304不锈钢角钢拉深会出现哪些问题？

摘要：<span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢拉深会出现哪些问题？</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢的延展率小、弹性模量</span><span style="font-family:"Times New Roman";"><span lang="EN-US">E</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">较大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">硬化指数较高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">厚向异性指数</span><span style="font-family:"Times New Roman";"><span lang="EN-US">r</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">值很小</span><span style="font-family:"Times New Roman";"><span lang="EN-US">(304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢为</span><span style="font-family:"Times New Roman";"><span lang="EN-US">0.9~0.11,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">软钢为</span><span style="font-family:"Times New Roman";"><span lang="EN-US">1.3~2.0).304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢材料由屈服到破裂的塑性变形阶段短</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">特别是它的塑性应变比的加权值</span><span style="font-family:"Times New Roman";"><span lang="EN-US">R</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">较大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢板拉深开裂有时发生在拉深变形之后</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">有时是在当拉深件由凹模内退出时立即发生</span><span style="font-family:"Times New Roman";"><span lang="EN-US">;</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">有时是在拉深变形后受撞击或振动时发生</span><span style="font-family:"Times New Roman";"><span lang="EN-US">;</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">也有时在拉深变形后经过一段时间的存放或在使用过程中才发生</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">本文针对</span><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢板拉深时产生缺陷的原因进行了分析</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">并提出解决措施</span><span lang="EN-US"><span style="font-family:"Times New Roman";">.</span></span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">1</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、机械性能检验</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">(1)</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">检验方法：</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">a.</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">拉伸试验方法。常用的标准检验方法有</span><span style="font-family:"Times New Roman";"><span lang="EN-US">GB/T228-87</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2201</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2241</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">ASTM A370</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">DIN50145</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">等</span><span lang="EN-US"><span style="font-family:"Times New Roman";">;</span></span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">b.</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">弯曲试验方法。常用的标准检验方法有</span><span style="font-family:"Times New Roman";"><span lang="EN-US">GB/T232-88</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2204</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2248</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">ASTM E290</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">DIN50111</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">等。</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">(2)</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">性能指标：考核不锈钢扁钢性能的检验项目主要为拉伸试验和弯曲试验。指标包括屈服点、抗拉强度、延伸率及弯曲合格等项。</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">2</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、开裂形成的原因</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">奥氏体</span><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢的冷作硬化指数高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">(304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢为</span><span style="font-family:"Times New Roman";"><span lang="EN-US">0.34).</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">奥氏体</span><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢为亚稳定型</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">在变形时会发生相变</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">诱发马氏体相</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">马氏体相较脆</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">因此容易发生开裂</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">在塑性变形时</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">随着变形量的增大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">诱发的马氏体含量也将随着变形量的增大而增高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">残余应力也越大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">残余应力与马氏体含量的关系</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">诱发的马氏体相含量越高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">引起的残余应力也越大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">在加工过程中也就越易开裂</span><span lang="EN-US"><span style="font-family:"Times New Roman";">.</span></span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">3</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、表面划痕形成的原因</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢拉深件表面出现划痕主要是由于工件和模具表面存在相对移动</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">在一定压力的作用下</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">致使坯料与模具局部表面直接产生摩擦</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">加之坯料的变形热使坯料及金属屑熔敷在模具表面上</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">使工件表面擦伤产生划痕</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";"><span style="font-size:small;">进出口不锈钢角钢的定货一般以使用中所要求的规格为主，其钢号为相应的碳结钢钢号。也即不锈钢角钢除了规格号之外，没有特定的成分和性能系列。</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">不锈钢角钢的交货长度分定尺、倍尺两种，国产不锈钢角钢的定尺选择范围根据规格号的不同有</span><span style="font-family:"Times New Roman";"><span lang="EN-US">3—9m</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">4—12m</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">4—19m</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">6—19m</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">四个范围。日本产不锈钢角钢的长度选择范围为</span><span style="font-family:"Times New Roman";"><span lang="EN-US">6—15m</span></span><span style="font-family:宋体;mso-ascii-font-family:"mso-hansi-font-family:";">。</span></span> </p> <span style="font-family:宋体;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span lang="EN-US"><span style="font-family:"Times New Roman";font-size:small;"> </span></span> </p> <span style="font-family:宋体;font-size:small;"> </span>