Original paper(Vol.51 No.4 pp.412)

Boronizing and Solid Particle Erosion Resistance of 12%Cr Heat Resistant Steel

Matsuo MIYAZAKI and Kazuaki IKEDA

Abstract:In order to cope with the severe solid particle erosion damage of 12%Cr steel for steam turbine nozzles, erosion tests were conducted at high temperature, by using high velocity iron oxide for solid particles. With respect to the behavior of erosion damage, the effects of impact angles and velocity of iron oxide, hardness and surface treatments of target materials were made clear. And a boronized 12%Cr steel was superior resistant to the erosion. This paper describes the characteristics of boronized layer of 12%Cr steel with excellent erosion resistance, the relationship between damage and some erosion factors and the application of boronized 12%Cr steel nozzles in actual steam turbines.

Key Words:Erosion, Solid particle erosion, Boronizing, Boride coating, Surface treatment, 12%Cr steel