摘要：<span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">不銹鋼焊接性能的主要表現(xiàn)</span></span> </p> <span style="font-family:宋體;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:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">高溫裂紋</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在這里所說的高溫裂紋是指與焊接有關(guān)的裂紋。高溫裂紋可大致分為凝固裂紋、顯微裂紋、</span><span style="font-family:'Times New Roman';"><span lang="EN-US">HAZ(</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">熱影響區(qū)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">裂紋和再加熱裂紋等。</span></span> </p> <span style="font-family:宋體;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:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">低溫裂紋</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">在馬氏體型不銹鋼和部分具有馬氏體組織的鐵素體型不銹鋼中有時會發(fā)生低溫裂紋。由于其產(chǎn)生的主要原因是氫擴散、焊接接頭的約束程度以及其中的硬化組織，所以解決方法主要是在焊接過程中減少氫的擴散，適宜地進行預(yù)熱和焊后熱處理以及減輕約束</span></span><span style="font-family:'Times New Roman';font-size:small;"> </span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;"><span style="font-size:small;">程度。</span></span> </p> <span style="font-family:宋體;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:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">焊接接頭的韌性</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在奧氏體型不銹鋼中為減輕高溫裂紋敏感性，在成分設(shè)計上通常使其中殘存有</span><span style="font-family:'Times New Roman';"><span lang="EN-US">5% -io%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">的鐵素體。但這些鐵素體的存在導(dǎo)致了低溫韌性的下降，在雙相不銹鋼進行焊接時，焊接接頭區(qū)域的奧氏體量減少而對韌性產(chǎn)生影響。另外隨著其中鐵素體的增加，其韌性值有顯著下降的趨勢</span><span lang="EN-US"><span style="font-family:'Times New Roman';">.</span></span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">已證實高純鐵素體型不銹鋼的焊接接頭的韌性顯著下降的原因是由于混入碳，氮、氧的緣故。其中一些鋼的焊接接頭中的氧含量增加后生成了氯化物型夾雜，這些夾雜物成為裂紋發(fā)生源或裂紋傳播的途徑使得韌性下降</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">而有一些鋼則是由于在保護氣體中混人了空氣，其中的氨含量增加在基體解理面</span><span style="font-family:'Times New Roman';"><span lang="EN-US">{100}</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">面上產(chǎn)生板條狀</span><span style="font-family:'Times New Roman';"><span lang="EN-US">Cr2 N</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，基體變硬而使得韌性下降。</span></span> </p> <span style="font-family:宋體;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">(4)b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相脆化</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奧氏體型不銹銅、鐵素體不銹鋼和雙相不銹鋼易發(fā)生</span><span style="font-family:'Times New Roman';"><span lang="EN-US">b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相脆化，由于組織中析出了百分之幾的</span><span style="font-family:'Times New Roman';"><span lang="EN-US">b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相，韌性顯著下降。</span><span style="font-family:'Times New Roman';"><span lang="EN-US">o</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相一般是在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">600</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">～</span><span style="font-family:'Times New Roman';"><span lang="EN-US">900</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">范圍內(nèi)析出，尤其在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">750</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">左右*易析出。作為防止</span><span style="font-family:'Times New Roman';"><span lang="EN-US">b</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">相產(chǎn)生的預(yù)防型措，</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奧氏體型不銹鋼中應(yīng)盡量減少鐵索體的含量。</span></span> </p> <span style="font-family:宋體;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">(5) 475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆化</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">鉻含量在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">15. 5%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以上的不銹鋼，在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">附近</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(370 -540</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">，長時間受熱時，常會出現(xiàn)鋼的強度升高，韌性性大幅度降低</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">并且伴隨著耐蝕性的降低。由于這一現(xiàn)象多見于加熱溫度在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">。</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">左右，因此被稱作</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆性。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">由于不銹鋼的鉻含量大多在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">15. 5%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以上，焊接時的焊接熱也一定會經(jīng)過</span><span style="font-family:'Times New Roman';"><span lang="EN-US">370</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">～</span><span style="font-family:'Times New Roman';"><span lang="EN-US">540</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">這個區(qū)間，如果焊接時控制不當(dāng)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">370</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">～</span><span style="font-family:'Times New Roman';"><span lang="EN-US">540</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">這個區(qū)間停留時間過長，在一些鉻含量較高的馬氏體不銹鋼奧氏體不銹鋼、鐵素體不銹鋼、雙相不銹鋼以及沉淀硬化不銹鋼都會出現(xiàn)</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆化。系統(tǒng)的研究指出</span><span style="font-family:'Times New Roman';"><span lang="EN-US">475</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">脆化處理后，鋼不僅有冷脆性，還有熱脆性</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(800</span></span><span style="font-family:宋體;mso-bidi-font-family:宋體;">℃</span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以下的沖擊韌性比未脆化低</span><span style="font-family:'Times New Roman';"><span lang="EN-US">)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">。脆化程度隨鉻量的增加而增大，鉻含量在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">15. 5%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">以下</span><span style="font-family:'Times New Roman';"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">則無脆化趨勢。碳含量在</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0. 04%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">～</span><span style="font-family:'Times New Roman';"><span lang="EN-US">0. 28%</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">范圍內(nèi)，脆化程度沒有明顯的區(qū)別。</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span> <p style="margin:0cm 0cm 0pt;"> <span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">奧氏體和鐵素體型不銹鋼的可焊性較好。馬氏體型不銹鋼，可焊性差，但馬氏體型不銹鋼中的低碳馬氏體不銹鋼和低碳鉻一鎳一鉬系</span><span style="font-family:'Times New Roman';"><span lang="EN-US">(</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">超級</span><span style="font-family:'Times New Roman';"><span lang="EN-US">)</span></span><span style="font-family:宋體;mso-ascii-font-family:&quot;Times New Roman&quot;;mso-hansi-font-family:&quot;Times New Roman&quot;;">馬氏體不銹鋼，在采取一定的工藝、技術(shù)措施后，還是可以獲得較為滿意的焊接效果</span></span> </p> <span style="font-family:宋體;font-size:small;"> </span>