1、 Manufacturing StandardsFord Motor Company199409 ANNEAL - FULL W-HT1-14Engineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 1 of 51. SCOPE: This process standard outlines the method for full annealing ofsteel sheet/bar stock or steel parts/stock to form pearlite in
2、 hypoeu-tectoid steels and pearlite and/or speriodal carbides in eutectoid andhypereutectoid steels.2. REFERENCES:- Q101, Ford Quality Standard (or successor document as defined in theapplicable purchase order)- W-HTX-1, Ford Manufacturing Standard- W-HTX-12, Ford Manufacturing Standard3. APPLICATIO
3、N: This Standard applies to ferrous parts and materials whichare heated in a furnace above the “upper critical“ temperature (the Ae3for hypoeutectoid steels and the Aecm for hypereutectoid steels) with aprotective atmosphere (or in a vacuum). For certain parts/configurationsof relatively thick cross
4、section and with end uses that may permit somesurface decarburization or scaling, an air atmosphere may be permittedprovided concurrence is received from the affected Ford SQE or quality/Engineering Activity and documented in the control plan.NOTE: Control of the microstructure of the product/mater
5、ial prior toanneal is recommended in order to improve the consistency of the productresulting from the full anneal cycle.4. REQUIREMENTS:4.1 PROCESS CONTROL: Suppliers utilizing this process standard must beable, by means of their existing process practices and records, toshow evidence of control of
6、 the process as per Ford Quality SystemStandard Q-101. Appropriate statistical tools shall be used toanalyze significant process parameters and product characteristicsand appropriate reaction plans implemented in order to assurecontinuous reduction of variation in the final product. Users ofthis pro
7、cess are referred to Ford Manufacturing Standard W-HTX-1(for parts with heat-treated characteristics denoted as Control Item() or for parts with Engineering prints denoted as “Must conform toQ-101, Appendix E” or “Must conform to Q-101, Appendix F”) or toW-HTX-12 (for heat-treated parts not covered
8、by W-HTX-1) in whichcontrol practices are outlined.The process, equipment, heat treatment parameters, loading, chargingsequence, and test procedure must form part of the component partcontrol plan and take into account any Engineering requirementsshown on the final part drawing which override specif
9、ic items inthis Standard.Manufacturing StandardsFord Motor Company199409 ANNEAL - FULL W-HT1-14Engineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 2 of 54.2 PROCESS: Full annealing may be performed in a:- batch-type muffle or radiant tube furnace.- batch-anneal fu
10、rnace with inner cover (includes box,carbottom, bell, and pit furnaces)- continuous furnace with cooling zones sufficient toachieve appropriate cooling rates to produce desiredhardness and microstructure.- other thermal processing unit approved by the affectedFord SQE or Quality/Engineering activity
11、 and documentedin the control plan.The equipment must be capable of heating parts uniformly up to andwithin the range of 730-925C (1350-1700F). (A higher temperaturecapability may be necessary if a low carbon material is to beannealed).4.3 LOADING: Parts shall be suitably loaded in such a manner to
12、assurethat all parts/material are able to be properly heated to therequired temperature and for the necessary time.Components/material must be thoroughly clean, dry and free of dirt,oil, soap residue, chips, etc. prior to introduction to the furnace.Material from different steel mill heats, hot mill
13、 schedules, ormelts which require different annealing times and/or temperatures toensure that a given lot is processed as necessary to attain thespecified metallurgical properties SHALL NOT BE MIXED OR PROCESSEDTOGETHER.4.4 FURNACE ENVIRONMENT: Atmospheres suitable for full annealinginclude exotherm
14、ic, dissociated ammonia, or nitrogen base withhydrogen (less than 5% H2). The neutral furnace atmosphereutilized shall be appropriate for the grade of steel involved. Forparts/stock with adequate cross-sections and end uses for whichlimited decarburization and scaling are permitted, an air furnaceat
15、mosphere is acceptable if approved by the affected Ford SQE orQuality/Engineering activity and documented in the control plan.Vacuum-type furnaces may be employed in lieu of the aforementionedatmospheres.Manufacturing StandardsFord Motor Company199409 ANNEAL - FULL W-HT1-14Engineering Standards & Pr
16、inted copies are uncontrolled.Systems Engineering (ESSE) Page 3 of 54.5 TEMPERATURE: The temperature shall be controlled within +/-5C(+/- 10F) of the set point, as evidenced by continuous recordingpyrometers. Also, the mean isothermal temperature shall not differby more than 15C (27F) from one part
17、of the load and another asmeasured by use of thermocouples within the load. (Note: whilethe use of thermocouples within the load is recommended, it is notrequired in all production lots except for periodic verification oftemperature consistency as documented in the control plan).4.6 CYCLE: A full an
18、neal cycle involves completely austenitizing thematerial by heating to and holding at a temperature above the uppercritical (Ae3 or Aecm as appropriate). The material is then slow-cooled to assure the appropriate structure and hardness.4.7 MICROSTRUCTURE: The microstructure of the part/shape/materia
19、lshall be course pearlite (and ferrite in the instance of low carbonsteel).4.8 HARDNESS: Unless otherwise specified, the hardness shall bechecked on the Rockwell “B“ scale.4.9 SUPPLIERS RESPONSIBILITY: The process which has been approved tomeet the requirements of this Manufacturing Standard, as pro
20、vided inthe Ford Quality System Standard Q-101 for product application, orby the specifying authority for non-production application, shallnot be changed without prior approval of the responsible Ford MotorCompany authority.5. APPROVAL OF NEW SUPPLIERS: Suppliers approved to this process mustbe revi
21、ewed by the appropriate Ford SQE or Quality/Engineering activity.6. GENERAL INFORMATION: The information given below is provided forclarification and assistance in meeting the requirements of thisStandard.Figure 1 and 2 (Iron-Carbon Phase Equilibrium Diagram and Time-Tempera-ture-Transformation Diag
22、rams, respectively) are intended to serveas a general illustration of the processes covered by this Standard.They are not intended to portray all diagrams of the various alloycombinations that may be processed using this Standard.Manufacturing StandardsFord Motor Company199603 ANNEAL - FULL W-HT1-14
23、Engineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 4 of 5FIGURE 1IRON - CARBON PHASE EQUILIBRIUM DIAGRAMManufacturing StandardsFord Motor Company199603 ANNEAL - FULL W-HT1-14Engineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 5 of 5FIGURE 2TIME - TEMPERATURE - TRANSFORMATION DIAGRAMS
