Hydrogen embrittlement of austenitic stainless steel/carbon steel dissimilar metal welds

M. M. Alelyani, S. L.I. Chan

Research output: Contribution to conferencePaperpeer-review

Abstract

The influence of hydrogen on mechanical properties of dissimilar metals weld (DMW) between 304 austenitic stainless steel and carbon steel was studied using cathodic charging technique. Multipass gas tungsten arc welding (GTAW) process was used to weld this dissimilar metals combination using two different filler metals; ER309 and INCONEL82. In this study, tensile tests, hardness and microscopic investigations were carried out to examine the performance of 304-CS DMW in hydrogen environment. It was found that narrow hardened transition zone at the heat-affected zone (HAZ) of carbon steel was formed in all welds, and it had a significant influence on the hydrogen embrittlement susceptibility of DMW. In tension tests, the weldments using ER309 filler metal, failed in the fusion zone, whereas the DMW samples with INCONEL 82 failed at the HAZ of the carbon steel. The SEM results showed ductile fracture surface with tear and fisheye effect due to the dissolved and accumulated hydrogen in the lattices of carbon steel, which formed stresses and plastic deformation. The carbon steel exhibited remarkable sensitivity to hydrogen embrittlement, while only thin surface layer in the 304 stainless steel was affected, because of the slow hydrogen diffusivity in austenitic structure. Based on the findings in this investigation, the welded joints are susceptible to hydrogen embrittlement in the heat-affected zone and in the fusion zone. The hydrogen effects were shown by the distinct decrease of ductility, a slight decrease of strength and clear damage of microstructure.

Original languageEnglish
StatePublished - 2015
EventAustralasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015 - Adelaide, Australia
Duration: 15 Nov 201518 Nov 2015

Conference

ConferenceAustralasian Corrosion Association Annual Conference: Corrosion and Prevention 2015, ACA 2015
Country/TerritoryAustralia
CityAdelaide
Period15/11/1518/11/15

Keywords

  • 304 stainless steel
  • Dissimilar metals
  • Hydrogen embrittlement
  • Welding

Fingerprint

Dive into the research topics of 'Hydrogen embrittlement of austenitic stainless steel/carbon steel dissimilar metal welds'. Together they form a unique fingerprint.

Cite this