| 摘要 |
FIELD: metallurgy. ^ SUBSTANCE: for getting the hot-rolled steel sheet with low specific gravity and high mechanical strength the sheet contains the ratio of components, the weight %: 0.04 <= carbon <= 0.5, 0.05 <= manganese <= 3.0, 2.0 <= silicon <= 10.0, 1.0 <= aluminum<= 10.0, iron and inevitable touch - others, microstructure of ferrite is arise by primary and secondary ferrite phase, at the same the average size of ferrite grain of primary phase exceed the average size of ferrite grain of secondary phase. The steel sheet additionally contains strengthening elements, taken separately or in combination, the weight %: 0.01 <= niobium <= 0.1, 0.01 <= titanium <= 0.2, 0.01 <=vanadium <= 0.2 and elements effects to the transformation temperature, taken separately or in combination, the weight %: 0.0005 <= boron <= 0.005, 0.05 <= nickel <= 2.0, 0.05 <= chromium <= 2.0, 0.05 <= molybdenum <= 2.0. Primary ferrite phase is got during process of steel sheet heating before hot-rolling with average grain size more then 5 mcm, and secondary ferrite phase - in the result of hot-rolling with average grain size 2 mcm. The way of getting of the hot-rolled steel sheet includes the heating of slab with creating in it the microstructure, contained primary ferrite and austenite phases, the forth coming slab hot-rolling, at the same the temperature of the end of hot-rolled is exceed the temperature r3 of austenite phase, generated during the heating and necessary for organizing the rolling. ^ EFFECT: transformation of austenite phase into secondary ferrite phase and carbide phase. ^ 21 cl, 1 tbl, 5 dwg |
