等温温度对Ti-Mo微合金高强双相钢相变及组织性能的影响  

Effect of isothermal temperature on phase transformation,microstructure and properties of Ti-Mo microalloyed high strength dual phase steel

作　　者：何平[1] 王巍[2] 李群芳 王礼凡 党正卓 胡海江[1] HE Ping;WANG Wei;LI Qun-fang;WANG Li-fan;DANG Zheng-zhuo;HU Hai-jiang(State Key Laboratory of Refractories&Metallurgy,Wuhan University of Science&Technology,Wuhan 430081,China;Baoshan Iron&Steel Co Ltd,Shanghai 201999,China)

机构地区：[1]武汉科技大学耐火材料与冶金国家重点实验室,湖北武汉430081 [2]宝山钢铁股份有限公司中央研究院,上海201999

出　　处：《材料热处理学报》2024年第8期146-153,共8页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金青年基金(51704217);国家自然科学基金面上项目(51874216)。

摘　　要：采用热模拟实验、光学显微镜、显微硬度仪和透射电镜等研究了等温温度对Ti-Mo微合金高强双相钢相变、组织及性能的影响。结果表明:当等温温度在750~725℃时,实验钢组织主要为马氏体+少量贝氏体或铁素体,随着等温温度降低(≤700℃),铁素体含量增多,排碳行为增加了过冷奥氏体的稳定性,抑制了中低温区贝氏体相变,在随后的冷却阶段,过冷奥氏体更倾向转变为马氏体。铁素体与马氏体的显微硬度均随等温温度降低而增加,但进一步降低温度,马氏体硬度基本保持稳定(361 HV0.1);650℃时铁素体显微硬度最高(242 HV0.1),这主要是由于铁素体内部产生了大量细小的相间析出,同时析出强化作用减小了铁素体与马氏体的硬度差异,降低了双相钢强度对马氏体体积分数的依赖性,等温温度较高时,相间析出形成被抑制。Effect of isothermal temperature on phase transformation,microstructure and properties of Ti-Mo microalloyed high strength dual phase steel was studied by means of thermal simulation experiments,optical microscope,microhardness tester and transmission electron microscopy.The results show that when the isothermal temperature is between 750-725℃,the microstructure of the experimental steel is mainly martensite+a small amount of bainite or ferrite.As the isothermal temperature decreases(≤700℃),the ferrite content increases,and the carbon removal behavior increases the stability of undercooled austenite,inhibiting the bainite transformation in the medium and low temperature zone.In the subsequent cooling stage,undercooled austenite tends to transform into martensite.The microhardness of both ferrite and martensite increases with the decrease of isothermal temperature,but when the temperature is further reduced,the hardness of martensite remains basically stable(361 HV0.1),the highest microhardness of ferrite is achieved at 650℃(242 HV0.1),mainly due to the generation of a large number of fine interphase precipitates inside the ferrite.At the same time,the strengthening effect of precipitates reduces the hardness difference between the ferrite and the martensite,reducing the dependence of dual phase steel strength on the martensite volume fraction.When the isothermal temperature is high,the formation of interphase precipitates is inhibited.

关 键 词：铁素体/马氏体双相钢 Ti-Mo微合金钢 等温相变 相间析出 显微硬度 

分 类 号：TG142.3[一般工业技术—材料科学与工程]