterprise is rational. If these coefficients coincide or are as close as possible to each other, then the head of the audit team decides that it is not advisable to audit this section according to primary documents. If the coefficient of actual use of raw materials and materials is significantly lower than the standard or expected, it is necessary to conduct an in-depth audit of the use of those types of raw materials and materials for which discrepancies were identified.
RAW MATERIAL USEFUL COEFFICIENT -
Efficiency of raw materials 85
The reduction in material consumption also depends on an increase in the level of design developments, including a reduction in the net weight of products, an improvement in production technology and an increase in the quality of raw materials and materials. The impact of the last two factors on reducing the material consumption of products to a certain extent characterizes the indicator of the share of waste in the total cost of the materials used. For the same purpose, the coefficient of useful use of materials is used.
The plan should be aimed at an all-round increase in the efficiency of gas resources, at the elimination of losses of this highly valuable raw material for the chemical industry.
In the problem of the rational use of oil and gas, an increase in the coefficient of their useful use is of great importance. One of the main directions here involves deepening the level of oil refining in order to meet the country's demand for light oil products and petrochemical raw materials. links of the national economy.
The demand for gas is everywhere. world is currently exceeding its supply capacity, which confirms its high economic performance and advantages over other types of fuel and raw materials. Suffice it to say that the use of gas to generate electricity can reduce specific capital investments by 1.5-2 times, and the cost - by 2-3 times increases the productivity of industrial boilers by 30%, increases the efficiency of boilers by 1.2 times. The technical and economic indicators of gas turbine power plants are even higher. The effect of using natural gas in ferrous metallurgy is manifested in a reduction in the consumption of scarce coke by 10-15%, in an increase in the productivity of blast furnaces by 1.5 times. A great economic effect is achieved by using gas in the building materials industry, especially in the production of cement. The use of gas in the chemical industry releases a large amount of food products, reduces specific investment by 1.4-2.4 times, and the cost of production - by 1.1-2.0 times. Finally, the use of gas in everyday life provides for each average family an annual saving of 60-80 rubles. and reduces the time spent on farming. So natural gas will also improve the social and living conditions of the population.
COMBINATION IN THE INDUSTRY - the combination at one enterprise of several related industries. There are vertical combination - combining by a sequence of stages of processing of raw materials and horizontal, associated with the complex use of raw materials containing various useful components, or playing an auxiliary role in relation to the main production. An indicator of the level of combination of production of a particular product can be the share of the product that has undergone processing within the enterprise in the total volume of its production. A generalizing indicator of the level of combination in the production of heterogeneous products is the coefficient of production combination - the ratio of the value of the gross turnover of an industrial enterprise to the value of gross output.
INDICATORS OF THE USE OF RAW AND MATERIALS - indicators characterizing the level of their use in production. The main ones (planned and actual) are the utilization and cutting factors, the consumption coefficient of the output of products (semi-finished product), the coefficient of extraction of the product from the feedstock. Utilization coefficient - the ratio of the useful consumption of material, etc. to the consumption rate, established for the production of a unit of output (work, services). For example, the weight of the part is 12 kg, the metal consumption rate is 16 kg, the utilization factor will be 0.75 (12/16), so 25% of the metal goes to waste. Consumption coefficient - the ratio of the consumption rate of materials (raw materials), established for the production of a unit of output (work, services), to their useful consumption, an indicator that is inverse to the utilization factor. Cutting coefficient - the ratio of the mass (volume, area, length) of all types of blanks obtained from the source material to the mass (volume, area, length) used. For example, from 5 m2 of raw materials, 4 m2 of finished products were obtained, the cutting ratio is 0.8 (4/5), thus, the degree of use of the material during its cutting is 80%. The output of the product (semi-finished product) is the ratio of the amount of the produced product (semi-finished product) to the amount of the actually consumed source
With intensive reproduction, economic growth is achieved through the qualitative improvement of production factors. comes down to saving time, reducing costs per unit of useful effect. Intensive economic growth can be carried out on the existing technological basis by making the most complete use of working time, increasing the shift ratio, using secondary raw materials and saving resources. However, in its proper sense, intensive economic growth always implies scientific and technological progress and a change in production technology. This is manifested in an increase in the final results of production, resource saving and the release of labor.
The use of new machine systems, new equipment encourages the improvement of production technology, the introduction of its progressive types, such as centrifugal casting, injection molding, electro-hydraulic stamping, powder metallurgy, laser and electron beams, etc. The introduction of the technology of complex processing of raw materials is especially promising. and resource - saving technology . Extraction of by-products during the production of the main product during the processing of ores, the integrated use of wood significantly increase their efficiency. Waste is reused. gases and steam, the need for fuel is reduced at enterprises, natural gas, which is a source of chemical raw materials, coal is saved, and the need for wagons necessary for its transportation is reduced.
There are opportunities for further improvement of the technological process, including by improving the catalyst, continuously feeding it with phosphoric acid, minimizing the loss of sulfuric acid, increasing the useful chemical utilization of hydrocarbons, etc.
In the process of analysis, the coefficient of use of raw materials, materials is calculated, which is the ratio of the weight of the finished product to the weight of the workpiece. This coefficient reflects the degree of useful use of the material.
C - the degree of conversion (transformation) of raw materials, in shares. units X - coefficient of use of the useful volume of the device, in
However, the most important factor influencing labor productivity, capital productivity, use of production capacity, cost, profitability and, as a result, profit, in this case, is the quality of the processed raw materials. The fact is that the content of useful substances in sugar beets, potatoes, tomatoes, grain crops varies from year to year depending on climatic, agrotechnical and other factors. Suffice it to say that an increase in dry matter in tomatoes by 1% is equivalent to an increase in raw materials by 18-20%, an increase in the sugar content of beets by 1% would make it possible to additionally obtain 10 kg of sugar, and from each ton of potatoes - 6-8 kg of dry starch, etc. P. Therefore, in seasonal production, the indicator of the output of products from 1 ton of raw materials (or useful substances from raw materials) is used - the coefficient of extraction of useful substances from raw materials. The power of such enterprises is
Scientific and technological progress has a great influence on the involvement of natural resources in the production process. On the one hand, it contributes to the rationalization of the use of natural resources, the identification of cheaper and easier to transport fuel resources (natural gas through pipelines), the introduction of a more complete extraction and processing of oil (currently, the average reservoir recovery factor for fuel resources is about 45%, including 80-90% for open-pit coal, 35-80% for mine production, 35% for oil, 80% for natural gas)
The coefficient of extraction of the product from the feedstock characterizes the degree of use of the useful substance contained in the corresponding type of feedstock. It is determined by the ratio of the amount of useful substance extracted from the feedstock to its total amount contained in this raw material.
The performance of the equipment largely depends on the quality of raw materials and raw materials. For example, in ferrous metallurgy, improving the quality of coke and iron ore improves the utilization of the useful volume of blast furnaces.
The wide use of plastics makes it possible to carry out technical. progress in many branches of industry, technology and steam. x-on the whole. For example, the creation of radar equipment would be practically impossible without the use of such dielectrics as polyethylene, reinforced plastics on polyester binders, etc. Thanks to the use of plastics, it was possible to create printed circuits in radio electronics, ablative thermal protection of space. ships, electrically insulating, antifriction materials, structures that ensure the transition to industrial methods in construction, and to widely introduce such a method of precision metal casting as casting into shell molds, etc. A number of factors determine the rapid development of P. m. given properties through combination and modification of plastics, as well as through the implementation of controlled polymerization and zero-condensation (obtaining stereoregular polymers with improved physical, mechanical, thermal and other properties) availability of practically unlimited resources of cheap raw materials release of scarce raw materials and materials good performance properties plastics the possibility of processing plastics into products by highly efficient, economical methods, while the efficiency of plastics is 0.9-0.95 versus 0.6-0.7 for metals.
Indicators of the use of working capital in the enterprise. The following indicators can be used to analyze and plan the consumption of material resources: utilization factor, cutting factor, product (semi-finished product) yield, product extraction factor from the feedstock.
Utilization factor characterizes the degree of use of raw materials and materials and is determined by the ratio of useful consumption (mass, theoretical consumption) to the consumption rate of materials established for the manufacture of a unit of output (work).
cutting factor- an indicator characterizing the degree of useful use of sheet, strip, roll materials, mainly in procurement production; is determined by the ratio of the mass (area, length, volume) of production blanks to the mass (area, length, volume) of the original workpiece of the material being cut.
Consumption ratio- an indicator that is inverse to the utilization factor and cutting factor. It is defined as the ratio of the rate of consumption of material resources established for the production of a unit of output (work) to their useful consumption.
Product output (semi-finished product) expresses the ratio of the amount of the produced product (semi-finished product) to the amount of actually consumed raw materials. For example, the output of fabric from yarn, sugar from sugar beet, vegetable oil from oilseeds, lumber from wood, etc.
Product recovery factor from feedstock characterizes the degree of use of the useful substance contained in the corresponding type of feedstock. It is determined by the ratio of the amount of useful substance extracted from the feedstock to its total amount contained in this raw material.
The most important generalizing indicator of the level of use of all material resources in the enterprise is material consumption of products; inverse indicator of material consumption of products - material return.
Material consumption (M e) and material output of products (Mo) are determined by the formulas
where MZ is the amount of material resources expended at the enterprise;
TP - release of marketable products at the enterprise;
Vp is the volume of products sold.
Particular indicators of the material consumption of products include metal consumption, electrical intensity and energy intensity.
The index of metal consumption of products (M met) is determined by the formula
electric capacity (Mzd):
energy intensity (Mdd):
All these private indicators can be defined both in kind and in value terms.
For any enterprise, especially for machine-building, it is very important to know how efficiently metal is used. For this purpose, such indicators of the level of metal use as the coefficient of relative metal consumption, the coefficient of metal utilization and the integral coefficient of metal utilization are used.
Relative metal consumption coefficient(K o.m) characterizes the level of metal use at the design and construction stage of machines and equipment and shows how perfect this or that design is from the rational use of metal, is determined by the formula
The parameter can be, for example, tractor power in horsepower, engine power in kW, vehicle load capacity in tons, etc.
Metal utilization rate(K.m) is determined by the formula
It characterizes the level of use of metal at the stage of manufacturing machines, equipment or structures.
For a generalized characteristic of the use of metal, both at the stage of design and construction of machines and equipment, and at the stage of their manufacture, the integral coefficient of metal utilization (Kgm) is used, which is determined by the formula
The smaller the value of this indicator, the more perfect the design and the better the metal is used in the manufacture of products at the enterprise.
Example
At the tractor plant, tractors with a capacity of 200 hp were produced, and their net weight was 4.5 tons. The rough weight of metal for the manufacture of one tractor was 6.0 tons.
After improving the design of the tractor and introducing new equipment into production, its power increased to 250 hp. while maintaining the same net weight, and the rough metal consumption per tractor was 5 tons.
Determine the metal utilization rates before and after the design improvement and the introduction of new technology.
Solution
1. We determine the indicators of the use of metal before improving the design of the tractor and introducing new equipment:
2. We determine the indicators of the use of metal after improving the design of the tractor and introducing new equipment:
Thus, the total metal savings per 1 hp. was 9.3 kg (29.3-20).
Indicators of the use of material resources are very diverse and depend on the specifics and profile of the enterprise. For example, in the iron ore industry, the main indicators characterizing the use of extracted raw ore are: metal content in concentrate, concentrate yield, extraction of iron into concentrate, and iron content in tailings. These indicators characterize the beneficiation process from the point of view of rational use of raw ore.
The output of concentrate from iron ore (υ) is determined by the formula
where α, β, θ - respectively, the iron content in the original ore, concentrate and tailings, %;
Qk , Qp - respectively, the mass of the obtained concentrate and the raw ore consumed to obtain the concentrate, i.e.
The degree of extraction of iron in the concentrate reflects the completeness of the extraction of the useful component of natural resources and partly characterizes the efficiency of the enrichment process. It is defined as the ratio of the mass of metal in the concentrate to the mass of metal in the original ore:
It should be noted that for each mining enterprise, all these indicators should have optimal values, calculated taking into account the costs of extraction, enrichment and transportation, as well as the costs of metallurgical processing. Defined in this way, they will also reflect the minimum material costs.
At the enterprises of the chemical industry, the indicator of the use of materials (Km) is determined by the formula
where Rt.m is the theoretical consumption of materials (established in accordance with the approved technology or recipe);
Rf.m - the actual consumption of materials (usually exceeds the theoretical consumption by the amount of losses that occur during a chemical reaction).
An important indicator that characterizes the level of use of material resources in any enterprise is the specific consumption of any material resource per unit of output in physical terms.
An analysis of this indicator in dynamics makes it possible to judge whether the enterprise has a policy in the field of resource conservation, whether it is being successfully solved.
If in dynamics the actual consumption of material resources per unit of output (work) tends to decrease, then the company implements a policy for the rational use of material resources.
When designing a blank, for each variant of its manufacture, three material utilization factors are calculated, taking into account its losses:
Throughout the process
In the preparation shop
(6)
In the machine shop
(7)
Where M det., M ref., M zag.- the mass of the part, the original workpiece (ingot, blank, rod, pipe, etc.) and the workpiece (casting), respectively.
When choosing a method for obtaining a workpiece, the most important indicator for this production is taken into account.
The final choice of the method for obtaining the workpiece
At the lowest cost or (if it is equal in the two options under consideration) at the maximum utilization rate of the material, finally select the method for obtaining the workpiece. In the first case, it is necessary to calculate the annual economic effect, in rubles, from the introduction of a rational method for obtaining a workpiece according to the formulas:
with a constant technological process of machining, and in the general case
Where S zag.2, S det.2- the cost of manufacturing the workpiece and part according to the selected option;
S zag.1, S det.1- the cost of procurement of an alternative;
N- the annual program for the production of products, pieces / year.
7. Security questions
1. Give a diagram of the foundry; describe the essence of the process. Explain the importance of foundry in mechanical engineering. What is the economics of this process?
2. Describe the main casting properties of alloys and ways to obtain castings without defects.
3. How is the quality assessed for different purpose groups of castings?
4. What factors influence the choice of the method for obtaining a billet by casting? Give examples.
5. Describe the methods for obtaining blanks by casting; give their technical characteristics; indicate the scope.
6. Describe the technology for making sand castings. Varieties, advantages, disadvantages and scope of this method. Explain your answer with diagrams.
7. Describe the technology for manufacturing castings in metal molds (chill molds). Varieties, advantages, disadvantages and scope of this method. Explain your answer with diagrams.
8. Describe the technology of casting into shell molds. Varieties, advantages, disadvantages and scope of this method. Explain your answer with diagrams.
9. Describe the technology of casting by investment casting. Varieties, advantages, disadvantages and scope of this method. Explain your answer with diagrams.
10. Describe the manufacturing technology of injection molding. Varieties, advantages, disadvantages and scope of this method. Explain your answer with diagrams.
11. Describe the technology for manufacturing castings by centrifugal casting. Varieties, advantages, disadvantages and scope of this method. Explain your answer with diagrams.
12. What are the goals of preliminary heat treatment of castings? List the types of heat treatment of castings used for various alloys, and indicate the results achieved.
13. List and explain what information is applied to the casting drawing by the product designer, technologist of the machine shop.
14. Specify the procedure for developing a casting drawing.
15. How does the technologist of the blank shop implement the requirements put forward by the designer of the part and the technologist of the mechanical shop when designing the drawing of the workpiece when designing the casting technology? Illustrate, explain.
16. What is an allowance for machining? Why is it appointed, how is it determined? Illustrate.
17. What is a lap? Why is he appointed? Illustrate.
18. What factors affect the casting accuracy? What errors are taken into account in casting tolerances? The rule for dividing the tolerance field into castings.
19. Specify and explain the technological requirements for the design of parts obtained by casting.
Bibliographic list
1. GOST 26645-85. Castings from metals and alloys. Dimensional tolerances, weights and machining allowances. - M.: publishing house of standards, 1989. - 54 p.
2. GOST 3.1125-88. Rules for the graphic execution of elements of casting molds and castings. - M.: publishing house of standards, 1988. - 19 p.
3. GOST 977-88. Steel castings. General specifications. - M.: publishing house of standards, 1989. - 56 p.
4. GOST 321.2-92. Model kits. Molding slopes, core marks, dimensional tolerances. - M.: publishing house of standards, 1992. - 20 p.
5. Reference technologist-machine builder /Comp. A.G. Kosilova, R.K. Meshcheryakov. - M .: Mashinostroenie, 1985. - T1. – 556 p.
6. Automation of the design of technological processes /Under the general. ed. I.L. Kapustin. – M.: Mashinostroenie, 1985. – 304 p.
7. Gorbatsevich A.F., Shkred V.A. Course design for engineering technology. - Minsk: Higher. school, 1983. - 255 p.
Initial data for an individual task (example)
Material Br OF10-1
General purpose casting
Production program N 10000 pcs/year
The parting plane of the mold is along the axis of symmetry of the casting
An example of a casting drawing
|
1. Casting accuracy 6-5-6-0 cm 0.44 GOST 26645-85
2. Weight 0.92-0.39-0.01-1.32 GOST 26645-85
3. Casting group I GOST 977-88
4. Casting difficulty group 2
5. Hardness HB 80
6. Unspecified casting radii 5 mm
7. Unspecified casting slopes 1°
8. The depth of occurrence of defects is not more than 0.5 h of the value of the allowance for processing
Annex 2
Table A.2.1 Characteristics of metals and alloys
| Material | Density, g / cm 3 | Melting point, 0 С |
| BECOME | ||
| 7,85 | Around 1500 | |
| 7,826 | -//- | |
| 7,021 | -//- | |
| 15L, 20L | 17,83 | -//- |
| 30L | 7,82 | -//- |
| 40L | 7,85 | -//- |
| 15HGS | 7,85 | -//- |
| 20X1ZL | 7,74 | -//- |
| Р9К10 | 8,1 | -//- |
| WX15 | 7,81 | -//- |
| Brass | 8,5 | Around 1080 |
| BRONZE | -//- | |
| 010F1 | 8,8 | -//- |
| 0Ф10-1 (in a chill mold) | 8,76 | -//- |
| 0Ф10-1 (to the ground) | 8,59 | -//- |
| ALUMINUM ALLOYS | ||
| Al 1 | 2,81 | About 600 |
| Al 4 | 2,65 | -//- |
| Al 5 | 2,7 | -//- |
| CAST IRON | ||
| Cast iron gray | 7,3 | Around 1100 |
| Ductile iron | 7,45 | -//- |
Table A.2.2 Indicative data for determining the serial production of castings
| Group of castings by weight | Casting weight, kg | Annual production of castings of the same name for various types of production, pcs | ||||
| single | small-scale | serial | large-scale | mass | ||
| (small) | <20 | <300 | 300–3000 | 3000–35000 | 35000–200000 | >200000 |
| 20–100 | <150 | 150–2000 | 2000–15000 | 15000–100000 | >100000 | |
| (medium) | 101–500 | <75 | 75–1000 | 1000–6000 | 6000–40000 | >40000 |
| 501–1000 | <50 | 50–600 | 600–3000 | 3000–20000 | >20000 | |
| (large) | 1001–5000 | <20 | 20–100 | 100–300 | 300–4000 | >4000 |
| (very large) | 5001–10000 | <10 | 10–50 | 50–150 | 150–1000 | >1000 |
| >10000 | <5 | 5–25 | 25–75 | >75 | - |
Table A.2.3 Classification of castings by purpose
Table A.2.4 Technical capabilities of casting methods
| Casting accuracy class (quality) | Roughness parameters according to GOST 2789-73 | Allowance, mm | Material utilization factor ( KIM) | Good casting yield, % | Problems |
| 6–14 (IT 14–19) | Rz40 (for non-ferrous alloys) Rz80 and coarser (others) | 2–14 | 0,71 | 30–50 | Low accuracy, high labor intensity |
| 4–11 (IT 13–18) | Rz20 (for non-ferrous alloys) Rz40 and coarser (others) | 1,5–8 | 0,74 | 410–50 | It is difficult to obtain thin-walled castings of complex configuration (especially from an alloy with high shrinkage) |
| 3–8 (IT 12–15) | 0,2–0,7 | 0,91 | High labor intensity, complexity of process automation, high cost of castings | ||
| 3–8 (IT 12–15) | Ra2.5 (for non-ferrous alloys) Rz20 and coarser (others) | 1–8 | 0,90 | 50–60 | High cost of synthetic resins |
| 3t–7 (IT 11–14) | Ra0.63 (for non-ferrous alloys) Ra1.25 and coarser (others) | 0,3–1,5 | 0,95 | Low resistance of molds in the production of castings from alloys with high melting point |
Table A.2.5 Application areas of the main casting methods
| Casting method | Received castings |
| in sand molds | Any configuration, size and weight |
| In metal molds (chill molds) | Simple and medium complexity, small and medium in weight and size in serial and mass production |
| Centrifugal | Small and medium-sized in serial and mass production, having the form of bodies of revolution |
| In shell molds | Small and medium, medium complexity with increased accuracy and surface finish in series and mass production |
| Lost Wax Models | Small ones of any complexity, with high dimensional accuracy and high surface finish, mainly from steel and hard-to-cut alloys in serial and mass production |
| Under pressure | Small any configuration, with high dimensional accuracy and high surface finish from zinc, aluminum and magnesium alloys in large-scale and mass production |
| Continuous | Long, round and rectangular in mass production |
Table A.2.6 Classification of castings by complexity
Appendix 3
values of the basic cost and correction factors of casting methods
