铬和铝元素对低碳贝氏体钢组织和性能影响  

Effect of Cr and Al on microstructure and properties of low carbon bainitic steels

作　　者：姚耔杉 胡海江[1] 田俊羽 周明星[1] 徐光[1] YAO Zi-shan;HU Hai jiang;TIAN Jun-yu;ZHOU Ming xing;XU Guang(The State Key Laboratory of Refractories and Metallurgy.Wuhan University of Science and Technology.W uhan 430081.Hubei,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

出　　处：《钢铁》2020年第12期66-71,80,共7页Iron and Steel

基　　金：国家自然科学基金青年基金资助项目(51704217);湖北省技术创新专项重大资助项目(2017AAA116)。

摘　　要：低碳贝氏体钢通常需要添加一定量合金元素来提升性能,为了研究合金元素铬和铝在低碳贝氏体钢中的作用,以Fe-C-Si-Mn-Mo系贝氏体钢为基础,设计了单独添加铬元素和复合添加Cr+Al元素的3种低碳贝氏体钢,研究了铬和铝的添加对连续冷却处理低碳贝氏体钢显微组织、力学性能及贝氏体相变的影响规律。结果表明,连续冷却条件下,铬可以促进低碳贝氏体钢相变趋向于更低的温度区间进行,细化贝氏体组织,从而提高强度;铝可以促进贝氏体相变动力学,但对低碳贝氏体钢意义不大。同时,添加铝会使低碳贝氏体钢组织粗化,导致强度和伸长率同时下降。综合来看,复合添加铬和铝的优化效果不如单独添加铬,单独添加铬的低碳贝氏体钢强度达到1623MPa,伸长率为10.5%,结果可以为低碳贝氏体钢成分设计提供依据。Low carbon bainitic steels usually require the addition of an appropriate amount of alloying elements to improve performance.In order to study the function of Cr and Al in bainitic steels,three steels with different addition of Cr and Al based on composition of Fe-C-Si-Mn-Mo were designed.The effects of Cr and Al addition on microstructure,mechanical property and bainitic transformation in low carbon bainitc steel during the continuous cooling treatment were investigated.The results show that Cr addition can drive the bainitic transformation to a lower temperature range during the continuous cooling process.The yield and tensile strength can be enhanced by adding Cr due to the refining bainitic microstructure.Although Al addition can accelerate the kinetics of bainitic transformation,that has little significance for low carbon bainitic steel.On the contrary,the addition of Al can coarsen the structure of low carbon bainite steel,resulting in the decrease of strength and elongation.In summary,the strength of low carbon Cr-addition bainitic steel is high as 1623 MPa with a considerable elongation of 10.5%.The optimization effect of Cr addition is significantly better than the composite addition of Cr and Al.The results can provide basis for the composition design of low carbon bainitic steel.

关 键 词：贝氏体 合金元素 组织 性能 等温转变 

分 类 号：TG142.1[一般工业技术—材料科学与工程]