51312-01602-A New Test for Evaluation of the Susceptibility to Hydrogen Assisted Cracking in Dissimilar Metal We

Available for download

Product Number: 51312-01602-SG

ISBN: 01602 2012 CP

Author: Boian T. Alexandrov

Publication Date: 2012

Member Price: $0.00

Non Member Price: $20.00

Price: $20.00

Qty:

Dissimilar metal welds (DMWs) in high strength steels with Ni-base filler metals are widely used in the oil and petrochemical industries. Improper welding and post weld heat treatment (PWHT) of such welds can result in formation of extremely hard and brittle microstructure along the dissimilar fusion boundary that is highly susceptible to Hydrogen Assisted Cracking (HAC). A new test has been developed for evaluation of the susceptibility to HAC in DMWs. This test consists of accelerated electrolytic charging with hydrogen of DMW samples loaded with a constant tensile load normal to the dissimilar fusion boundary. The time to fracture at particular stress is used to rank the susceptibility to HAC. The influence of welding and PWHT procedures on the susceptibility to HAC in DMWs of F22 steel and Inconel 625 filler metal was assessed with this new test. The test proved to be very sensitive to the effects of PWHT parameters and welding bead sequence and replicated the fracture morphologies of in-service DMWs failures. The new test provides a reliable tool for ranking the susceptibility to HAC in DMWs for selection of optimal DMW material combinations and for development and optimization of welding and PWHT procedures.