HOT-FORMED GREEN STEEL OF MARTENSITIC CLASS AND HOT-FORMED GREEN STEEL PART

摘要

FIELD: metallurgy.;SUBSTANCE: green steel of martensitic class for hot forming includes the components in the following ratio, wt %: 0.10 to 0.20 C, 0.10 to 0.50 Si, 1.0 to 3.0 Mn, 0.001 to 0,1 P, 0.005 to 0,8 S, 0.10 to 1.50 Cr, more than 0.1 to 0.20 Al, 0.0020 to 0.0080 N; Fe and inevitable impurities are the rest. After the shape is changed with hot forming, there applied is controlled cooling to create in steel of the main structure being martensite even without further repeated heating and heat treatment including hardening and drawing. Hot-formed green steel part made form this steel has steel structure in the whole cross section of some portion of the part or the whole part, which is mainly martensitic steel with effective grain size of 15 mcm or less.;EFFECT: steel part has high strength, high viscosity and excellent processibility.;5 cl, 1 dwg, 3 tbl, 1 ex