FACTORS AFFECTING QUALITY OF DISSIMILAR PLATE SUBMERGED-ARC WELDS

Submerged are welding of stainless steel to carbon steel plate can pro duce a number of quality problems. These problems are lack of penetrat ion defects low ferrite numbers in the weld metal, and presence of mar tensite in the microstructure. It has been established that the positi on of the electrode wire in the weld preparation is critical to the in tegrity of the weld. Offsetting the wile position to the stainless ste el side of the preparation has two effects. First, it exposes more sta inless steel to the are for a second side pass, which results in incre ased penetration and removes the potential for occurrence of lack of p enetration defects. Second it alters the dilution of the weld metal, w hich governs the fel rite number of the weld metal, and it also contro ls the final microstructure of the weld metal. It has been established that a high ferrite number (> 60) consumable wire should be used to p roduce a satisfactory weld.