低碳贝氏体钢等温淬火变体选择与特殊晶面定量化表征  

Selection of Isothermal Quenching Variants and Quantitative Characterization of Special Crystal Faces of Low Carbon Bainite Steels

作　　者：杨劼[1] 任慧平[1] 王海燕[1] 高雪云[1] 刘宗昌[1] YANG Jie;REN Huiping;WANG Haiyan;GAO Xueyun;LIU Zongchang(College of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,Inner Mongolia,China)

机构地区：[1]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《材料导报》2024年第9期212-219,共8页Materials Reports

基　　金：国家自然科学基金(51764047)。

摘　　要：为分析低碳贝氏体钢(15Cr12CuSiMoMn)的变体选择与特殊晶面取向差分布对其力学性能的影响,以及变体选择与晶面取向差之间的相互联系,对实验钢充分奥氏体化后在指定温度进行等温淬火热处理,随后分析并表征等温转变过程中变体选择的演变规律与特殊晶体学面取向差分布规律。结果表明,实验钢所得{100}极图与{100}标准极图吻合,贝氏体变体与母相奥氏体的位向关系符合K-S关系,随着等温淬火温度的升高,贝氏体相变速率加快,变体选择能力降低,同时大角度晶界HAGBs(45~65°)、小角度晶界LAGBs(2~15°)界面含量减少。等温淬火60 min发现320℃时原奥氏体晶粒内同一CP组中V1/V2、V1/V3、V1/V5等变体对数量较340℃时分别增加2.4%、15%、1.1%,同一CP组中的贝氏体变体可增加大角度晶界;320℃等温淬火后实验钢具有较大的整体界面取向差、解理面(100)取向差以及滑移面(110)取向差,其整体界面取向差范围为3.2~62.5°,解理面(100)取向差范围为6.9~47.8°,滑移面(110)取向差范围为1~29.2°。通过控制贝氏体变体分布与含量进而影响其有效解理面(100)取向差与滑移面(110)取向差的分布范围,增大特殊晶面取向差范围有利于优化贝氏体组织,最终达到改善其力学性能的目的。In order to analyze the influence of variant selection and special crystal plane misorientation distribution of low carbon bainite steel(15Cr12CuSiMoMn)on its mechanical properties,and the correlation between variant selection and crystal plane misorientation,the experimental steel was subjected to isothermal quenching heat treatment at a specified temperature after fully austenitizing,and then the evolution law of variant selection and the distribution law of special crystallographic plane misorientation during isothermal transition were analyzed and characterized.The results show that the{100}standard polar diagram is basically consistent with the{100}polar diagram of the experimental steel.The orientation relationship between the bainite variant and the parent austenite conforms to the K-S relationship.With the increase of isothermal quenching temperature,the bainite transformation rate is accelerated,and the ability of variant selection is reduced.At the same time,the content of HAGBs(45-65°)and LAGBs(2-15°)is decreased.After isothermal quenching for 60 min,it is found that the number of variant pairs V1/V2,V1/V3,V1/V5 in the same CP group increases by 2.4%,15%,1.1%in 320℃compared with 340℃,and the bainite variant in the same CP group can increase the LAGBs.After isothermal quenching at 320℃,the experimental steel has large overall interfacial misorientation,cleavage plane(100)misorientation and slip plane(110)misorientation.The misorientation of the overall plane ranges from 3.2°to 62.5°,the misorientation of the cleavage plane(100)ranges from 6.9°to 47.8°,and the misorientation of the slip plane(110)ranges from 1°to 29.2°.By controlling the distribution and content of bainite variants,which affects the distribution range of the effective cleavage surface orientation difference(100)and the slip surface orientation difference(110),increasing the range of special crystal plane orientation difference is conducive to optimizing the bainite structure.

关 键 词：贝氏体钢 取向分布 变体选择 取向差 

分 类 号：TG142.1[一般工业技术—材料科学与工程]