Process Parameter Relationship Of Stainless Steel To Carbon Steel Pipes Welding

Dissimilar pipe welding is widely used in industry especially power plant. The purpose of this method is to have the transition in mechanical properties to meet the requirement in different working condition. In addition, the economic purpose is another important factor because 304L austenitic stainless steel pipe is more expensive than BS1387 low carbon steel and material cost is limited for industry. The 304L austenitic stainless steel is used in the critical environment like high pressure and temperature region while BS1387 is used in low pressure and temperature region. In order to join both pipes, Gas Metal Arc Welding is performed and rotating jig is used to increase the consistency of the welding process. However, different physical properties of two different types of the steels cause them hard to join together. Hence, the objectives of this study are to study the effect of welding parameters that are current and welding speed to tensile and hardness properties of welded specimens, suggest optimized parameters for BS 1387 and SS 304L pipes welding and generate the regression models of tensile and hardness properties in BS1387 and SS304L pipes welding. Various currents and welding speeds are introduced and they are 175, 180, 185A and 60, 70, 80cm/min. Mechanical tests like tensile testing and microhardness testing are carried out after all the welding specimens were cut into desired shape by using Electro-Discharge Machine. The results revealed that welding speed is dominants the influence to the changes of the strength and hardness of the welded zone. Moreover, optimized set of parameters and regression models are suggested.