Hot-rolling high-strength weather-resistant steel and manufacturing method thereof

Abstract

The invention provides hot-rolling high-strength weather-resistant steel and a manufacturing method thereof. Chemical components of the hot-rolling high-strength weather-resistant steel comprise, by mass percentage, 0.05-0.07% of carbon, 0.5-0.6% of silicon, 0.80-1.0% of manganese, 0.03-0.07% of phosphorus, less than or equal to 0.005% of sulphur, 0.25-0.35% of chromium, 0.25-0.35% of copper, 0.09-0.11% of titanium and the balance iron and inevitable impurities. By means of the hot-rolling high-strength weather-resistant steel and the manufacturing method thereof, the ratio of nickel to copperequals to zero; in addition, technological steps are improved so that the functions of the element Ni can be replaced; the copper brittleness defect is inhibited; and good surface quality of a steelplate is guaranteed.

Description

technical field [0001] The invention relates to the technical field of steel production, in particular to a hot-rolled high-strength weathering steel and a manufacturing method thereof. Background technique [0002] At present, the material used for containers is mainly SPA-H steel with a yield strength of 355MPa. The strength level of this steel is relatively low, resulting in a relatively high dead weight of the container. The dead weight of a 20-foot container is 2.2 tons, and that of a 40-foot container is 3.6 tons. Due to the huge amount of container transportation in the world every year, the resulting fuel consumption and transportation costs during land and sea transportation are also huge, and at the same time have an impact on environmental pollution. The lightweight of containers is of great significance to the energy saving and emission reduction of automobiles and trains, the reduction of transportation costs, and the reduction of emissions. In order to meet th...

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Problems solved by technology

In addition, in order to ensure that the mechanical properties meet the requirements, a very high content of Cr element is added in the existing technology, and the Cr content control range is 2.15 to 4.0%. The very high content of Cr not only greatly increases the cost and difficulty of smelting, but also affects the forming of steel. The performance will be adversely affected; some add a certain amount of Nb element, which greatly increases the cost of the alloy, and the high-niobium steel has a large rolling force, which is not suitable for mass production of thin-gauge hot-rolled high-strength weathering steel of 550MPa and above

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