Size stability and strength of multiphase metastable materials

The changes in the clearances (interferences) caused by the differences in the temperature coefficients of linear expansion (TCLE) of joined materials are considered. In operation and long-term storage of precision parts made of high-strength steels these changes can exceed the admissible ranges due to the instability of the phase composition even when the parameters of the heat-treatment process correspond to the existing technological recommendations. A study of the nature of the size instability of high-strength corrosion-resistant steel 25Kh17N2B-Sh allowed the authors to recommend regimes for its final heat treatment that provide maximum size stability at the specified level of mechanical properties.