Steel plate for building structure with yield strength of 460 MPa, and manufacturing method thereof

Abstract

The present invention discloses a steel plate for a building structure with yield strength of 460 MPa, and a manufacturing method thereof. Chemical components of the steel plate comprise, by weight, 0.05-0.10% of C, 0.2-0.3% of Si, 1.40-1.60% of Mn, 0.025-0.060% of Nb, 0.015-0.030% of Ti, 0.015-0.045% of Als, one selected from 0.2-0.4% of Cr, 0.10-0.30% of Mo and 0.0010-0.0020% of B, and the balance of Fe and other inevitable impurities, wherein the impurity elements are controlled, and comprise, by weight, less than or equal to 0.015% of P, less than or equal to 0.005% of S, less than or equal to 0.0040% of [N], and less than or equal to 0.0020% of [O]. The manufacturing method comprises that: the steel billet heating temperature is 1180-1220 DEG C; at the first phase, the rolling starting temperature is 1040-1080 DEG C, and the rolling finishing temperature is 950-1000 DEG C; at the second phase, the rolling starting temperature is 920-870 DEG C, the rolling finishing temperature is controlled to 800-850 DEG C, the amount of the rolling accumulation and deformation in the recrystallization area is more than 60%; after hot rolling, a temperature waiting treatment is performed, and then a water cooling treatment is performed, wherein the temperature waiting time is more than 15 seconds, the water cooling starting temperature is 680-750 DEG C, the cooling rate is 5-9 DEG C per second, and the self-tempering temperature is 450-620 DEG C. The steel plate of the present invention has characteristics of simple chemical components, carbon equivalent less than 0.40, yield ratio less than 0.80 and simple production process.

Description

Technical field [0001] The invention relates to a 460MPa grade high-performance building structure steel plate and a manufacturing method thereof, and belongs to the field of metal materials. Background technique [0002] In recent years, with the steady growth of my country's steel output and the in-depth research of steel structure application technology, steel structures have been widely used in the construction field; the demand for high-strength, high-performance building structural steel is increasing. [0003] 460MPa is currently the highest strength grade of steel used in construction in China. The use of 460MPa steel for construction can save 10%-20% of steel consumption compared with the commonly used 345MPa grade. The market prospect is broad. In recent years, my country has begun to use 460MPa construction steel in batches in key projects such as the Bird's Nest, with good results. [0004] The domestic construction steel production of this level generally adopts low-car...

AI Technical Summary

Problems solved by technology

[0009] ①Generally adopt normalizing after hot rolling or quenching and tempering in two-phase zone, the production process is complicated and the cost is high;

[0010] ②High carbon equivalent, difficult to weld;

Images