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. Heat treatment is the process of heating and cooling metals to change their microstructure and to bring out the physical and mechanical characteristics that make metals more desirable. Heat exchange by conduction can be utilized to show heat loss through a barrier. These factors include energy unit conversions and liquid-to-gas conversions for various commodities used in the heat-treating processes. Direct costs are those directly associated with the equipment or equipment grouping for which the costs per hour of operation are being determined. This same methodology is used to assign the individual equipment costs for fixtures/tooling. Typically, the range is 13 – 20 mm, and even below 13 mm, a series of strict conditions have to be met before post weld heat treatment can be waived.      The allocated costs (as applicable) are entered next with the allocated portion entered as “Allocated $/Year.” This number is then divided by the utilized hours/year to give the contribution of the allocated costs to the total cost. How can I calculate the time it takes for the metal to reach the target temperature? The challenge is to then allocate the overall cost among the seven atmosphere furnaces. Hi, agree with all of you. Tell me how we can improve. Cite. Allocation of Repairs/Maintenance and Fixture/Tooling Costs. Nitrogen purge costs include everything associated with the purchase and use of the gas. In another example, according to a Latrobe Steel data sheet, 17-4 precipitation hardening stainless steel can typically be expected to shrink by 0.0004 to 0.0006 inch/inch (size change per unit of length) when aging from Condition A to Condition H-900 and 0.0018 to 0.0022 inch/inch when aging from Condition A to Condition H-1150. Zion Industries, Inc.      Sales and utilization data were recorded for this equipment. There, the heat-treating costs were determined by corporate accountants who generally got the costs totally wrong. 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 Liquid flowing through a pipe greatly increases heat loss, and this calculator does not yet support calculations for flowing liquids. 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. They used many averages and allocated most of the cost components without using costs associated directly with the specific operation or process.      The other useful commodity cost needed in Table 2 is the average cost of endothermic gas, which is based on the then-current labor and utility costs. 2.   The data can be used to calculate selling prices (per pound or each piece) when the cycle length and loading characteristic are known. if for lesser time then what is the relationship between Heattreatment time and sample size. A log regarding usage of equipment was maintained as well as other important costing information using Excel® spreadsheets. Allocation of nitrogen purge usage (balancing), Fig. For instance: If I put 40 lbs of aluminum in my oven and it takes 120 seconds for the oven to recover and reach target temperature, is the metal also at target temperature? This data can then be used to determine the number of hours over which the costs will be distributed.      A wide range of parts were heat treated in the facility including various shafts, gears, sprockets, bushings, aircraft connecting rods and related engine parts, etc. 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? 1.   ASM Committee on Heat Treating, The Cost of Heat Treating, Metal Progress, American Society for Metals, July 1954, pps. Two-zone batch integral-quench, wash, temper cost analysis, Fig. You can find the required information about the required time in the books and handbooks on heattreatment of metallic materials. Materials heat treated were steel, steel investment castings, aluminum castings, various cast irons, and wear- and corrosion-resistant cast iron. Single-row, nine-tray, pusher-line cost analysis, Fig. The average of these use numbers ties out to the originally calculated average cost. Sometimes this data is given on the original prints furnished with the equipment.      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. Finally, a factor is determined in the fourth column, which is the weighted value for the equipment category. An advantage of the system would be that if the loading characteristics of individual parts a… For example those proposed by Anil Kumar V. Cite      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. For temperiing it would be 2 Hr/Inch. The two-zone batch atmosphere furnaces were kept in certification to AMS 2750 as well as two companion tempering furnaces. It also includes the cost of maintaining valves, solenoids, valve motors, oxygen-probe replacements, outside analyzer maintenance, calibrations, etc. Fig. The commercial heat-treating company from which this cost data was taken operated on a 24-7 basis. © 2008-2021 ResearchGate GmbH. The first hourly cost sheet to be prepared is the determination of the average cost of endothermic gas, which is then used as a cost factor for the operational cost of each type of atmosphere furnace. Calculation of heat treatment parameters. The costs could then be accurately assigned to the hourly cost of operation for each piece of equipment or similar groups of equipment. These equations are used to calculate heat loss from the building subjected to heat treatment and the necessary energy consumption to heat the building to the desired temperature. So, why is the soaking time (for hardening) is as high as 4min/mm (60min per inch)? There were two direct-fired, high-heat (up to 2000?F) furnaces with manipulators, cool-down fan station and 2,000- to 5,000-gallon water-quench tanks. The metallurgic transformations take place at the specific temperature, and the part attains this temperature within a couple of minutes. Calculation: for heat on object. 3. 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