Investigation of Mechanical Properties and Microstructure of Weld Overlay Cladding of Low Alloy Steel with Austenitic Stainless Steel and Comparison of Hydrogen Embrittlement on Joining

Dissimilar joints between austenitic stainless steels and low alloy and carbon steels have many usages in various industries and also have economic aspects. Loss of mechanical properties can be influenced by existence of hydrogen in corrosive enviroments. The effects of hydrogen on joints between carbon steel (A516) and stainless steel (AISI347) are compared and discussed in this research. For this reason samples made up from low-alloy steel prepared, then cladded with stainless steel 321 and Er347 by process of Gas Tungsten arc welding (GTAW). Then cladded samples putted under hydrogen cathodic charging. Ultrasonic tests, metallography, hardness measurment, bending and microscopic analysis (EDS) have used in order to compare these mechanical properties with uncharged samples. Result of these experiments shows that both materials, showed corrosion resistance against corrosive areas, but samples have broken from their interface while using force and penetrating hydrogen into it. In other hand it was seen separation in the interface of A516-Gr70 and AISI 321. Totally results show that AISI 347 clad shows better resistance than covered C-Steel with AIS 321.