淬火工艺参数对BR1500HS材料性能与微观组织的影响规律研究∗

摘要

This paper researched the tensile strength,hardness and the true stress-strain curves of BR1500HS at different temperature and holding time through the tensile tests.And the microstructure at different quenching condition was investigated,the fracture morphology was analyzed by SEM.Then the effect of quenching param-eters on material properties and microstructure was obtained.The hardness,tensile strength and ductility reach their maximum at 900 ℃(holding 2 min).At the temperature range from 850 to 920 ℃,the fracture morpholo-gy is better.When the temperature is beyond Ac3(811 ℃)and holds enough time,the ferrite and pearlite in the original samples can be transferred into austenite,and the microstructure after quenching is total martensite. This can guide the parameters choosing in the actual production.%通过高温拉伸实验研究了 BR1500HS 高强钢在不同加热温度与保温时间下的抗拉强度、硬度及真实应力-应变曲线，并通过光学显微镜观察了不同淬火温度下的微观组织结构，利用扫描电子显微镜 SEM分析了淬后材料的断口形貌。得出了不同的淬火工艺参数对BR1500HS抗拉强度、硬度、真实应力-应变曲线、微观组织结构以及断口形貌的影响规律。在奥氏体化温度为900℃并保温2 min 时淬火，材料硬度和抗拉强度均达到峰值，延展性也最好；在850~920℃温度区间韧窝断口形貌较好；淬火温度超过 Ac3(811℃)且在保温时间足够长时，可使试样中的铁素体和珠光体完全转变为奥氏体，淬后试样的组织为完全的马氏体。这为实际生产的工艺参数选择提供了指导。