Hydrogen assisted cracking in C-Mn and low alloy steel weldments

Abstract

Hydrogen assisted cracking (cold cracking) in the heat affected zones of welded C-Mn and low alloy steels and their weld metals is discussed with regard to hydrogen diffusion, residual stress, and microstructure. The features of the hydrogen-assisted cracking tests so far proposed are reviewed and correlations between results by different cracking tests are discussed. The effects of steel chemical composition, including microalloying elements and impurities, are discussed, and the adequateness of various carbon equivalents proposed, depending on the type of steel, is described. On the basis of factors influencing hydrogen cracking, methods to determine safe welding conditions are discussed.