Review
T12 steel, high carbon content because, after quenching have more excess carbon, produced by wear resistance and hardness are not suitable for shock load, cutting speed is not high, constant heat cutting edge tools, such as the production lathes, planer of turning, milling, drilling; can be made reamers, reamer, tap, die, scrapers, gauge, cut tobacco knife, rasp, and the small size of the cold section trimming die, punching die and so on.
The chemical composition of T12
T12 steel chemical composition (GB1298-86) w /%
C Si Mn S P
1.15 ~ 1.24 ≤ 0.35 ≤ 0.40 ≤ 0.030 ≤ 0.035
T12 thermal processing
T12 steel thermal processing
Item no heating temperature / ℃ start temperature / ℃ termination temperature / ℃ cooling
Steel ingot
Steel billet 1100 - 1150
1050 ~ 1100 1050 ~ 1100
1020 ~ 1080 850 ~ 750
800 ~ 750 700 ℃ after cold sand
After slow cooling 700 ℃
Note: Do not heat too long holding time, to prevent decarburization; become useful when the last fire, the temperature not higher, 700 ℃ prior to rapid cooling, in order to avoid mesh carbide precipitation; 700 ℃ after, should slow cooling, so as to avoid thermal stress generated the crack.
