幾乎所有的焊接方法都可以用于焊接不銹鋼,不過因不(bu)銹鋼種(zhong)類的不同而有所不同。目前常用的不銹鋼熔化焊方法包括手工電弧焊、埋弧自動焊、鎢極惰性氣體保護焊、熔化極氣體保護焊、等離子(zi)弧焊等,另外,電子束焊和激光焊有時也被采用。
1. 手工電弧焊
手(shou)工(gong)(gong)電(dian)弧焊(han)(han)(han)(han)(han)是(shi)用(yong)(yong)手(shou)工(gong)(gong)操(cao)作(zuo)(zuo)電(dian)焊(han)(han)(han)(han)(han)條進行焊(han)(han)(han)(han)(han)接(jie)的(de)(de)一種焊(han)(han)(han)(han)(han)接(jie)方法。手(shou)工(gong)(gong)電(dian)弧焊(han)(han)(han)(han)(han)時(shi),利用(yong)(yong)焊(han)(han)(han)(han)(han)條和工(gong)(gong)件之間產生電(dian)弧將焊(han)(han)(han)(han)(han)條和工(gong)(gong)件局部加熱到熔(rong)化(hua)狀態,焊(han)(han)(han)(han)(han)條端部熔(rong)化(hua)后的(de)(de)熔(rong)滴和熔(rong)化(hua)的(de)(de)母材(cai)融合在一起形成(cheng)熔(rong)池,隨著電(dian)弧向前移動,熔(rong)池液(ye)態金(jin)屬(shu)逐步冷卻結(jie)晶形成(cheng)焊(han)(han)(han)(han)(han)縫(feng)。不(bu)(bu)銹鋼的(de)(de)手(shou)工(gong)(gong)電(dian)弧焊(han)(han)(han)(han)(han),應用(yong)(yong)最(zui)為廣(guang)泛,可用(yong)(yong)于(yu)(yu)各類(lei)不(bu)(bu)銹鋼的(de)(de)焊(han)(han)(han)(han)(han)接(jie)。其(qi)特點是(shi)手(shou)工(gong)(gong)電(dian)弧焊(han)(han)(han)(han)(han)的(de)(de)熱影響區較小,易于(yu)(yu)保證質量,設(she)備簡單,操(cao)作(zuo)(zuo)靈活,適應各種焊(han)(han)(han)(han)(han)接(jie)位(wei)置與(yu)不(bu)(bu)同板厚的(de)(de)工(gong)(gong)藝要求(qiu)。現在,不(bu)(bu)銹鋼焊(han)(han)(han)(han)(han)條也基本能夠(gou)滿足各類(lei)不(bu)(bu)銹鋼的(de)(de)焊(han)(han)(han)(han)(han)接(jie)要求(qiu),在焊(han)(han)(han)(han)(han)條選用(yong)(yong)上(shang)幾乎不(bu)(bu)受(shou)限制。
缺點是生產效率低(di);勞(lao)動(dong)條件(jian)差;對(dui)焊工(gong)的(de)要(yao)(yao)求較(jiao)高(gao),在許多場合下,焊工(gong)必須(xu)具備(bei)相當的(de)資格(ge);有(you)些材料(liao)的(de)焊條熔敷金屬還達不(bu)到使用要(yao)(yao)求,如超(chao)高(gao)純(chun)不(bu)銹鋼;工(gong)件(jian)厚(hou)度一般在1mm以(yi)下的(de)薄板(ban)不(bu)適于手工(gong)電弧焊。
2. 埋(mai)弧(hu)自動焊
埋弧(hu)自(zi)動焊(han)(han)是將焊(han)(han)接(jie)電弧(hu)用一層顆(ke)粒狀的(de)可(ke)(ke)熔(rong)(rong)(rong)化(hua)焊(han)(han)劑覆蓋在下面(mian),電弧(hu)光不外露的(de)一種焊(han)(han)接(jie)方法。目前主(zhu)要用于奧氏體(ti)不銹(xiu)鋼中厚板的(de)焊(han)(han)接(jie),其特點是焊(han)(han)接(jie)電流大(da),熔(rong)(rong)(rong)深大(da),工件的(de)坡口可(ke)(ke)較小;焊(han)(han)接(jie)速度快(kuai),生產效率高;焊(han)(han)縫(feng)(feng)金(jin)屬凝固較慢,液(ye)體(ti)金(jin)屬與熔(rong)(rong)(rong)化(hua)的(de)焊(han)(han)劑間有較多的(de)時間進行冶金(jin)反應,減少了焊(han)(han)縫(feng)(feng)中產生氣孔(kong)的(de)可(ke)(ke)能性;焊(han)(han)縫(feng)(feng)成(cheng)型美(mei)觀,工作(zuo)環境好,操(cao)作(zuo)容易,對(dui)焊(han)(han)工的(de)要求(qiu)相對(dui)簡單。
缺(que)點是焊(han)接熱輸人量(liang)大,熱影響(xiang)區寬大,焊(han)縫(feng)組織粗大;選材時要特別考慮到(dao)焊(han)絲與焊(han)劑的配(pei)合;焊(han)接位(wei)置只(zhi)能是平焊(han)位(wei)置;不能直接觀(guan)察電弧與坡(po)口的相對位(wei)置,必須有自(zi)動跟(gen)蹤裝置。
3. 鎢極惰性氣體保護(hu)電焊
鎢(wu)極(ji)惰(duo)性(xing)氣體保(bao)護焊(han)(han)(英文簡稱TIG焊(han)(han))可分為手(shou)工焊(han)(han)、半自動(dong)焊(han)(han)和(he)(he)自動(dong)焊(han)(han)三(san)種。TIG焊(han)(han)中的鎢(wu)極(ji)氬弧焊(han)(han)在不銹鋼中應(ying)用相當(dang)普(pu)遍(bian)。它適應(ying)于(yu)全位置焊(han)(han)接(jie),一般不產生飛(fei)濺,焊(han)(han)縫成形美(mei)觀。特(te)別適應(ying)薄件的焊(han)(han)接(jie),在許(xu)多厚件的坡口(kou)焊(han)(han)接(jie)時,常用TIG打底,避免了手(shou)工電弧焊(han)(han)易(yi)產生裂紋和(he)(he)清渣困難(nan)的缺點。惰(duo)性(xing)氣體能有效(xiao)地隔(ge)絕空氣,它本身又不溶于(yu)金屬,不和(he)(he)金屬反應(ying),能保(bao)證不銹鋼的化學成分要求。
缺點是熔(rong)深淺,熔(rong)敷速度(du)小,生產效(xiao)率低(di),生產成本較高。
4. 熔化極氣體保護焊
熔(rong)(rong)(rong)化(hua)(hua)極氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)護(hu)弧焊(han)(han)(han)(han)(han)(GMAW)采(cai)用可(ke)熔(rong)(rong)(rong)化(hua)(hua)的(de)焊(han)(han)(han)(han)(han)絲(si)與(yu)被焊(han)(han)(han)(han)(han)工件之間的(de)電弧作為(wei)熱(re)源來熔(rong)(rong)(rong)化(hua)(hua)焊(han)(han)(han)(han)(han)絲(si)和母材金屬(shu)(shu),并向(xiang)焊(han)(han)(han)(han)(han)接區輸(shu)送保(bao)(bao)護(hu)氣(qi)(qi)(qi)體(ti)(ti),使電弧、熔(rong)(rong)(rong)化(hua)(hua)的(de)焊(han)(han)(han)(han)(han)絲(si)、熔(rong)(rong)(rong)池(chi)及(ji)附近的(de)母材金屬(shu)(shu)免受周圍空(kong)氣(qi)(qi)(qi)的(de)侵(qin)害。連續送進的(de)焊(han)(han)(han)(han)(han)絲(si)金屬(shu)(shu)不(bu)斷(duan)熔(rong)(rong)(rong)化(hua)(hua)并過渡到熔(rong)(rong)(rong)池(chi),與(yu)熔(rong)(rong)(rong)化(hua)(hua)的(de)母材金屬(shu)(shu)融合形(xing)成(cheng),式體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)又分(fen)為(wei)熔(rong)(rong)(rong)化(hua)(hua)極惰(duo)性(xing)氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)化(hua)(hua)極氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)可(ke)自動(dong)焊(han)(han)(han)(han)(han),也可(ke)半自動(dong)好(hao)。化(hua)(hua)極氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)又分(fen)為(wei)熔(rong)(rong)(rong)化(hua)(hua)極惰(duo)性(xing)氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)(MIG)、熔(rong)(rong)(rong)化(hua)(hua)極氧化(hua)(hua)性(xing)混合平自動(dong)樣(MAG)、二氧化(hua)(hua)碳氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)和藥芯(xin)焊(han)(han)(han)(han)(han)絲(si)氣(qi)(qi)(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)。
熔(rong)化極(ji)惰性(xing)氣(qi)(qi)體保護焊(MIG)在(zai)不銹(xiu)鋼(gang)的焊接中應(ying)用較(jiao)為(wei)普(pu)遍,通常(chang)采用惰性(xing)氣(qi)(qi)體的氬、氦或它們的混(hun)合氣(qi)(qi)體作為(wei)焊接區(qu)的保護氣(qi)(qi)體,由于焊絲外表(biao)沒有(you)涂料層,電流可(ke)大(da)大(da)提高(gao),因而(er)母(mu)材熔(rong)深大(da),焊絲熔(rong)化速度(du)快,熔(rong)敷率高(gao),與鎢極(ji)氬弧焊相比(bi),可(ke)大(da)大(da)提高(gao)生生產(chan)效(xiao)率。尤其適用于中厚板的焊接。
5. 等(deng)離子弧焊(han)
等(deng)(deng)離子(zi)(zi)弧是(shi)一種壓(ya)縮電弧,由于弧斷面被壓(ya)縮較小,因而能量集中、溫度高、焰流速度大,因此(ci)等(deng)(deng)離子(zi)(zi)弧焊在一定母材厚度范圍內(nei)能充分(fen)熔透,尤(you)其適合不銹鋼鋼管縱(zong)縫(feng)的焊接。等(deng)(deng)離子(zi)(zi)弧焊的焊接速度較TIG焊快,電弧挺(ting)直(zhi)性好,熱影響(xiang)區小,能夠焊接很薄的工件,最薄可達0.025mm。
缺點是設備價格昂貴(gui),工藝參數的(de)(de)調節匹(pi)配復雜,目前的(de)(de)噴(pen)嘴壽(shou)命還較短(duan),這些都(dou)使等離子弧焊(han)的(de)(de)應用受到限(xian)制。