Abstract
Weld overlays of austenitic stainless steels on 2.25Cr-Mo steel were made by the shielded metal arc welding process. Single layer weld overlays (SLWO) of 3 mm thick were made by using either E309 (A-type specimen) or E347 (B-type specimen) electrodes and double layer weld overlays (DLWO) were made by depositing 1 mm of E309 and then 2 mm of E347 on the steel (C-type specimen). Constant extension rate tensile (CERT) tests were performed to investigate the fracture characteristics of the weld overlay specimens in air and in H 2S solution. Cracks were initiated at the fusion boundaries between the stainless steel deposit and 2.25Cr-Mo steel substrate, and then propagated normally to loading direction into the steel substrate and stainless steel deposit. This procedure was repeated for all types of specimens in the as-welded condition. The results revealed the untempered narrow diluted zone (DZ) and heat-affected zone (HAZ) were susceptible to hydrogen embrittlement (HE). However, the high susceptibility of the HAZ to HE could be reduced significantly in all specimens by tempering at 690 °C for one hour. The susceptibility to cracks in the DZ was lower for the A-type specimens than the B-type and C-type specimens. C-type specimens had the declined tensile strength, which could be attributed to the extensive dilution in the first layer deposit, resulting in a high susceptibility to HE.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
