9-12% Cr Heat-Resistant Martensitic Steels with Increased Boron and Decreased Nitrogen Contents

Abstract

As a promising alloying approach, the modification of chemical composition by increasing the B content and decreasing the N content has been applied to improve the creep resistance of various 9-12% Cr heat-resistant martensitic steels. This paper presents an overview of the creep strength and related microstructural features of the 9% Cr and 10-12% Cr martensitic steels with high B and low N contents. The factors that determine the optimal B/N ratio in steels are considered