Someboy please advice smart and result orient heat treatment cycle for 18% Ni Maraging Steel. Can we do grain refinement of 18 Pct Ni Maraging Steel in a single step via heat treatment? We have done heat treatment at 820 degree C, howerer the results showed localized coarse grains (inhomogeneity in grain size). We have tried to lower the grain size in multiple heat treatment steps such as 860, then 840, then 820. This is also supported by previous literature (Can somebody explain what is the advantages of multistep heat treatment in case of 18% Ni marging steel). Some one in literature also used higher temp 850 after the 820, why so?. Although, grain size reduces but there is alot of variation in gain size. We are using controlled and accurate readout furnace. Please suggest how to overcome this problem? Thanks