埋弧焊不銹鋼管焊接參數比焊條電弧焊多一些，包括焊接電流、電弧電壓、焊接速度、焊接材料、焊絲直徑、焊絲偏移量、焊絲干伸長度、焊絲輸送速度等。
①. 焊接電流
焊(han)(han)(han)(han)接(jie)(jie)電(dian)流(liu)的大小(xiao)直接(jie)(jie)影響焊(han)(han)(han)(han)接(jie)(jie)熔(rong)池(chi)的深(shen)淺(qian)，焊(han)(han)(han)(han)接(jie)(jie)電(dian)流(liu)大，熱輸入(ru)大、電(dian)弧挺度(du)大，焊(han)(han)(han)(han)接(jie)(jie)熔(rong)池(chi)深(shen)；反之(zhi)則(ze)淺(qian)。當焊(han)(han)(han)(han)接(jie)(jie)電(dian)流(liu)較大時(shi)，由于熔(rong)深(shen)較深(shen)，而焊(han)(han)(han)(han)縫(feng)寬(kuan)度(du)變化(hua)不大，所(suo)得到的焊(han)(han)(han)(han)縫(feng)成(cheng)形系數（焊(han)(han)(han)(han)縫(feng)的寬(kuan)度(du)與焊(han)(han)(han)(han)縫(feng)有(you)效厚度(du)的比(bi)值稱(cheng)為焊(han)(han)(han)(han)縫(feng)成(cheng)形系數）較小(xiao)。這樣(yang)的焊(han)(han)(han)(han)縫(feng)，對(dui)熔(rong)池(chi)中(zhong)氣(qi)體(ti)和(he)夾渣物的上(shang)浮(fu)和(he)溢(yi)出十分不利，易(yi)產生氣(qi)孔、夾渣和(he)熱裂紋。所(suo)以一(yi)般(ban)增(zeng)加電(dian)流(liu)時(shi)，必須相應的提(ti)高電(dian)弧電(dian)壓，以保(bao)證得到合理的焊(han)(han)(han)(han)縫(feng)形狀(zhuang)，一(yi)般(ban)焊(han)(han)(han)(han)縫(feng)成(cheng)形系數控(kong)制在(zai)1.3～2.0之(zhi)間，這樣(yang)對(dui)熔(rong)池(chi)中(zhong)的氣(qi)體(ti)溢(yi)出以及(ji)防(fang)止產生夾渣或熱裂紋等缺陷有(you)利。
②. 電(dian)弧電(dian)壓(ya)
電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)長度(du)的變(bian)化(hua)而變(bian)化(hua)，電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)拉長了，電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)則升高(gao)，電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)挺度(du)下(xia)降，母材受熱面(mian)增(zeng)加(jia)，所以焊接熔(rong)池的深(shen)度(du)減(jian)小，焊縫(feng)寬度(du)明顯增(zeng)寬。適當的增(zeng)加(jia)電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，會(hui)提高(gao)焊縫(feng)質量(liang)，但應與增(zeng)加(jia)焊接電(dian)(dian)(dian)(dian)(dian)(dian)流相配(pei)合(he)。單純(chun)地(di)增(zeng)加(jia)電(dian)(dian)(dian)(dian)(dian)(dian)弧(hu)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，會(hui)使熔(rong)深(shen)減(jian)小，造成焊件未焊透。而且(qie)焊劑的熔(rong)化(hua)量(liang)大，增(zeng)加(jia)焊劑的消耗量(liang)。焊縫(feng)表面(mian)粗糙，脫渣困難，嚴重時，會(hui)造成焊縫(feng)邊緣咬(yao)邊。
③. 焊接速度
當(dang)焊(han)接(jie)(jie)電(dian)流和電(dian)弧電(dian)壓不變時，焊(han)接(jie)(jie)速度(du)提高，電(dian)弧給予焊(han)接(jie)(jie)熔池中單位長度(du)的(de)熱量勢必減(jian)少，導致(zhi)焊(han)縫熔深和焊(han)縫寬度(du)減(jian)小。過分(fen)的(de)增加焊(han)接(jie)(jie)速度(du)，會導致(zhi)焊(han)接(jie)(jie)電(dian)弧對工件(jian)(jian)的(de)加熱不足(zu)，造(zao)成焊(han)件(jian)(jian)未(wei)焊(han)透(tou)和邊(bian)緣未(wei)熔合(he)等缺陷。
④. 焊(han)接材料
a. 壓(ya)力容器常(chang)(chang)用(yong)(yong)不銹(xiu)鋼(gang)埋(mai)弧(hu)(hu)焊(han)(han)(han)(han)焊(han)(han)(han)(han)絲(si)、焊(han)(han)(han)(han)劑(ji)見表(biao)4-14，常(chang)(chang)用(yong)(yong)奧(ao)氏(shi)體型耐熱鋼(gang)埋(mai)弧(hu)(hu)焊(han)(han)(han)(han)焊(han)(han)(han)(han)劑(ji)與焊(han)(han)(han)(han)絲(si)見表(biao)4-15，結(jie)構(gou)件常(chang)(chang)用(yong)(yong)奧(ao)氏(shi)體不銹(xiu)鋼(gang)埋(mai)弧(hu)(hu)焊(han)(han)(han)(han)焊(han)(han)(han)(han)劑(ji)與焊(han)(han)(han)(han)絲(si)見表(biao)4-16。
b. 常用不(bu)銹鋼埋弧焊用焊劑烘焙要求(qiu)見表(biao) 4-17 。
c. 焊劑顆粒度。熔煉焊劑顆粒度為2.5～0.45mm（4～40目），燒結焊劑顆粒度為2～0.28mm（10～60目），焊劑允許(xu)重(zhong)(zhong)復使用，但(dan)重(zhong)(zhong)復使用前(qian)須篩出細粉和渣(zha)殼，并(bing)與(yu)新焊劑混勻(yun)后使用。
⑤. 焊絲直徑
焊絲直徑加粗(cu)，電弧范圍擴大，使熔寬增(zeng)加；如果焊接電流保持不變，電流密度(du)減(jian)小(xiao)，電弧挺度(du)下(xia)降，則熔深將相(xiang)應地減(jian)小(xiao)。
⑥. 焊絲偏移量(liang)a
焊(han)(han)(han)(han)(han)(han)接環(huan)焊(han)(han)(han)(han)(han)(han)縫時(shi)(shi)(shi)，焊(han)(han)(han)(han)(han)(han)絲(si)(si)不應在最(zui)(zui)高點(dian)(dian)或最(zui)(zui)低(di)點(dian)(dian)，而應在下坡焊(han)(han)(han)(han)(han)(han)的(de)位置上，如(ru)圖(tu)(tu)4-19所示。焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)直接影(ying)響焊(han)(han)(han)(han)(han)(han)縫成形，見(jian)(jian)圖(tu)(tu)4-18。焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)與焊(han)(han)(han)(han)(han)(han)件外(wai)徑(jing)和焊(han)(han)(han)(han)(han)(han)接線(xian)能量(liang)有關。當焊(han)(han)(han)(han)(han)(han)接線(xian)能量(liang)大(da)(da)時(shi)(shi)(shi)，熔池(chi)(chi)停(ting)留時(shi)(shi)(shi)間較(jiao)長，所以(yi)焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)可選較(jiao)大(da)(da)值。當焊(han)(han)(han)(han)(han)(han)接線(xian)能量(liang)小(xiao)時(shi)(shi)(shi)，熔池(chi)(chi)停(ting)留時(shi)(shi)(shi)間較(jiao)短，所以(yi)焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)選取較(jiao)小(xiao)值。當焊(han)(han)(han)(han)(han)(han)件外(wai)徑(jing)較(jiao)大(da)(da)時(shi)(shi)(shi)，熔池(chi)(chi)中的(de)液態金屬(shu)外(wai)溢的(de)傾向較(jiao)小(xiao)，此時(shi)(shi)(shi)，焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)可取較(jiao)大(da)(da)值。焊(han)(han)(han)(han)(han)(han)絲(si)(si)直徑(jing)小(xiao)于(yu)3mm時(shi)(shi)(shi)，焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)一般不超過5～10mm，焊(han)(han)(han)(han)(han)(han)絲(si)(si)直徑(jing)大(da)(da)于(yu)3mm時(shi)(shi)(shi)，焊(han)(han)(han)(han)(han)(han)絲(si)(si)偏(pian)(pian)移(yi)量(liang)見(jian)(jian)表4-18。
⑦. 焊(han)絲(si)干伸長度(du)L
焊(han)絲(si)(si)前(qian)端(duan)到(dao)導電嘴前(qian)端(duan)的距(ju)離(li)稱(cheng)為焊(han)絲(si)(si)干(gan)伸長度(du)，見圖4-20。焊(han)絲(si)(si)干(gan)伸長度(du)L增加(jia)，焊(han)絲(si)(si)的預熱溫度(du)增加(jia)，焊(han)絲(si)(si)熔化速度(du)增加(jia)，增加(jia)焊(han)絲(si)(si)干(gan)伸長度(du)可提高(gao)生產效率，但焊(han)絲(si)(si)干(gan)伸長度(du)超過(guo)50mm后會(hui)出現成(cheng)段爆(bao)裂(lie)現象。所以焊(han)絲(si)(si)干(gan)伸長度(du)一(yi)般控制在17～20mm范(fan)圍內。
⑧. 電流種類和電極極性
在(zai)一般情況(kuang)下(xia)，電(dian)(dian)(dian)弧(hu)陽(yang)極(ji)(ji)區的(de)(de)溫度(du)較陰(yin)極(ji)(ji)區的(de)(de)溫度(du)高(gao)(gao)，但(dan)在(zai)使(shi)(shi)用高(gao)(gao)錳(meng)高(gao)(gao)硅含(han)氟的(de)(de)焊劑進(jin)行埋弧(hu)焊時，電(dian)(dian)(dian)弧(hu)空間氣(qi)體(ti)(ti)的(de)(de)電(dian)(dian)(dian)離(li)勢增加(jia)，這樣(yang)，氣(qi)體(ti)(ti)電(dian)(dian)(dian)離(li)后正離(li)子釋放至陰(yin)極(ji)(ji)的(de)(de)能量也增加(jia)，使(shi)(shi)陰(yin)極(ji)(ji)的(de)(de)溫度(du)提高(gao)(gao)，并大于(yu)陽(yang)極(ji)(ji)的(de)(de)溫度(du)。因而在(zai)用含(han)有高(gao)(gao)電(dian)(dian)(dian)離(li)電(dian)(dian)(dian)位的(de)(de)埋弧(hu)焊劑時，若焊接(jie)(jie)電(dian)(dian)(dian)源為(wei)直(zhi)(zhi)流(liu)正接(jie)(jie)，則焊絲(si)的(de)(de)熔化速(su)(su)度(du)大于(yu)焊件的(de)(de)熔化速(su)(su)度(du)，使(shi)(shi)接(jie)(jie)頭(tou)熔深減小(xiao)，焊縫余高(gao)(gao)增加(jia)。反之用直(zhi)(zhi)流(liu)反接(jie)(jie)便可(ke)增加(jia)熔深。使(shi)(shi)用交流(liu)焊接(jie)(jie)電(dian)(dian)(dian)源時，對(dui)形狀的(de)(de)影響(xiang)介于(yu)直(zhi)(zhi)流(liu)正接(jie)(jie)、反接(jie)(jie)之間。
上(shang)(shang)述(shu)各項(xiang)焊接(jie)參數(shu)的選(xuan)擇，不能單項(xiang)考(kao)(kao)慮，要有機地匹(pi)配(pei)，進行(xing)綜合(he)平衡分析(xi)，找出(chu)一個(ge)主要焊接(jie)參數(shu)，在充分試驗后(hou)，才能制訂出(chu)最佳參數(shu)。最終要經過焊接(jie)接(jie)頭的力(li)學性能考(kao)(kao)核和耐腐蝕性能試驗（即(ji)焊接(jie)工藝評(ping)定合(he)格(ge)），滿足產品(pin)設計圖樣要求后(hou)，方(fang)能在產品(pin)上(shang)(shang)正式施焊。表4-19、表4-20所(suo)列出(chu)的18-8型奧氏(shi)體不銹鋼焊接(jie)參數(shu)可供參考(kao)(kao)。
