The suitability of post-weld heat treatments are often measured in terms of reducing residual stress and/or ensuring hardness homogeneity. Here we use detailed digital image correlation to quantify the localised deformation behaviour of laser welded Eurofer-97 both with and without a normalising and tempering treatment. This is coupled with detailed microscopic analysis to investigate the mechanisms for the localised plasticity measured. We show that although the treatment ensures hardness homogeneity, there remains variation in grain size, texture, carbide morphology/density and tensile behaviour across the weld. A quantification of strain heterogeneity throughout the test provides a new measure of performance that indicates the suitability of both microstructure and macroscopic performance for engineering applications.