Chemical composition: C2.05, Si1.40, Mn 0.78, Cr 26.03, Ni0.81, Mo0.35
The commonly used heat treatment process of high chromium cast iron is to heat to 950~1000℃, and then after 200~260℃ of low temperature tempering.
High temperature mass pelleting treatment 1140~1180℃ insulation for 16h air cooling, can significantly improve the impact toughness and wear resistance. High temperature spherical treatment can make all carbides globular, can eliminate or reduce the separation of large mass and continuous network carbide on the matrix, the spherical carbide is supported by more uniform matrix, especially supported by a certain number of austenite. If the insulation time is appropriately reduced, the thin section parts can also be effective. The deficiency of this process is that the process consumes more heat energy.
Heat to 1050℃, and then conduct 550℃ tempering, how will the effect be?
To control the heating speed, it is best to keep warm for a certain time at 650 hours. I've done it before, just on fire. Hardness can achieve 61- - - -65 HRC
Mature process is: casting after the softening and annealing, easy to process, processing after air cooling quenching and low temperature to stress tempering. The use of hardness is generally required for HRC 58-62, mostly used for such as slurry pump parts and other wear and wearing parts.
We are a high chromium production base, generally providing Cr 24, Cr 26, Cr 28, Cr15Mo3, etc., including the softening annealing in the middle and quenching and tempering. We now use quenching liquid quenching, quenching process parameters are: 650 degrees insulation for 2 hours, heating to 960 degrees insulation for 3.5 hours quenching; tempering temperature 380~400,4~6 hours insulation. Grinding ball specification φ 40- φ 80.
The process is 1050 quenching + 250~350 tempering
