THE FORMATION FEATURES OF PIPES STRENGTH CHARACTERISTICS MADE OF MASS GRADES OF AUSTENITIC STAINLESS STEELS AT ROOM AND ELEVATED TEMPERATURES

As part of the research on the development of a new standard for welded and seamless stainless steel pipes, the microstructure, phase composition and mechanical properties in the temperature range of 20-650 °C of pipe samples from austenitic chromium-nickel steels of the Fe-18Cr-10Ni family were evaluated. Significant spread of mechanical characteristics is shown, a quantitative assessment of the contribution of various hardening factors is carried out. It is noted that grain size and solid-solution hardening with carbon, nitrogen or titanium have the most significant effect on mechanical properties, providing up to 45% of the yield strength of steel. It is established that the temperature dependence of the tensile strength is determined by the resistance to the formation of deformation martensite and the intensity of the action of dynamic deformation aging.