A kind of q345 grade hot-rolled weather-resistant large-scale angle steel for iron tower and its preparation method

Abstract

The invention provides a Q345-grade hot-rolled weather-resistant large-scale steel angle for an iron tower and a preparation method thereof. The q345-grade hot-rolled weather-resistant large-scale steel angle comprises the following components, by weight, 0.03%- 0.10% of C, 0.15%-0.50% of Si, 0.30%-0.90% of Mn, less than or equal to 0.020% of P, less than or equal to 0.015% of S, 0.40%-0.80% of Cr, 0.10%-0.30% 0f Ni, 0.20%-0.50% of Cu, more than or equal to 0. 015% of Als, 0.01%-0.05% of Ti, 0.03%-0.10% of V and the balance Fe. The invention further provides a preparation method of the Q345-grade hot-rolled weather-resistant large-scale steel angle for the iron tower. The method has the advantages that a component design scheme of low C, V and Ti composite additive and a proper amount of corrosion-resistant elements is adopted, the Q345-grade hot-rolled weather-resistant large-scale steel angle for the iron tower with atmospheric corrosion resistance can be produced in batches under the condition of existing steel angle production equipment.

Description

technical field [0001] The invention relates to the field of metallurgy, in particular to a Q345 grade hot-rolled weather-resistant large angle steel for iron towers and a preparation method thereof. Background technique [0002] For a long time, my country's transmission line towers have mainly used hot-rolled angle steel profiles, supplemented by a small amount of steel pipes as tower materials. The main types of steel materials are Q235B, Q345B / C and Q420B / C. In recent years, under the vigorous promotion of the State Grid Corporation of China, high-strength steel and steel pipe towers have been widely used in transmission line towers, and the application of high-strength bolts, cold-formed steel and composite materials has also entered the stage of gradual exploration and use. During the manufacturing process of transmission towers made of carbon steel and low-alloy structural steel, hot-dip galvanizing is used for anti-corrosion. Galvanized anti-corrosion requires speci...

AI Technical Summary

Problems solved by technology

Such defects make the steel plate affected in the subsequent use process, and its corrosion resistance and welding performance are reduced

Another type of defect is 90° cold-bending cracking. After the hot-rolled weather-resistant steel plate is cold-bent and deformed, cracks appear at the corners, which makes the weather-resistant cold-formed angle steel transmission tower unable to be deployed on a large scale.

In addition, it needs to go through the cold forming process, which increases the cost, and it is difficult to cold form large-size angle steel

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