退火工艺对SPCC冷轧薄板组织及性能的影响

对低碳铝镇静钢(SPCC)冷轧薄板进行了模拟罩式退火, 分析其在不同退火条件下的组织及性能。结果表明, SPCC的再结晶温度为560 ℃, 再结晶温度范围为520～600 ℃。660～680 ℃双台阶退火1 h后, R_eL低于190 MPa, R_m为300 MPa, A为43%, 达到了深冲压用钢的性能指标。采用全速加热(第一阶段300 ℃/h, 第二阶段150 ℃/h)680 ℃保温1 h后, 性能完全满足一般用钢的要求。实验结果表明, 退火板中链状分布的渗碳体主要来自于珠光体中片状渗碳体的球化。

Effects of Annealing Process on Microstructure and Mechanical Properties of SPCC Cold-rolled Sheet

Simulated bell-type annealing of the cold-rolled sheet made of low-carbon aluminum killed steel (SPCC) was carried out to investigate its microstructure and properties under different annealing conditions. The results show that recrystallization temperature of SPCC is 560 ℃ in the range of 520～600 ℃. After double-step annealing for 1 h at a temperature ranging from 660 ℃ to 680 ℃, R_eL is less than 190 MPa, R_m is about 300 MPa, and A is 43%. These indexes of the steel meet the performance requirements of deep drawing. After full speed heating(first stage at 300 ℃/h, the second stage at 150 ℃/h) and temperature holding at 680 ℃ for 1 h, the properties of the steel fully meet the requirements of general use. In addition, the results also show that the cementite with chain-like distribution mainly is from the spheroidization of flake cementites in pearlite.