A consideration is given to the influence of thermodynamic and kinetic factors on dissolution of carbide, nitride and carbonitride phases in steel matrix. Possibilities of dissolution simulation using analytical, semi-analytical and numerical methods are discussed. Numerical methods allowed plotting nomograms for determination of dissolution degree for carbides and nitrides in steels of various compositions after various heat treatments. The nomograms can be used for selection of heat treatment conditions ensuring required degree of excess phase dissolution.