热轧60Si2Mn带钢的脆断特征及断裂行为  

Brittle fracture characteristics and fracture behavior of hot rolled 60Si2Mn strip steel

作　　者：田亚强 么志强 年保国 张晓磊 薛启河 宋进英 张明山 陈连生 Tian Yaqiang;Yao Zhiqiang;Nian Baoguo;Zhang Xiaolei;Xue Qihe;Song Jinying;Zhang Mingshan;Chen Liansheng(Key Laboratory of the Ministry of Education for Modern Metallurgy Technology,North China University of Science and Technology,Tangshan Hebei 063210,China;HBIS Material Technology Research Institute,Shijiazhuang Hebei 050023,China;Chengde Vanadium Titanium New Material Co.,Ltd.,Chengde Hebei 067102,China)

机构地区：[1]华北理工大学现代冶金技术教育部重点实验室,河北唐山063210 [2]河钢材料技术研究院,河北石家庄050023 [3]承德钒钛新材料有限公司,河北承德067102

出　　处：《金属热处理》2024年第8期281-288,共8页Heat Treatment of Metals

摘　　要：利用光学显微镜、扫描电镜和电子拉伸试验机等分析了某厂热轧60Si2Mn带钢脆断缺陷试样的脱碳、夹杂物、偏析和脆断断口等,表征了脆断处与远离断口处的显微组织和力学性能,并对热轧60Si2Mn带钢脆断特征及断裂行为进行了探究。结果表明,脆断处无明显的脱碳、夹杂物和偏析存在,断口呈现脆性断裂。脆断处与远离断口处试样的组织中先共析铁素体含量分别为12.45%和0.66%,珠光体片层间距分别为578和236 nm。60Si2Mn带钢热轧板脆断的主要诱因是脆断处相对远离断口处的先共析铁素体含量较多,珠光体片层间距较大,抵抗变形的能力差,容易在轧制过程中产生不均匀变形,并且粗大的铁素体与渗碳体片层间易产生应力差导致发生脆断,其裂纹沿两相界面进行扩展。然而细小的珠光体塑性变形较均匀,裂纹以穿过珠光体片层的方式进行扩展。Decarburization,inclusions,segregation and brittle fracture of hot rolled 60Si2Mn steel strip were analyzed by means of optical microscope,scanning electron microscope and electronic tensile testing machine.Microstructure and mechanical properties of the specimens near the brittle fracture and away from the fracture were characterized,and the brittle fracture characteristics and fracture behavior of hot rolled 60Si2Mn steel strip were investigated.The results show that there is no obvious decarburization,inclusion and segregation at the brittle fracture,and the fracture presents brittle fracture.The content of proeutectoid ferrite in the specimens near the brttle fracture and away from the fracture is 12.45%and 0.66%,respectively,and the pearlite lamellar spacing is 578 nm and 236 nm,respectively.The main cause of brittle fracture of hot rolled 60Si2Mn steel strip is that the content of proeutectoid ferrite in the brittle fracture is higher than that in the position away from the fracture,and the pearlite lamellar spacing is larger,which leads to poor resistance to deformation and is prone to uneven deformation during the rolling process.Additionally,the stress difference between the coarse ferrite and cementite layers can easily lead to brttle fracture,and the cracks propagate along the two-phase interface.However,the plastic deformation of fine pearlite is relatively uniform,and cracks propagate through the layers of pearlite.

关 键 词：热轧60Si2Mn钢 脆断 珠光体片层间距 力学性能 裂纹扩展 

分 类 号：TG142.1[一般工业技术—材料科学与工程]