杂质元素Sn对C-Mn钢焊接热影响区脆性的影响  

Influence of Impurity Element Sn on Brittleness of Welding Heat Affected Zone of C-Mn Steel

作　　者：陈浩杰[1] 石磊 CHEN Haojie;SHI Lei(Department of Architecture Engineering,Luzhou Vocational and Technical College,Luzhou 646600,China;College of Material and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]泸州职业技术学院建筑工程系,四川泸州646600 [2]武汉科技大学材料与冶金学院,湖北武汉430081

出　　处：《热加工工艺》2018年第15期199-203,共5页Hot Working Technology

摘　　要：对装配式钢结构用C-Mn和C-Mn-Sn钢进行了焊接热模拟试验,研究了不同焊接线能量下Sn元素对钢结构用钢显微组织、物相组成和韧-脆转变温度的影响,并分析了Sn的晶界偏聚行为及其对焊接接头热影响区脆化作用的影响。结果表明,C-Mn和C-Mn-Sn钢的韧-脆转变温度会随着焊接线能量的增加先增大后减小;当焊接线能量为36 k J/cm时,Sn对焊接热影响区起到了明显的脆化作用,而在焊接线能量为60 k J/cm和100 k J/cm时,Sn的存在并没有使焊接热影响区明显脆化;当焊接线能量为36 k J/cm时,C-Mn-Sn钢中Sn的晶界浓度测量值为0.24at%,Sn晶界浓度修正值为0.77at%;焊接线能量为60 k J/cm和100 k J/cm时,C-Mn-Sn钢中晶界的破坏使得由晶界偏聚和晶界Sn偏聚引起的脆化作用消失;在三种焊接线能量下,含Sn的C-Mn-Sn钢的显微硬度都要小于不含Sn的C-Mn钢。The welding thermal simulation test of C-Mn and C-Mn-Sn steels used for fabricated steel structure was carried out, the effect of Sn element on the microstructure, phase composition and ductile brittle transition temperature of steel used for construction was studied under different welding line energies, and the grain boundary segregation behavior of Sn and its effect on the embrittlement of the heat affected zone of welded joints were analyzed. The results show that the ductile brittle transition temperature of C-Mn and C-Mn-Sn steels increases at first and then decreases with the increase of the welding line energy. When the welding line energy is 36 k J/cm, Sn has clear embrittlement effect on the heat affected zone, and the existence of Sn does not make the heat affected zone obviously brittle when the welding line energy is 60 k J/cm and 100 k J/cm. When the welding line energy is 36 k J/cm, the measured grain boundary concentration of Sn in C-Mn-Sn steel is0.24 at%, and the modified value of grain boundary concentration of Sn is 0.77 at%. When the welding line energy is 60 k J/cm and 100 k J/cm, the damage of grain boundary in C-Mn-Sn steel makes the embrittlement caused by grain boundary segregation and Sn segregation at the grain boundaries disappear. Under the three kinds of welding line energy, the microhardness of C-Mn-Sn steel containing Sn is less than that of C-Mn Sn steel.

关 键 词：杂质元素Sn C-MN钢 热影响区 脆化 显微组织 

分 类 号：TG401[金属学及工艺—焊接]