组织性能不均匀性导致65Mn钢冷轧断带机理分析
Mechanism analysis of 65Mn steel strip breakage during cold rolling caused by inhomogeneity of microstructure and properties
田亚强 1么志强 1年保国 2张晓磊 3宋进英 1张明山 1陈连生1
作者信息
- 1. 华北理工大学教育部现代冶金技术重点实验室,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
- 折叠
摘要
针对65Mn钢热轧板在第一道次冷轧时出现断带问题,采用光学显微镜(OM)、扫描电镜(SEM)、拉伸以及硬度测试等手段,对缺陷板的组织及性能进行分析.结果表明,65Mn钢断带板晶粒尺寸粗大,沿横向分布不均,边部至1/2处晶粒度由6.0级降到4.5级,原始奥氏体晶粒度由5.5级降为4.0级;珠光体片层间距由759.0 nm增加到1128.0 nm,珠光体球团尺寸由26.1 μm增加到31.3 μm;力学性能横向分布也不均匀,边部至1/2处的屈服强度由541 MPa降为529 MPa,抗拉强度由669 MPa降为651 MPa,伸长率由9.6％提高到11.7％,硬度由65.0 HRB降到62.2 HRB.65Mn钢断带板由于组织及晶粒不均匀,在受到外应力时,变形不协调,最终导致断带缺陷的发生.经优化热轧工艺处理后,65Mn钢冷轧开裂、断带等塑韧性缺陷发生率降至0.15％以下.
Abstract
Microstructure and mechanical properties of 65Mn steel hot-rolled plate with strip breakage during the first cold-rolling were analyzed by means of optical microscope(OM),scanning electron microscope(SEM),tensile and hardness tests.The results show that the grain of 65Mn steel strip breakage plate is coarse and unevenly distributed along the transverse direction.The grain size coarsens from grade 6.0 to 4.5 at the edge to 1/2 of the strip breakage plate,and the prior austenite grain size coarsens from grade 5.5 to 4.0.The lamellar spacing of pearlite increases from 759.0 nm to 1128.0 nm,and the pearlite colony size increases from 26.1 μm to 31.3 μm.The transverse distribution of mechanical properties is also uneven.From the edge to 1/2 of the cold-rolled plate,the yield strength decreases from 541 MPa to 529 MPa,and the tensile strength decreases from 669 MPa to 651 MPa.The elongation increases from 9.6％to 11.7％,and the hardness decreases from 65.0 HRB to 62.2 HRB.When subjected to external stress,the deformation of 65Mn steel strip breakage plate is not coordinated due to the uneven microstructure and grains,which eventually leads to the occurrence of strip breakage defect.The incidence of plastic and toughness defects such as cold rolling cracking and strip breakage of the 65 Mn steel is reduced to less than 0.15％after optimizing the hot rolling process.
关键词
65/Mn钢/断带/晶粒度/珠光体/变形不协调Key words
65Mn steel/strip breakage/grain size/pearlite/uncoordinated deformation引用本文复制引用
出版年
2024
NETL
NSTL
万方数据