水下局部排水CO2半自动焊气孔问题的研究

A STUDY OF WELD POROSITY IN LOCAL DRY CO2 GAS SHIELDED SEMI-AUTOMATIC UNDERWATER WELDING

摘要:

本文针对水下局部排水CO₂半自动焊中的气孔问题进行了初步探讨,着重研究了CO₂气体流量对气孔生成的影响。试验表明,气孔的性质为氢气孔,气孔的形态为螺钉状和条虫状两种。随着CO₂气体流量的增加,气孔率下降,气孔形态由螺钉状向条虫状演变.选择合适的CO₂气体流量使之形成稳定的背面气相区,是防止对接坡口封底焊道产生气孔的有效途径。

Abstract:

In this paper,the porosity in the welds of local dry CO₂ gas shielded semi-auto-matic underwater welding was studied,and the effect of CO₂ gas flow rate on the formation of porosity was stressed.It was found that there were two kinds of porosity in the welds,the "screw" shape and the "earth worm" shape.Both were of the hydrogen type.The porosity decreased with the increase of CO₂ gas rate,with its shape changing from "screw" into "earth worm".A suitable rate of CO₂ gas flow should be set to form a stable cavity at the back side of the groove in the root run of sealing weld,an effective way to prevent porosity.