Hot-rolled weathering angle steel with good low-temperature toughness and production method thereof

Abstract

The invention discloses a hot-rolled weather-resistant angle steel with good low-temperature toughness and a production method thereof, and relates to the technical field of iron and steel smelting. Its chemical composition and mass percentage are as follows: C: 0.05%-0.15%, Si: 0.15%-0.50%, Mn: 0.80%~1.50%, P: 0.008%~0.015%, S≤0.005%, Nb: 0.010%~0.050%, Ti: 0.010%~0.020%, Ni: 0.25%~0.45%, Cr: 0.40%~ 0.60%, Cu: 0.25% to 0.45%, Mo: 0.10% to 0.3%, Al: 0.015% to 0.050%. Designed with low-carbon components and delivered by controlled rolling and controlled cooling process, the hot-rolled weather-resistant angle steel products with good low-temperature toughness are obtained, with low carbon equivalent, good welding performance and corrosion resistance.

Description

technical field [0001] The invention relates to the technical field of iron and steel smelting, in particular to a hot-rolled weather-resistant angle steel with good low-temperature toughness and a production method thereof. Background technique [0002] The appearance of angle steel can be traced back to 1870. A steel with a carbon content of 0.64% to 0.9%, a chromium content of 0.54% to 0.68%, a tensile strength of 685MPa, and an elastic limit of 410MPa was applied to engineering structures and built a span of 158.5m. arched bridge. At present, ordinary angle steel is mainly used to make frame structures, such as towers for high-voltage power transmission, frames on both sides of steel structure bridge girders, columns and arms of tower cranes on construction sites, columns and beams in workshops, etc. Small Places such as a shelf in the shape of a flower pot on the side of the road during festivals, a shelf for air-conditioning and solar energy hanging under the window, ...

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Problems solved by technology

Patent CN107502835A discloses a high-strength and high-toughness weather-resistant angle steel for iron towers and its preparation method. It is designed with low-carbon manganese (appropriate amount of chromium-nickel-copper) and supplemented with micro-alloying elements Nb / V / Ti-N composite strengthening as the core, but the weather-resistant The low-temperature impact toughness of angle steel at -40°C is between 25-60J, which does not reach the level of -40°C low-temperature impact toughness of 100-200J, and it is designed for nitrogen-rich components, which is prone to produce subcutaneous bubbles and cracks, which may easily lead to poor casting low rate

Patent CN109487164A discloses a hot-rolled weather-resistant angle steel with a yield strength of 420MPa for iron towers and its production method. It is designed with low-carbon manganese (appropriate amount of chromium-nickel-copper) and supplemented with micro-alloying elements V-N as the core. It is displayed at 0°C and It has good impact toughness at room temperature, and there is no data showing that it has good low-temperature impact toughness at -20°C and -40°C. It only shows that the weather-resistant angle steel has reached the quality grade of B grade, and the composition design is also nitrogen-enriched. It is easy to produce subcutaneous air bubbles and form cracks, which will easily lead to low yield of slab

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