船舶焊接CO2气体保护单面焊气孔成因探讨

ＣＯ２气体保护半自动单面焊用于船舶焊接，提高了焊接质量，减轻了焊工的劳动强度，半缩短了造船周期。但是单面焊打底层焊缝中出现的沿焊缝柱状晶结晶方向的柱状气孔，严重地影响着船舶焊接质量。

Cause Study of Porosities Formation in Semiautomatic CO_2 Arc Welding by One Side with Ceramic Backing Strip

When the CO_2 arc welding by one side with ceramic backing strip is applied in shipbuilding semiautomatic welding procedure, the quality of welding can be approved, the labor intensity of welder will be reduced and consequantly the period of shipbuilding will be shorten. But in the backing welding, columnar grain-growth will be appeared in the direction of crystal direction, it effects the welding quality seriously . In order to avoid this kind of damage, an experiment has been carried out in the laboratory to simulate the condition. Through macro and micro analysis for the same columnar porosity obtained, the main cause is discovered and some preventive measures are suggested accordingly.