西安不锈钢板材拉深过程中开裂原因

摘要：<p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">西安</span></span><span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">不锈钢板材拉深过程中开裂原因</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">拉伸奥氏体不锈钢板材有时会出现开裂现象，而且每个现象不太一样。</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">有的是拉伸变形之后开裂；有的是从凹模内退出时就立马开裂；有的是拉伸变形之后受到撞击或振动时开裂；也有的是拉伸变形过后存放一段时间或使用过程中突然开裂。</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">其实开裂原因主要是因为奥氏体不锈钢板材的延展性比较低、弹性模量</span>E<span style="font-family:宋体;">有点大，硬化指数比较高，而且从屈服到开裂的塑性变形阶段比较短。</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">奥氏体不锈钢的冷作硬化指数相对比较高，而且是亚稳定型不锈钢，在变形时会发生相变，形成马氏体组织。马氏体相性比较脆，所以容易会开裂。在塑性变形时，随着奥氏体相变形量的增大，诱发的马氏体相含量也会随着变形量的增大而增多，残余应力也就越高。从而形成恶性循环，在拉伸过程中奥氏体不锈钢板材也就越容易出现开裂现象。</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">其实在奥氏体不锈钢板材的拉伸过程中还可以采取下列预防措施：</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">可以在凹、凸模之间涂上润滑剂，产生一层具备一定的韧性和延展性的薄膜，这对奥氏体不锈钢板材的拉伸效果明显。</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">可以采用白口铸铁作为压边圈磨具，锥形压边圈也可以使用，因为白口铸铁的存油性能比较好，极易产生润滑油膜。</span></span> </p> <p style="margin:0pt;"> <span style="font-family:宋体;font-size:10.5pt;mso-spacerun:"yes";mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:"Times New Roman";mso-font-kerning:1.0000pt;"><span style="font-family:宋体;">把奥氏体不锈钢板材的边缘加工光滑些，不能有微裂缺口，这样有效避免开裂。</span></span> </p>