影響埋弧焊接不(bu)銹鋼(gang)管(guan)操作因素主要有以下兩點:
一(yi)、焊(han)絲傾斜方(fang)向的影(ying)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(feng)傾角(inclination of weld axis,焊縫(feng)軸(zhou)線與水平面(mian)之間的夾角)對焊縫(feng)成形的影響
焊(han)(han)(han)(han)件在(zai)傾斜位置焊(han)(han)(han)(han)接時(shi),有(you)(you)上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)和下(xia)坡(po)(po)(po)焊(han)(han)(han)(han)之分,如圖4-22所示(shi)。上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)、下(xia)坡(po)(po)(po)焊(han)(han)(han)(han)對焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)成(cheng)(cheng)形(xing)的(de)影響明顯(xian)(xian)地不(bu)同(tong)。上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)時(shi),焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)余(yu)(yu)高過高,兩側易出現咬邊,焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)表(biao)面成(cheng)(cheng)形(xing)明顯(xian)(xian)惡化,實(shi)際(ji)工作中應避免采(cai)用上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)。下(xia)坡(po)(po)(po)焊(han)(han)(han)(han)與上(shang)坡(po)(po)(po)焊(han)(han)(han)(han)相(xiang)反(fan),焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)的(de)熔(rong)深(shen)和余(yu)(yu)高均(jun)有(you)(you)所減小(xiao),而焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)寬度略有(you)(you)增加(jia),焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)成(cheng)(cheng)形(xing)得到改(gai)(gai)善。在(zai)焊(han)(han)(han)(han)接圓(yuan)筒(tong)焊(han)(han)(han)(han)件的(de)內、外環(huan)焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)時(shi),一般均(jun)采(cai)用下(xia)坡(po)(po)(po)焊(han)(han)(han)(han),以減少(shao)發生燒穿(chuan)的(de)現象,并(bing)改(gai)(gai)善焊(han)(han)(han)(han)縫(feng)(feng)(feng)(feng)成(cheng)(cheng)形(xing)。但焊(han)(han)(han)(han)件下(xia)坡(po)(po)(po)焊(han)(han)(han)(han)的(de)角度過大時(shi),熔(rong)深(shen)減小(xiao)可能(neng)產(chan)生未(wei)焊(han)(han)(han)(han)透焊(han)(han)(han)(han)接缺陷。