Effect of hot rolling on the structure and the mechanical properties of nitrogen-bearing austenitic–martensitic 14Kh15AN4M steel

Resumo

The effect of the rolling temperature and strain on the structure and the properties of corrosionresistant austenitic–martensitic 14Kh15AN4M steel is studied. The steel is shown to exhibit high ductility: upon rolling in the temperature range 700–1100°C at a reduction per pass up to 80%, wedge steel specimens are uniformly deformed along and across the rolling direction without cracking and other surface defects. Subsequent cold treatment and low-temperature tempering ensure a high hardness of the steel (50–56 HRC). Austenite mainly contributes to the hardening upon rolling in the temperature range 700–800°C at a reduction of 50–70%, and martensite makes the main contribution at higher temperatures and lower strains. Texture does not form under the chosen deformation conditions, which indicates dynamic recrystallization with the nucleation and growth of grains having no preferential orientation.