不锈钢换热器厚壁壳体双丝窄间隙埋弧焊工艺

Tandem wire narrow gap submerged arc welding process of thick stainless steel shell of heat exchanger

根据不锈钢的热导率小而线膨胀系数大,厚板焊接会产生较大的焊接应力,合金元素及杂质的偏析容易产生热裂纹,需采用低热输入并控制层间温度等工艺措施。厚壁壳体的不锈钢垫板焊后不易去除,设计制作了碳钢-不锈钢复合垫板。确定壳体焊接坡口形式及焊接工艺参数,制定壳体组焊方案及防变形措施,壳体环焊缝焊接使用防窜滚轮架。

The thermal conductivity of stainless steel rate is low,and the linear expansion coefficient is large,so great welding stress will appear in welding of thick plate and the segregation of alloy elements and impurities easily leads to hot cracking.It is necessary to adopt the low welding heat input,and control the interpass temperature.Stainless steel backing plate is not easy to remove after welding,and carbon steel/stainless steel composite backing plate was designed and prepared.The groove type and welding parameters were determined,and the assembly welding scheme and the measures were made to prevent deformation,weld welding using anti channeling roller.