Premium
Investigation of the conditions for weld metal hydrogen cracking of low carbon offshore steels by the IRC weldability test
Author(s) -
Hoffmeister Hans,
Harneshaug Idar S.,
Roaas Stig
Publication year - 1987
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.198701518
Subject(s) - weldability , metallurgy , cracking , materials science , welding , hydrogen embrittlement , heat affected zone , hydrogen , base metal , composite material , corrosion , chemistry , organic chemistry
Three low carbon structural steels of different plate thickness have been investigated for hydrogen assisted cold cracking by the IRC weldability test at different restraint intensities. At diffusible hydrogen levels of 10–15 N ml/100 g Fe (ISO 3690), cracking decreases at increasing heat inputs due to a drop in restraint stress and hardness as well as an increase in hydrogen diffusion times. Critical heat inputs for crack prevention range from 0.95 to 1.4 kJmm −1 . Higher restraints enforce higher cracking stresses as well as final stresses of uncracked test welds. Higher restraints and lower heat inputs also induce faster stress increase during cooling which, for the steels containing Ni and Cu, shift the location of cracking from the HAZ to the weld metal. The steel without Ni and lower maximum HAZ hardness reveals weld metal cracking only, regardless of welding conditions. It can be concluded that for weld metal cracking, the relation between stress increase‐ and hydrogen effusion rates but also the relation between weld metal and HAZ microstructure and mechanical properties are responsible.