Mn-V低合金钢冲击韧性低原因分析  

Cause Analysis of Low Impact Toughness of Mn-V Low Alloy Stee

作　　者：刘奇奇 吴润[2] LIU Qiqi;WU Run(Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking,Wuhan University of Science and Technology,Wuhan 430081,China;Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学钢铁冶金新工艺湖北省重点实验室,湖北武汉430081 [2]武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室,湖北武汉430081

出　　处：《热加工工艺》2023年第14期161-164,共4页Hot Working Technology

摘　　要：以Mn-V低合金钢为研究对象,对经不同热处理后冲击性能不合格的试样进行断口和组织分析,结果表明,热轧态魏氏组织和带状组织是造成材料冲击韧性不合格的主要原因,正火后消除了魏氏体组织和部分条带状组织,但由于冷速控制不当产生了大量的M/A岛块状组织,M/A岛与铁素体界面发生解理开裂,它破坏了基体的连续性,造成冲击韧性极低而易断裂。经920℃淬火+650℃回火的调质处理后,带状组织几乎完全消失,主要是多边形铁素体和回火索氏体,其韧性极高,改善了材料的冲击韧性。Mn-V low alloy steel is taken as the research object,and the fracture surface and microstructure of samples that are not qualified for impact properties after different heat treatments were analyzed.The results show that hot rolled widmanstatten structure and banded structure are the main reasons for unqualified impact toughness of materials.After normalizing,the widmanstatten structure and some banded structures are eliminated.However,due to the improper control of cooling rate,a large number of M/A island massive structures are produced and cleavage cracks occur at the interface between M/A island and ferrite,which destroy the continuity of the matrix and cause extremely low impact toughness.After quenching and tempering at 920℃and tempering at 650℃,the banded structure almost disappears,mainly polygonal ferrite and tempered sorbite,with high toughness,which improves the impact toughness of the material.

关 键 词：魏氏组织 带状组织 M/A岛 冲击韧性 

分 类 号：TG111.91[金属学及工艺—物理冶金] TG157[金属学及工艺—金属学]