Effect of welding process parameters on embrittlement of Grade P92 steel using Granjon implant testing of welded joints. (20th March 2020)

• Record Type: Journal Article
• Authors: Saini, Nitin; Mulik, Rahul S.; Mahapatra, Manas Mohan
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 16(2020)
• Page Start: 10189
• Page End: 10198
• Publication Date: 2020-03-20
• Subjects: Mercury method -- Granjon implant test -- Grade P92 steel -- HAZ-HAC; CSEF Creep strength enhanced ferritic -- HAC Hydrogen-assisted cracking -- HAZ Heat-affected zone -- LCS Lower critical stress -- SCC Stress corrosion cracking -- PWHT Post-weld heat treatment -- SMAW Shielded metal arc welding -- FESEM Field emission secondary electron microscope -- CGHAZ Coarse grain heat-affected zone -- FGHAZ Fine grain heat-affected zone -- PAGB's Prior austenite grain boundaries -- EI Embrittlement index; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.01.146
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Precipitation of Cr-rich carbides, diffusible hydrogen content and heterogeneous microstructure formation across the weldments makes heat-affected zone (HAZ) susceptible to intergranular cracking and makes weldability of creep strength enhanced ferritic (CSEF) Grade P92 steel a critical issue. In the present research work, the Granjon implant test and mercury method (for diffusible hydrogen measurement) have been performed on Grade P92 steel welded specimens to study the effect of welding parameters on diffusible hydrogen levels and their subsequent effect on hydrogen-assisted cracking (HAC). The weld metal was deposited by a shielded metal arc welding process on Grade P92 steel samples using P92 matching filler. The three different welding conditions are used to measure the diffusible hydrogen level in the deposited metal. Granjon implant test was performed to evaluate HAZ HAC susceptibility with similar welding conditions which were used in the mercury method. Lower critical stress (LCS) was also evaluated using the Granjon implant test. The higher susceptibility of CSEF Grade P92 steel welded plate towards HAZ HAC was noticed in case of lower heat input or higher diffusible hydrogen content. However, by considering LCS, fracture mode and diffusible hydrogen content, the weld deposited using the highest heat input (condition III) offers great resistance to HAZ HAC. Graphical abstract: Image 1 Highlights: Effect of diffusible hydrogen on lower critical stress using Granjon implant test. The effect of heat input on the microstructure evolution. HAZ hydrogen assisted cracking susceptibility of P92 steel welds. Effect of varying diffusible hydrogen on fracture morphology of implant specimen.