Effect of treatment from the intercritical interval on the state of the carbide phase in chromium steel

Abstract

1. an increase in the plasticity and resilience of chromium type 10Kh9MFB steel after heat treatment is associated primarily with variation in the form of segregation and the character of the distribution of the carbide phase M23C6. 2. After air quenching from 1050°C (i.e., above Ac3), carbides with an acute-angle, platelike shape, which are distributed preferentially along the grain boundaries and bainitic laths, are segregated in steel 10Kh9MFB during tempering in the 600–700°C interval. These carbides are unstable during tempering, and effect an increase in the percent of brittle intergranular failure; this leads to a reduction in the steel's plasticity and resilience. 3. Spheroidized carbides M23C6 of equiaxial shape, which are uniformly distributed along the grain boundaries and body, are segregated when chromium type 10Kh9MFB steel is heated in the intercritical region. These carbides are in equilibrium with the matrix and retain their own stability over a broad range of tempering temperatures from 600 to 760°C, ensuring high plasticity and resilience when the steel's failure is ductile in nature.