Niobium and vanadium-containing economical high-strength and high-weather-resistance hot rolled H-shaped steel and rolling method thereof

Abstract

The invention discloses a niobium and vanadium-containing economical high-strength and high-weather-resistance hot rolled H-shaped steel, which is characterized by comprising the following chemical compositions in percentage by weight: 0.07 to 0.12 percent of C, 0.30 to 0.55 percent of Si, 1.30 to 1.55 percent of Mn, 0.020 to 0.045 percent of P, 0.001 to 0.010 percent of S, 0.25 to 0.35 percent of Cu, 0.20 to 0.30 percent of Cr, 0.15 to 0.30 percent of Ni, 0.04 to 0.08 percent of V, 0.02 to 0.05 percent of Nb, 0.006 to 0.030 percent of Als and the balance of Fe and residual trace impurities. The invention also discloses a rolling method for the H-shaped steel, wherein the soaking temperature of a casting blank is 1,195 to 1,225 DEG C; the start rolling temperature of a breaking down mill is 1,100 to 1,150 DEG C; the finish rolling temperature of the breaking down mill is 980 to 1,030 DEG C; the start rolling temperature of a universal roughing mill is 900 to 950 DEG C; the finish rolling temperature of the universal roughing mill is 800 to 870 DEG C; and a control total rolling reduction rate of a universal rolling area is more than or equal to 50 percent. By the method, the hot rolled H-shaped steel with high strength, high toughness, high weather resistance and good welding performance can be prepared. At the same time, because the steel has simple metallurgic components, relatively low alloying production cost, economy and practicability, the hot rolled H-shaped steel is the ideal hot rolled H-shaped steel used for manufacturing railway vehicles, freight semi-trailers and other industrial facilities needing the high-strength and high-weather-resistance steel.

Description

technical field [0001] The invention relates to the field of low-alloy steel, in particular to an economical high-strength and high-weather resistance hot-rolled H-shaped steel and a rolling method thereof. Background technique [0002] High-strength weather-resistant steel refers to weather-resistant steel with a yield strength ≥ 450 MPa. This type of steel is mainly used in the manufacture of special containers, bridges and high-speed train carriages. aspects play an important role. Especially with the rapid development of the national economy, the railway transportation industry is moving towards high-speed passenger transportation and heavy-duty freight transportation, and there is an urgent need for hot-rolled H-beams with high strength, high toughness and high weather resistance. Since high weathering steel requires high weather resistance, high strength level, excellent low temperature impact toughness and welding performance, it requires high level of metallurgical ...

AI Technical Summary

Problems solved by technology

However, based on the hot-rolled H-beam rolling process, using V and Nb micro-alloying technology to produce high-strength weather-resistant hot-rolled H-beam with a yield strength of 450MPa and above has not been reported at home and abroad, especially the economical high-strength weather-resistant steel.