Adverse effect of niobium and boron on hot deformation behavior of sulfur-containing steel  

作　　者：Guo-ning He Shi-qi Wan Bo Jiang Chao-lei Zhang Ya-zheng Liu Chun-jing Wu 

机构地区：[1]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing,100083,China [2]Institute for Advanced Materials and Technology,University of Science and Technology Beijing,Beijing,100083,China

出　　处：《Journal of Iron and Steel Research International》2024年第1期252-263,共12页

基　　金：The authors appreciate the financial support from Xining Special Steel Co.,Ltd.and student research training project of University of Science and Technology Beijing.

摘　　要：The hot deformation behaviors of sulfur-containing gear steel 20MnCr5 containing three different contents of Nb and B(0,0.021%Nb,and 0.024%Nb-0.0022%B)were investigated.Hot compression and tenssion tests were carried out by Gleeble3800 at the austenite region from 850 to 1150℃and the adverse effects of Nb and B were analyzed by the fracture,microstructure and precipitate observations.Hot compression tests showed that the proportions of instable area in hot processing maps of 0.021%Nb and Nb-B steels were higher and the deformability of Nb free steel was better.The tensile deformation experiments showed that the reduction areas of Nb free,0.021%Nb and Nb-B steels were 92%-99%,84%-98%and 67%-97%,respectively.The addition of Nb or Nb and B inhibited the dynamic recrystallization during hot deformation,and consequently,more deformed grains were then formed in 0.021%Nb and Nb-B steels thus to obtain the microstructure with worse uniformity and then deteriorate the deformability.In addition,the interaction between inclusions and microalloyed elements was also significant.NbC particles of 0.021%Nb and Nb-B steels dynamically precipitated during deformation and precipitated together with MnS thus to worsen the deformability,resulting in the decrease of reduction area.

关 键 词：Hot deformation Gear steel Processing map Dynamic recrystallization MICROALLOYING 

分 类 号：TG142[一般工业技术—材料科学与工程]