NM360耐磨钢回火工艺优化的研究

Study on Tempering Process Optimization of NM360 Wear Resistant Steel

针对NM360耐磨钢板回火不充分、内应力没有充分释放的问题,研究了不同回火温度对NM360耐磨钢板的显微组织和力学性能的影响,并对回火工艺进行了优化。结果表明,耐磨钢在（900±10）℃保温12 min后淬火并在450℃回火时,随着回火时间的延长,试样的硬度逐渐降低,冲击吸收功先增大后减小,在回火时间为2.5 h时达到最大值。淬火后在300～400℃回火,耐磨钢处于回火脆性区。在450℃回火2.5 h时,耐磨钢获得大量回火马氏体组织,使钢具有较高的强度和高韧性,达到最佳的力学性能。通过回火工艺的优化,最终确定的最佳回火温度为450℃,最佳回火保温时间为2.5 h。

Aiming at the problems that the tempering of NM360 wear-resistant steel plate was not sufficient and theinternal stress was not fully released, the influences of different tempering temperatures on the microstructure and mechanicalproperties of NM360 wear-resistant steel plate were studied and the tempering process was optimized. The results show thatafter quenching at （900±10） ℃ for 12 min and then tempering at 450 ℃ ,with the increase of tempering time, the hardness ofthe sample decreases gradually, and the impact absorption energy increases firstly and then decreases. The maximum value isreached when the tempering time is 2.5 h. After quenching and then tempering at 300-400 ℃, wear resistant steel is in thetemper brittleness area. When tempering at 450 ℃ for 2.5 h, a large numbers of tempered martensite microstructure areobtained, and the steel has a high strength and high toughness, which achieve the best mechanical properties. The optimumtempering temperature is 450 ℃ and the optimum tempering holding time is 2.5 h.