回火工艺对冷轧釉化用钢组织和性能的影响

In this paper the reasons why the yield strength of a cold rolled enameling steel decreases after enameling firing at 760 C and 815 C, and the effect of tempering process on the microstructure and mechanical properties are studied. The results show that after heat treatment at 760 C and 815 C by air cooling, the lump phase enriched with the elements of C, Mn and Si appears along the grain boundaries, which leads to the yield strength reduction. After tempered at 400 C~600 C, as the increase of the tempering temperature, the lump phase disappears gradually and transforms to lamellar pearlite, resulting in yield strength increasing. When tempered at 700 C, cementite particles appear in the grain boundaries and the yield strength decreases slightly. For the samples after heat treatment at 815 C by air cooling, the tempering at 200-300 C does not increase the yield strength evidently. After tempered at 400 C~600 C for 5 min, the yield strength is increased about 40MPa compared to that of as cold rolled sample.