Investigation of Structural Changes in High-Alloy Ferrite-Austenitic Steels.

摘要

Research was carried out with steel of the following composition: 0.16% C; 0.24% Mn; 0.26% Si; with steel 12.07% Cr; 8.07% Mo; 0.013 N, and with steel 2L with a content of 0.28% C; 0.17% Mn; 0.32% Si; 11.87% Cr; 8.09% Mo; 0.18% N. The work was carried out with the use of metallographic analysis, electrolytic isolation of the dispersion phases of X-ray and micro-chemical analysis, measurement of microhardness of delta ferrite and austenite and electronic microscopy. The effort concentrated on the study of structural changes during heating-up and cooling-down and during tempering in the region of temperatures of 500-800C and on the research on the isothemic desintegration of delta ferrite at temperatures of 800-1100C. The paper also comments on the determination of the activation energy of hardening processes in delta ferrite and austenite during tempering. The results of the research show the behaviour of delta ferrite during heating-up and cooling-down, the course of the delta - eutectoid reaction, the precipitation of carbides and intermetallic phases and the process of the de-stabilization and stabilization of austenite.