Water cooling assisted laser dissimilar welding with filler wire of nickel-based alloy/austenitic stainless steel

•Adding water cooling made the weld grain refined by about 28% and the average width of unmixed zone decreased by 35%.•The precipitated phases are made up of p phase and μ phase which has obvious stacking faults along the direction of [1 1 0].•Both p phase and μ phase had a good coherent relationship with the matrix.•The coherent relationships of p phase and μ phase are described as [1 4 3]p//[5 3 1]γ and [1 2 0]μ//[2 2 1]γ.