I want to hear from you. By using this method, the costs are assigned to the specific category of equipment being used. You can find the required information about the required time in the books and handbooks on heattreatment of metallic materials. He can be reached by phone at 520-825-7191 or e-mail at jdossett64@msn.com. heat treatment is the type, consistency and control of the furnace atmosphere. thc = Time in hours calculated to compensate for the heating or cooling portion of the heat treatment cycle.      As an example, energy costs were allocated by the square feet the heat treat occupied rather than using the fact that about 90% of the plant energy costs was used in the heat treat, even though it occupied only 5% of the area of the plant. 5-feet-high x 8-feet-long x 4-feet-wide aluminum treating furnace cost analysis, Table 2. Process-control costs include the outside purchases of replacement thermocouples, protection tubes, instrumentation checks, instrument replacements, periodic furnace surveys, and thermocouple and temperature calibration checks. if for lesser time then what is the relationship between Heattreatment time and sample size. 6. A “1” is used as the average. Heat Treating Controllers. The first half of my career as a metallurgist and heat-treat manager was spent in captive heat treating. Hollomon #1. These furnaces were used for hardening 17Cr and 27Cr white irons, solution treating manganese steel, and normalizing and annealing other steels.      The technique used here of balancing the total costs or use of a cost component needs to be appled for all of the basic components of cost to ensure that the included uses balance to the overall use. That usage was added to the pusher furnace because of the push frequency, resulting in greater oil carry out. Calculate oamount of carbide (Fe 3 C) present at 1338 F for SAE 1045.  Room temperature is a constant. Any steel alloy has high conductivity to heat capacity ratio, which means that even parts as thick as 50-60 mm will attain the furnace temperature in a matter of minutes. Allocation of Process Control and Quenchant Costs. Nitrogen, depending on its use for the process or as a safety purge, may need to be an allocated cost. The output was fed to a looped common header. These factors include energy unit conversions and liquid-to-gas conversions for various commodities used in the heat-treating processes. So, for plate 5 mm thick use 10-20 mins. But if you mean some sertain kind of heat treatment there are of course some ways to calculate the time needed. Chromium Nickel Steels Not Hardenable by Heat Treating . How can I calculate the time it takes for the metal to reach the target temperature? An advantage of the system would be that if the loading characteristics of individual parts and the process cycle are known, one could accurately determine the required price per piece or price per pound for that equipment and process. Ghulam Ishaq Khan Institute of Engineering Sciences and Technology. Ovako. In this experience, the company had pages and pages of prices by the pound for each of the many treatments that were offered. How we can decide the post heat treatment temperature range for any metal or for alloys. For temperiing it would be 2 Hr/Inch. Figure 8: Structure of calculations Upon entering the screen for the calculations, see figure 9, the user must first select the process of interest, the options being First, however, the allocated costs of process control and repairs/maintenance need to be determined (as follows) for the generator operation. The latter two numbers are multiplied to give the cost per hour for that commodity. PLz help me to understand what is Grain Size and Grain Number.      Some useful conversion factors for the necessary calculations are shown in Table 1. The two-zone batch atmosphere furnaces were kept in certification to AMS 2750 as well as two companion tempering furnaces. The depth of the surface decarburization layer exceeds the final processing allowance and the part is scrapped. The other unique features added to these spreadsheets are the line for efficiency factor (profit) contribution to selling price. Heat treatment of steels is the heating and cooling of metals to change their physical and mechanical properties, without letting it change its shape. Calculation: for heat on object. Most companies keep the cost of direct labor as a separate line item, and the average number of direct-labor employees (i.e. The total hourly cost is $6.70, or $2.23/1,000 cf. An additional cost component of production/on time was added for the pusher to allow for the longer start-up period that was required. the average hourly cost for direct labor) can easily be determined. 2.   Air and Natural Gas Flow Capacity Chart (SCFH), Hauck Manufacturing Co., Lebanon, PA, www.hauckburner.com. For more information:  Jon Dossett, is a metallurgical engineer with over 48 years in the field of heat treating. By closing this message or continuing to use our site, you agree to the use of cookies. Direct costs are those directly associated with the equipment or equipment grouping for which the costs per hour of operation are being determined. In case of steels the thumb rule for annaealing/ hardening would be 1 hr/ inch. is 900, if I want to know how much time it will take to reach 300 then how can we know that? These empirical soaking time and heating/cooling cycle are determined based on TTT and CCT curves for corresponding alloys and desired phase at the end of heat treatment cycle. used by an individual piece of equipment is available, that number is assigned and used. But if you mean some sertain kind of heat treatment there are of course some ways to calculate the time needed. Copyright ©2021. 2. The costs could then be accurately assigned to the hourly cost of operation for each piece of equipment or similar groups of equipment. The nitrogen flows for nitrogen purging were set at each furnace to be the same as the endothermic gas flows. I would like to know if there is any relationship between shear and tensile strength of metals, and can we relate them with von Mises theorem or not? International.      Sales and utilization data were recorded for similar classes of these furnaces. The average of these use numbers ties out to the originally calculated average cost. Dissertação apresentada para obtenção do grau de Doutor em Engenharia Metalúrgica, na Faculdade de Engenharia da Universidade do Porto, sob a orientação do Prof. Doutor Mário A. Barbosa. Two concentrations of temperature-controlled polymer quench (5% and 20%) were available for use in holding tanks at each unit. Can we calculate the quenching time theoretically and also can we calculate it using cfd?      In order to ensure that all applicable costs have been covered, a separate spreadsheet may be necessary – after the first draft of the cost sheets or after any significant changes in equipment – to look at the totals of the direct personnel assignments, utilities use, assignment of depreciation costs and the use of other commodities to make sure that the desired totals tie out. Ideally for austenitization , the holding time is decided based on sample size but is there a thumb rule ? Repairs/maintenance includes the cost of outside purchases of replacement materials and services used to maintain the equipment such as fans, motors, bearings, radiant tubes, refractory, hearths or skid rails, etc. Materials heat treated were steel, steel investment castings, aluminum castings, various cast irons, and wear- and corrosion-resistant cast iron. For example those proposed by Anil Kumar V. We use regimes defined by experience and it is 2-4 minutes for 1 mm of thickness. The spreadsheet is shown in Figure 4. The objective was the development of a simple, cost/pricing system that would be reasonably accurate and could easily be recalculated if the yearly costs of any of the basic cost components change. Zaporizhzhya National Technical University. This resulted in an average cost for carburizing of $0.04/pound in the early 1970s. Is there any relationship between shear strength and tensile strength of a metal? All assignable costs for a piece of equipment usually cannot be specifically assigned and tracked in an accounting system. Here, the total cost of nitrogen is known, but the hourly use cost must be assigned to each piece of atmosphere equipment that used nitrogen for purging. Related. Overall atmosphere work accounted for about 52% of overall sales. I agree with Prakarsh, I recommend you look at: dear Anil Kumar V is there any reference for these rules or its from experimental work,because we made these rules already but we don't have any reference. Process-gas costs include other gases used in the process or for process safety such as ammonia (gas or anhydrous liquid), propylene, hydrogen, argon, or as hydrocarbon additives. This data can also be seen on the graph of stress over strain and tension over extension, and also in the picture of the microstructure. For the purpose of calculating heat-treat processing cost per hour for a piece of equipment and ultimately the selling price, costs are separated into the following categories: direct costs, allocated costs, capitalized cost, and general and administrative (G&A) costs. All rights reserved. The known costs are then allocated by the attributed percentage of components in each category. A weighted factor is assigned to each piece of equipment based on its age and the severity and frequency of repairs. For large steel assemblies in particular, PWHT can be an expensive operation, and there is thus an economic incentive to avoid PWHT, wherever possible.      All cost components that are allocated will need to have a use-balance spreadsheet made so that all the areas and total commodity use are covered and balanced. For webinar sponsorship information, visit www.bnpevents.com/webinars or email webinars@bnpmedia.com. The costs could then be accurately assigned to the hourly cost of operation for each piece of equipment or similar groups of equipment. HP. Direct labor is the hourly cost of labor for those directly involved in doing the process. It also includes the cost of maintaining valves, solenoids, valve motors, oxygen-probe replacements, outside analyzer maintenance, calibrations, etc.      The oil-quenching cost is allocated by equipment roughly the same way (by utilization) except that the single-zone furnace percentage usage was decreased by about 10% each.      Table 2 calculates some selling prices per pound based on cycle length. Three of the batch tempering furnaces were also equipped for nitrogen tempering. The approach is similar, but the categories used for direct costs are different from the atmosphere furnaces. Whether PWHT is necessary depends on the fracture toughness at the minimum service temperature, the stress levels an… Using those provisions or reasonably adjusting and allocating larger cost-collecting categories of use may be necessary. The variables are the mass, metal type and target temperature. 8. Zion Industries, Inc. Heat treatment is a process or a combination of processes to treat metallic components. The basis for each allocation needs to be well thought out and make sense for the operation. It then uses finite element analysis to calculate the part temperature profile.      Another advantage of the system would be that if there is a record made of the actual total hours of operation per year for each piece of equipment, simple calculations could then be made to cross-check the calculated sales (using the equipment-hour rates) to actual total sales. The challenge is to then allocate the overall cost among the seven atmosphere furnaces. 9. Two-zone batch integral-quench, wash, temper cost analysis, Fig. Using this schedule, allowing for holidays, the available hours of operation were 350 x 24, or 10,704 hours per year for each piece of primary equipment. This article presents a simple cost/pricing system that is reasonably accurate and could easily be recalculated if the yearly cost of any of the basic 128-130A. There, the heat-treating costs were determined by corporate accountants who generally got the costs totally wrong. The temperatures metals are heated to, and the rate of cooling after heat treatment can significantly change metal's properties. Visit our updated, Heat & Corrosion Resistant Materials / Composites, Commercial Heat Treat Capabilities Directory, Materials Characterization & Testing Equipment Directory, Cutting Automotive Die Costs Using Laser Heat Treating, Heat Treating: On-Site Hydrogen Generation Can Cut Atmosphere Costs, Heat Treating: Design of Quench Systems for Aluminum Heat Treating, Part II - Agitation, Heating Elements Dictate Life-Cycle Performance and Operating Costs of Electric Furnaces and Ovens, Gasbarre Thermal Processing Systems (OEM of J. L. Becker Brand Products), Materialographic Preparation of Thermal Spray Coating Samples. Thickness (in mm) °F °C Heat Treatment. To complete the initial cost sheet for a piece of primary equipment, all of the individual contributors to utility use need to be identified and recorded. Hi, agree with all of you. Cite. The possibility also exists to record actual running time for fans, pumps, agitation motors and so much more. 1. Visit our updated, This website requires certain cookies to work and uses other cookies to help you have the best experience. The number of each category of components is assigned to each piece of primary equipment. The commercial heat-treating company from which this cost data was taken operated on a 24-7 basis. Join ResearchGate to find the people and research you need to help your work. Using thumb rules as stated above is lot easier.Â.      All sources of gas use need to be indentified, including but not limited to gas heaters, burn-off pilots, flame screens, etc. Use the phase diagram included in the lab description and show calculations. Has additive manufacturing had any impact on your business?      Shown in Table 2 are the typical average yearly costs (2002) for various commodities – natural gas, electricity, water, etc. There was a liquid-ammonia tank and liquid-nitrogen tank on site, and all furnaces had both manual and automatic nitrogen purge systems. Thesis--University of Missouri--Rolla. 5. Cost-accounting systems used by companies doing heat treating accumulate many different cost categories. Heating Rate in °C/h, °F/h. The processes used were carburizing, carbonitriding, harden and temper, atmosphere annealing and carbon restoration. The benefits would include, but are not limited to: company-paid portions of health and life insurance, workman’s-compensation premiums, federal and state unemployment tax, holiday and vacation pay, employer social security contributions, company IRA contributions, etc. Why is soaking time a function of the thickness of the part? How to calculate the grain size through SEM images? The total average nitrogen cost is then converted to a nitrogen volume that balances to the overall use in proportion to the relative endothermic gas flows. Heat exchange by conduction can be utilized to show heat loss through a barrier. Fig. Benefits are the sum total of all direct-employee fringe benefits divided by the number of employees in the category. This figure will be used for the cost of endothermic gas for all atmosphere furnaces. / Metallurgical Engineering. Nitrogen purge costs include everything associated with the purchase and use of the gas. The challenge for the customer is determining whether a proper heat treatment has been performed. Carbon Steel Typical Heat Treatment. Therefore, some allocation of costs is always necessary. By visiting this website, certain cookies have already been set, which you may delete and block. This factor is then multiplied by the category total cost to assign the proportion of the cost to the individual equipment. Heat treatment could be said to be a method for strengthening materials but could also be used to alter some mechanical properties such as improving formability, machining, etc. The average hourly cost per furnace is shown in the last column. Our free, easy-to-use HVAC load calculator will help you determine the necessary thermal output capacity (in BTUs) of any residential building. Knowing the rated utility use for the primary heating source is very helpful. The atmospheres used in the heat-treat industry have one of two common purposes: † To protect the components being pro-cessed from harmful chemical reactions      This reasonably simple and methodical system is presented for determining the hourly cost of operation for heat-treating equipment using Excel spreadsheets.      Figures 7 and 8 show cost sheets for two different frequency (RF and 3/10 kHz ) induction hardening machines.      Sales and utilization data were recorded for each piece of equipment. The G&A cost ratio is then multiplied by the total direct cost to give that contribution to cost.      In Figure 1, the average hourly cost of nitrogen for all atmosphere furnaces is determined by dividing the overall cost ($29,853) by the total utilized hours (30,071), which is $0.993. 2. All Rights Reserved BNP Media. The purpose of a furnace atmosphere var-ies with the desired end result of the heat-treating process. The metallurgic transformations take place at the specific temperature, and the part attains this temperature within a couple of minutes. Nitriding: Nitriding is a process of surface hardening in which nitrogen gas is used to obtain a hard … Local commercial heat-treating shops (that probably were closer to the actual cost) were typically charging $0.15-0.30/pound for carburizing of the same materials and case depths. Even inside one type of operation the time required may vary significantly. I need to know how long it takes for the metal to get to the target temperature, from room temperature.      There were two continuous tempering furnaces in the induction area geared for a two-hour total throughput time cycle, two batch tempering furnaces and a parts washer.      After the direct labor, benefits and total energy costs are calculated, they are totaled, resulting in the total variable cost. [William_E_Bryson]_Heat_treatment,_selection,_and_(BookZ.      All furnaces were gas fired except for the pusher, which was electrically heated. T = Holding temperature in degrees Celsius for the heat treatment. but you must know the coefficient ofÂ. Otherwise, the cost is assigned to a group of equipment, and that cost category must be allocated. The metallographic techniques are stressed, as these practices are essential for a metallurgical engineer. Alloy Steel Heat Treating. 3.   When the cost for each piece of primary equipment has been determined, the total sales for the equipment from the cost data can be compared to actual sales to identify specific areas for possible corrective action. 1.   Once derived and the commodity uses are balanced, the sheets can easily be updated annually when commodity prices change or when changes in equipment occur. Heat Treatment Hardness vs Temperature. Often, 50% of the rated value is a good first estimate of use. http://products.asminternational.org/hbk/index.jsp, Estudos de degradação e de passivação de biomateriais utilizados em cirurgia ortopédica, A electrodeposição sobre alumínio : Tratamentos prévios em solução modificada de zincato. The columns are titled: Quantity, the number of similar units; Use or Size, size or rating of the similar units measuring units for the component; Duty Cycle, the portion of time cycle the unit is functioning during the heat-treating cycle; Total Use, conversion of the units to the common-use category; and $/Unit of the Yearly Commodity Cost from Table 1. Allocated costs often are a series of smaller costs, more difficult to directly assign, for which average and cumulative costs can be more accurately assigned by specific equipment or similar equipment. These costs are included based on the ratio of G&A cost to total costs. Heat Treating Aluminum Alloys. Is there a formula to calculate time to Final temp for a mass of metal? Generally, costs are grouped with some other equipment. What is Grain Size and Grain Number? The Heat Treatment Process Calculation tool is structured according to the type of heat treatment process as shown in figure 8. Heat treatment, per part : The per unit price that the vendor has quoted. a sous vide process being assessed. All Answers (17) 1st Jun, 2016. This data can then be used to determine the number of hours over which the costs will be distributed. weld heat treatment becomes mandatory is much less. B.S. For a wall of steady thickness, the rate of heat loss is given by:      It is necessary to keep accurate records regarding the actual amount of time that each piece of equipment is in production over an extended period of time (preferably a year). The fourth column lists the certified equipment.      If the cost for the commodity (electric, gas, gases, water, manpower, depreciation, etc.) The overall cost of nitrogen for the year is known to be $29,853. By reviewing and understanding the key criteria of a furnace chart, the customer can have confidence in the steel’s delivered performance. If we weld any material and make it too cool in air after welding,  its Grain Size and Grain Number will increases or decreases ? Quenchant costs include the cost of additive quench materials such as water, polymers, oils, gases used for quenching, etc. The selling price for this equipment is $25.13 per hour. The third column lists the number of carbon-control systems for each piece of atmosphere equipment. Finally, the total hourly cost is the total of the last three figures in the right column. This same methodology is used to assign the individual equipment costs for fixtures/tooling.      Later, as manager of a commercial heat-treating operation where errors in heat-treat pricing could affect the very success and profitability of the company, accurate pricing was an important issue. In Figure 2, the primary equipment is shown in the first column, and the types of process-control systems are broken into three groups: A is temperature-control systems, B is oxygen-probe carbon-control systems and C is certification to AMS 2750 systems. After 760 C for 2 hours PWHT (Post Weld Heat Treatment) of welded material, its Grain Size and Grain Number will increases or decreases as compare to Point (1) weld? I have a sample of size 32 x 32 x 24mm.      Representative cost sheets for two of the atmosphere furnaces, the Pacific two-zone batch and the pusher line, are shown in Figures 5 and 6. The Ovako Heat Treatment Guide is a tool developed to increase the understanding of how different alloying elements influence steel hardness after quenching and/or … Heat Treatment. 1.   ASM Committee on Heat Treating, The Cost of Heat Treating, Metal Progress, American Society for Metals, July 1954, pps. I.e., are we assuming that at this time the temperature achieved will be austenitic solid solution of carbon in gamma iron zone above 1130ºC? Sometimes this data is given on the original prints furnished with the equipment. The electrical component cooling used distilled water, which was cooled using shell and tube heat exchangers (as was the polymer quenchant) with water from a large 5,000-gallon treated-water system. Yes there are certain thumb rules for certain classes of alloys. By visiting this website, certain cookies have already been set, which you may delete and block. Select steel variant. When questioned, those responsible for quotations and pricing were not sure how most of the prices were originally derived, but “the prices had been determined several years ago and then annually updated.”. 1. Although it is recognized that each heat-treating operation is unique and the prices presented in this paper may not be applicable, the technique presented can be useful in the derivation of accurate costs and prices.