Precipitation strengthening of steel is one of the most important phenomena used to obtain high strength steel. By adding strong carbide forming elements to the steel, secondary carbides are formed upon low temperature annealing. These carbides pin dislocations and stabilize, and in some cases increase, the strength of the material. However, the formed particles are considered to be both small and few, and by conventional methods, e.g. transmission electron microscopy, it is necessary to analyse many samples in order to get statistical significant data. Small angle neutron scattering is a more suitable method for analyzing small particles and large enough sample volumes to get reliable data, both ex-situ and in-situ. The purpose of our experiment is to use SANS in order to follow the precipitation sequence during annealing of commercially interesting steels.