Martensitic chromium@ steel - has good wear resistance and high temp. tensile strength, used in building parts

摘要

Martensitic Cr-steel consists of a wt.%:- 0.005-0.5 C; 0.2-2.0 Si; max. 1.0 Mn; max. 0.025 P; max 0.025 S; 14-18 Cr; 0.5-3 Mo; 0.5-3 W; 0.3-2 Ni; 0.2-1.0 N; 0.2-1.0 V; max. 0.5 Nb and/or Ti; max. 0.01 B; balance Fe and usual impurities. The ratio of C:N is 0.4-0.8 and (C+N):V is 1.5-2.5. After hot working the steel is air cooled before being heated to 950-1200 deg.C and then rapidly quenched in oil or water to below the martensite forming temp. Finally it is tempered at 500-650 deg.C before being air cooled to room temp. USE/ADVANTAGE - In building parts. Steel has high tensile strength of above 1800 MPa at room temp., high strength of above 1000 MPa at 500 deg.C and excellent corrosion resistance esp. in acids and/or chloride solutions. Also has the necessary wear resistance with a hardness of 40 HRC.