FORD W-HT1-15-1994 NORMALIZING NORMALIZING AND TEMPERING《正火处理 正火处理和回火处理》.pdf

1、 Manufacturing StandardsFord Motor Company199409 NORMALIZING/NORMALIZING W-HT1-15AND TEMPERINGEngineering Standards (e.g., in multi-zoned furnaces,it is recommended that the MINIMUM gap spacing be equivalent to onezone-length). It should be noted that a greater gap may benecessary.Material from diff

2、erent steel mill heats, hot mill schedules, ormelts which require different normalizing times and/or temperaturesto ensure that a given lot is processed as necessary to attain thespecified metallurgical properties SHALL NOT BE MIXED OR PROCESSEDTOGETHER.4.4 FURNACE ENVIRONMENT: An air atmosphere sha

3、ll be employed in boththe furnace and the cooling zones.4.5 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 of the load

4、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 normalize cycle inv

5、olves heating the components/materialto approximately 55C (100F) above the upper critical temperature(Ac3 for hypoeutectoid steels) (Acm for hypereutectoid steels) forsufficient time to assure complete austenitization of themicrostructure. The components/material are then air cooled in sucha fashion

6、 that cooling in any portion of the component/material isnot restricted or accelerated relative to other sections.Manufacturing StandardsFord Motor Company199409 NORMALIZING/NORMALIZING W-HT1-15AND TEMPERINGEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 3 of

7、4- Medium carbon alloy steel components, for instance, may require atemper operation after normalize to reduce variations in hardnessand microstructure. The components should be soaked for 1 hourminimum at the appropriate temperature.4.7 MICROSTRUCTURE: The microstructure of the component/material s

8、hallbe a fine equiaxed grain structure (approximately No. 6-8 per ASTMStandard E112) with fine pearlite and ferrite (in lower carbongrades).4.8 HARDNESS: Unless otherwise specified, the hardness shall be checkedon the Rockwell “B“ scale.4.9 SUPPLIERS RESPONSIBILITY: The process which has been approv

9、ed tomeet the requirements of this Manufacturing Standard, as provided in the FordQuality System Standard Q-101 for product application, or by the specifyingauthority for non-production application, shall not be changed without priorapproval of the responsible Ford Motor Company authority.5. APPROVA

10、L OF NEW SUPPLIERS: Suppliers approved to this process mustbe reviewed by the appropriate Ford SQE and/or Quality/Engineering activity.6. GENERAL INFORMATION: The following information is provided for clarifi-cation and assistance in meeting the requirements of this Standard.Figure 1 (Iron-Carbon Ph

11、ase Equilibrium Diagram) is 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 NORMALIZING/NORMALIZING W-HT1-15AND TEMPERINGEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 4 of 4FIGURE 1IRON - CARBON PHASE EQUILIBRIUM DIAGRAM