影響埋弧焊接不(bu)銹(xiu)鋼管操作因素主要有以下兩點:
一、焊絲傾(qing)斜方向的影(ying)響(xiang)
焊絲傾斜方向分為前傾和后傾兩種,如圖4-21所示。焊絲傾角的大小不同,電弧對熔池的力和熱作用也就不同,從而影響到焊縫成形。當焊絲以一定傾角向后傾時,電弧力對熔池金屬的后緣作用減弱,熔池底部的金屬受熱減少,故熔深變淺,如圖4-21(c)所示。后傾角愈大,熔深愈淺,而熔寬增寬。相反,當焊絲做適當前傾時,可少許增加熔深。焊絲前傾斜通常較少采用,只有在特定情況下使用,如焊接小直徑圓筒形焊件的環焊縫時采用這種方法。
二、焊縫傾(qing)角(inclination of weld axis,焊縫軸線與水(shui)平面之間的夾角)對焊縫成形的影響
焊(han)(han)(han)(han)(han)件在傾斜位置焊(han)(han)(han)(han)(han)接時,有(you)上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)(han)和下坡(po)(po)(po)焊(han)(han)(han)(han)(han)之分,如圖4-22所示。上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)(han)、下坡(po)(po)(po)焊(han)(han)(han)(han)(han)對焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)成(cheng)形的(de)影響明顯地(di)不同(tong)。上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)(han)時,焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)余(yu)高過(guo)高,兩側易出現(xian)(xian)咬邊(bian),焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)表面成(cheng)形明顯惡化,實際工(gong)作中應(ying)避免采用上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)(han)。下坡(po)(po)(po)焊(han)(han)(han)(han)(han)與上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)(han)相反,焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)的(de)熔(rong)深(shen)和余(yu)高均有(you)所減(jian)(jian)小(xiao),而焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)寬度略有(you)增加,焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)成(cheng)形得到改善(shan)。在焊(han)(han)(han)(han)(han)接圓筒焊(han)(han)(han)(han)(han)件的(de)內(nei)、外環焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)時,一般均采用下坡(po)(po)(po)焊(han)(han)(han)(han)(han),以減(jian)(jian)少發生燒(shao)穿(chuan)的(de)現(xian)(xian)象,并改善(shan)焊(han)(han)(han)(han)(han)縫(feng)(feng)(feng)成(cheng)形。但焊(han)(han)(han)(han)(han)件下坡(po)(po)(po)焊(han)(han)(han)(han)(han)的(de)角度過(guo)大時,熔(rong)深(shen)減(jian)(jian)小(xiao)可能(neng)產生未焊(han)(han)(han)(han)(han)透(tou)焊(han)(han)(han)(han)(han)接缺陷。