Hydrogen is a potential energy carrier to replace fossil fuels, thus reducing emissions of greenhouse gases and decreasing global warning. Pipelines will form part of the hydrogen supply system. Microalloyed steel welds are susceptible to hydrogen cracking effects. Welding is normally used to construct pipelines and the welding process can create issues with the hydrogen effects on weld metal, heat affected zone and the base metal of the steel. Compositional and processing variables influence the microstructural features that can be produced by posterior welding, for example, in the heat affected zones, and these features can alter the hydrogen trapping and...