进口需要注意的问题

摘要：<p class="MsoNormal"> 西安<span style="font-family:宋体;">不锈钢</span>板<span style="font-family:宋体;">进口需要注意的问题</span> <o:p></o:p> </p> <p class="MsoNormal"> 西安<span style="font-family:宋体;">不锈钢</span>板<span style="font-family:宋体;">进口使用的不锈钢材料分进口与国产两种，国产材料，由于使用的是欧洲（</span>ISO<span style="font-family:宋体;">）体系，用成分表示，比较直观，不容易发生问题，现在我们重点谈谈进口不锈钢的一些需要注意的问题： </span><br /> 西安<span style="font-family:宋体;">不锈钢</span>板<span style="font-family:宋体;">进口材料标准</span> <br /> <span style="font-family:宋体;">现在，我们经常见到的进口不锈钢标准有美国</span>ASME<span style="font-family:宋体;">标准的</span><span style="font-family:'Times New Roman';">SA240</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">ASTM</span><span style="font-family:宋体;">标准的</span><span style="font-family:'Times New Roman';">A240</span><span style="font-family:宋体;">以及日本</span><span style="font-family:'Times New Roman';">JIS</span><span style="font-family:宋体;">标准的</span><span style="font-family:'Times New Roman';">SUS</span><span style="font-family:宋体;">；经常使用的牌号为</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">316L</span><span style="font-family:宋体;">等。下面以</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">为例来说明它们的表示方法：</span><span style="font-family:'Times New Roman';">JIS</span><span style="font-family:宋体;">标准中材料，表示比较简单，就是</span><span style="font-family:'Times New Roman';">SUS304</span><span style="font-family:宋体;">这样表示；</span><span style="font-family:'Times New Roman';">ASME</span><span style="font-family:宋体;">及</span><span style="font-family:'Times New Roman';">ASTM</span><span style="font-family:宋体;">的表示有几种：</span><span style="font-family:'Times New Roman';">SA240-304</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">SA240TP304</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">A240-304</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">A240TP304</span><span style="font-family:宋体;">，实际上，中间加</span><span style="font-family:'Times New Roman';">-</span><span style="font-family:宋体;">与加</span><span style="font-family:'Times New Roman';">TP</span><span style="font-family:宋体;">的意思是一样的。我们提到前面有</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">的材料，其中</span><span style="font-family:'Times New Roman';">L</span><span style="font-family:宋体;">为后缀，表示含碳量较低；经常可以看到的还有</span><span style="font-family:'Times New Roman';">H</span><span style="font-family:宋体;">，表示含碳量较高，主要使用在温度较高的场合；另外常见的还有</span><span style="font-family:'Times New Roman';">N</span><span style="font-family:宋体;">，表示加元素</span><span style="font-family:'Times New Roman';">N</span><span style="font-family:宋体;">，提高强度。有时候，我们还可以在后面见到：</span><span style="font-family:'Times New Roman';">2B</span><span style="font-family:宋体;">，</span><span style="font-family:'Times New Roman';">No.1</span><span style="font-family:宋体;">等后缀，这些后缀表示的是材料的表面状态；</span><span style="font-family:'Times New Roman';">2B</span><span style="font-family:宋体;">表示热轧加冷轧后，表面较好，达到镜面要求的</span><span style="font-family:宋体;">钢板</span><span style="font-family:宋体;">；</span>2D<span style="font-family:宋体;">表示热轧加冷轧后，表面一般的钢板；</span><span style="font-family:'Times New Roman';">No.1</span><span style="font-family:宋体;">表示热轧表面。 </span><br /> 西安<span style="font-family:宋体;">不锈钢</span>板<span style="font-family:宋体;">进口关于材料的代用</span> <o:p></o:p> </p> <p class="MsoNormal"> <span style="font-family:宋体;">在许多人心目中，材料</span><span style="font-family:'Times New Roman';">“</span><span style="font-family:宋体;">以高代低、以厚代薄</span><span style="font-family:'Times New Roman';">”</span><span style="font-family:宋体;">是天经地义的事情，不需要多管，实际上这种观点是错误的，下面我们以</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">、</span><span style="font-family:'Times New Roman';">304H</span><span style="font-family:宋体;">为例来进行说明：一般来看，</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">比</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">有更低的含碳量，更好的耐腐蚀性，因此可以代替</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">材料使用。确实</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">满足</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">的要求，而且比</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">更好，好像可以自动替代</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">，但从力学性能看，</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">的强度比</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">高，当按</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">设计时，用</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">替代，就会造成强度不够；另外，在我国压力容器标准</span><span style="font-family:'Times New Roman';">GB150-1998</span><span style="font-family:宋体;">中</span><span style="font-family:'Times New Roman';">4.1.6</span><span style="font-family:宋体;">条规定：奥氏体不锈钢的使用温度高于</span><span style="font-family:'Times New Roman';">525</span>℃<span style="font-family:宋体;">时，钢中含碳量应不小于</span>0.04%<span style="font-family:宋体;">。因此，认为</span><span style="font-family:'Times New Roman';">304L</span><span style="font-family:宋体;">可以代替</span><span style="font-family:'Times New Roman';">304</span><span style="font-family:宋体;">使用的观点是错误的，能不能使用与使用场合有关，而且按照容规规定，我们都没有权进行</span><span style="font-family:'Times New Roman';">“</span><span style="font-family:宋体;">材料代用</span><span style="font-family:'Times New Roman';">”</span><span style="font-family:宋体;">，只有原设计部门才可以有权进行</span><span style="font-family:'Times New Roman';">"</span><span style="font-family:宋体;">材料代用</span><span style="font-family:'Times New Roman';">"</span><span style="font-family:宋体;">的工作。</span><o:p></o:p> </p>