Austenite Grain Growth Law of High-strength Steel for Offshore Engineering

Abstract

The metallographic analysis method is used to study the original austenite grain change law of Nb-containing high-strength ship steel. Adding Nb to the experimental steel will refine the grains to a certain extent. Different Nb content, the corresponding grain size change trend is different. Under the experimental heating environment of 850°C~1150°C, the grains of the two experimental steels have different degrees of coarsening at different heating temperatures. Compared with the low-C and high-Nb steel (EH36) with the high-C and low-Nb steel (AH36), the former can not only control the austenite grain growth well at lower temperature, but also has a strong inhibitory effect in a higher temperature environment. Based on the experimental data, the austenite grain growth kinetic model of the two experimental steels at the heating temperature of 850°C~1150°C is obtained.