In order to obtain carbide in ferrite matrix uniformly distributed fine, small, uniform, round organization, after the cold processing and final quenching and tempering organization preparation. Spheroidizing annealing process of traditional is slightly higher than the Ac1 temperature (such as GCr15 to 780~810 ℃) after incubation with furnace cooling slowly (25 ℃ /h) to 650 ℃ natural air cooling. The technique of heat treatment for a long time (more than 20h), and after annealing carbide particles is not uniform, and the performance influence subsequent cold working and final quenching and tempering organization. Then, according to the characteristics of the transformation of undercooled austenite, development of isothermal annealing process: after heating and fast cooling to Ar1 below a certain temperature range (690~720 ℃) isothermal, in isothermal process completed the transformation from austenite to ferrite and carbide, after finishing the transformation can be directly natural air cooling. The advantage of this process is to save the time of heat treatment (the whole process about 12~18h), carbide treated tissue is fine and uniform. Another time saving process is repeated spheroidizing annealing: first heated to 810 ℃ cooling to 650 DEG C, and then heated to 790 ℃ after cooling to 650 ℃ natural air cooling. The process can save time, but the process is complex.



Other News:
Spheroidizing annealing of high carbon chromium bearing steel
Plane needle roller bearings to clearance requirements
Bring Timken bearing solution for all machine tools to participate in CIMT2013
The use of early warning signal will be faulty bearings
Schaeffler headquarters in greater China II project groundbreaking
Bearing giant United States owned by the Timken Company business officially settled in Hunan
Bearing selection method
Schaeffler revenue this year is expected to remain optimistic