Economical high-strength high-weatherability hot-rolled H beam steel containing vanadium and nitrogen and rolling method thereof

Abstract

The invention discloses a economical high-strength high-weatherability hot-rolled H beam steel containing vanadium and nitrogen, the weight percentages (wt percent) of chemical composition are as follows: 0.07 percent to 0.12 percent of C, 0.30 percent to 0.55 percent of Si, 1.30 percent to 1.55 percent of Mn, 0.020 percent to 0.045 percent of P, 0.001 to 0.010 percent of S, 0.25 percent to 0.35 percent of Cu, 0.20 percent to 0.30 percent of Cr, 0.15 percent to 0.30 percent of Ni, 0.07 percent to 0.12 percent of V, 0.010 percent to 0.015 percent of N and 0.006 percent to 0.030 percent of Als, and the rest is iron and residual trace impurities. The invention also discloses a rolling method for the H beam steel; the cast slab-soaking temperature is 1190 DEG C to 1050 DEG C; and the finish rolling temperature of a universal finishing mill is 800 DEG C to 870 DEG C. By the method, a hot-rolled H beam with high strength, high tenacity, high weatherability and good welding performance can be obtained. Meanwhile, since the metallurgical composition of the steel is simple, the alloying production cost is low, the steel is economical and practical, and the hot-rolled H beam is an ideal hot-rolled H beam for the production of railway vehicles and freight semitrailers and the construction of other industrial facilities needing the height-strength and weatherable 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

Due to the very uneven rolling deformation of H-shaped steel, mixed crystals are very easy to appear when rolling vanadium-nitrogen micro-alloyed weathering steel, resulting in low low-temperature impact toughness, so it is necessary to adopt new designs and processes in metallurgical composition design and p