摘要
针对22MnB5热成形钢,利用Gleeble热模拟机研究了其在Nb、V、Ti微合金化下的显微组织和力学性能。结果表明,Ti微合金化后,随C含量的增加,试验钢的强度和硬度会明显增高,主要是因为C提升了试验钢的淬透性;Nb、Ti复合微合金化后,Nb的添加会降低试验钢的强度和硬度,可能是因为NbC的析出使固溶C含量降低;Nb、V、Ti共微合金化后V含量的变化对硬度的影响较弱,V含量增加到0.30%才能有效提高试验钢的强度和硬度。利用EBSD表征了微合金化后22MnB5热成形钢的马氏体亚结构,发现原始奥氏体晶粒尺寸细小,室温下马氏体组织由束、块及板条构成,马氏体块的尺寸细小,有些马氏体块的尺寸小于2μm。马氏体板条界的取向差主要集中在1°左右,为小角度晶界。
For 22MnB5 hot stamping steel,the microstructure and mechanical properties of the steels microalloyed with Nb,V,and Ti were studied by Gleeble thermal simulator.The martensitic substructure of the microalloyed 22MnB5 hot stamping steel was characterized by EBSD.The results show that after Ti microalloying,the strength and hardness of the tested steel increases significantly with the increase of C content,mainly because C improves the hardenability of the tested steel.After Nb and Ti co-microalloying,the addition of Nb reduces the strength and hardness of the tested steel,due to that the precipitation of NbC can reduce the content of solid-soluted C.After Nb,V,and Ti co-microalloying,the variation of V content has a minor impact on the hardness,and only by increasing V content up to 0.30%can improve the strength and hardness of the tested steel.The EBSD results show that the prior austenite grain size is fine,and the martensite structure at room temperature consists of bundles,blocks,and laths.The sizes of the martensite blocks are fine,some of which are less than 2μm.The misorientation of the interfaces between martensite laths is mainly concentrated at about 1°,which belongs to low-angle grain boundary.
作者
张翔宇
张宇
代春朵
刘华松
闫智然
Zhang Xiangyu;Zhang Yu;Dai Chunduo;Liu Huasong;Yan Zhiran(Vanadium and Titanium Branch,Ansteel Beijing Research Institute Co.,Ltd.,Beijing 102200,China;Steel Branch,Ansteel Beijing Research Institute Co.,Ltd.,Beijing 102200,China)
出处
《金属热处理》
北大核心
2025年第8期14-20,共7页
Heat Treatment of Metals
基金
鞍钢集团北京研究院有限公司院立项。
关键词
热成形钢
微合金化
显微组织
力学性能
马氏体
hot stamping steel
microalloying
microstructure
mechanical properties
martensite
作者简介
张翔宇(1995-),男,工程师,博士,主要研究方向为特钢设计开发,E-mail:444566088@qq.com。
