影響埋弧焊接不銹鋼管(guan)操作因素主要有以下兩點:
一、焊絲(si)傾斜(xie)方向的影響
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、焊縫傾角(inclination of weld axis,焊縫軸線與水平面之間的(de)夾角)對(dui)焊縫成形(xing)的(de)影(ying)響(xiang)
焊(han)(han)(han)(han)件(jian)在(zai)傾斜位置焊(han)(han)(han)(han)接時,有(you)上(shang)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)和(he)下(xia)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)之分,如(ru)圖4-22所(suo)示。上(shang)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)、下(xia)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)對焊(han)(han)(han)(han)縫(feng)成形(xing)(xing)的影響明(ming)顯地不(bu)同。上(shang)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)時,焊(han)(han)(han)(han)縫(feng)余高(gao)過高(gao),兩側易出現咬邊,焊(han)(han)(han)(han)縫(feng)表面成形(xing)(xing)明(ming)顯惡化,實際工作(zuo)中應避免采用(yong)上(shang)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)。下(xia)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)與上(shang)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)相反,焊(han)(han)(han)(han)縫(feng)的熔(rong)深和(he)余高(gao)均有(you)所(suo)減小(xiao),而焊(han)(han)(han)(han)縫(feng)寬度(du)略有(you)增加,焊(han)(han)(han)(han)縫(feng)成形(xing)(xing)得到改善。在(zai)焊(han)(han)(han)(han)接圓筒焊(han)(han)(han)(han)件(jian)的內、外環焊(han)(han)(han)(han)縫(feng)時,一般(ban)均采用(yong)下(xia)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han),以減少發生(sheng)燒穿的現象,并改善焊(han)(han)(han)(han)縫(feng)成形(xing)(xing)。但焊(han)(han)(han)(han)件(jian)下(xia)坡(po)(po)(po)(po)(po)焊(han)(han)(han)(han)的角(jiao)度(du)過大時,熔(rong)深減小(xiao)可能產生(sheng)未焊(han)(han)(han)(han)透焊(han)(han)(han)(han)接缺陷。


