3. The second and third states of heat treatment after cold working are as follows:
3. The second and third levels of heat treatment after cold working are as follows:
HR - cold working + stress relief; HT - cold working + ordered strengthening; HE - cold working + end annealing
HR: HR01 - 1 / 4 hard + stress relief; HR02 - semi-hard + and stress relief; HR04 - hard + and stress relief; HR06 - extra hard + and stress relief; HR08 - elastic + and stress relief; HR10 - high elastic + and stress relief; HR12 - special elastic + and stress relief; HR50 - drawing + stress relief; HR90 - fin forming + stress relief
HT: HT04 - hard + ordered strengthening; HT08 - elastic + ordered strengthening
HE: HE80 - hard drawing + end annealing
4. Second and third level representation methods of annealing state (O):
The second and third level of annealing state (O) are divided into two representation methods: annealing to meet the nominal average grain size and annealing to meet the mechanical properties.
1). Method of expressing the second and third level annealing states that meet the nominal average grain size:
OS--Annealing with grain size requirements, the three digits added thereafter divided by 1000 is the nominal average grain size, in mm; for example, the nominal average grain size of OS005 is 0.005mm, and the nominal average grain size of OS200 is 0.2mm
2). Method of expressing the second and third level annealing states that meet the mechanical properties:
O1--Casting state + heat treatment; O2--Hot forging + heat treatment; O3--Hot extrusion + heat treatment; O4--Hot piercing + heat treatment; O5--Quenching and tempering annealing; O6--Annealing; O7--Complete softening annealing; O8--Annealing to specific properties
O1: O10--Casting + annealing (homogenization); O11--Casting + precipitation heat treatment
O2: O20--Hot forging + annealing; O25--Hot rolling + annealing
O3: O30--Hot extrusion + Annealing; O40 - hot extrusion + precipitation heat treatment
O4: O40 - hot piercing + annealing
O5: O50 - light annealing
O6: O60 - soft annealing; O61 - annealing; O65 - stretch annealing; O68 - deep drawing annealing
O7: O70 - complete soft annealing
O8: O80 - annealing to 1/8 hardness; O81 - annealing to 1/4 hardness; O82 - annealing to 1/2 hardness
