Weather-resistant steel for hot-rolled container with width of 450 MPa and manufacturing method of weather-resistant steel

Abstract

The invention discloses weather-resistant steel for a hot-rolled container with the width of 450 MPa and a manufacturing method of the weather-resistant steel. The steel contains 0.048%-0.065% of C, 0.61%-0.70% of Si, 0.35%-0.45% of Mn, 0.075%-0.085% of P, smaller than or equal to 0.006% of S, smaller than or equal to 0.040% of Al, 0.20%-0.29% of Cr, 0.11%-0.19% of Cu, 0.035%-0.050% of Ti, 0.010%-0.025% of RE, smaller than or equal to 0.004% of N and the balance iron and inevitable impurities. The outlet temperature of a soaking section of the casting blank is 1278-1298 DEG C, the heat preservation time of the soaking section is 23-37 min, and the total in-furnace time is smaller than or equal to 170 min; the rough rolling outlet temperature is larger than or equal to 1100 DEG C, the finish rolling initial rolling temperature is 1075-1093 DEG C, the finish rolling final rolling temperature is 915-938 DEG C, cooling is conducted to 646-665 DEG C at the cooling speed of 31-41 DEG C / s, coiling is conducted, the leveling force is 4500-5500 KN, and the roll bending force is 10-20 KN.The straightness of the steel strip is smaller than or equal to 3 mm / m. good corrosion resistance is achieved.

Description

technical field [0001] The invention belongs to the field of steel for containers, and relates to a weather-resistant steel for hot-rolled containers with a wide width of 450 MPa and good flatness. Background technique [0002] The traditional 20-foot and 40-foot ordinary containers use SPA-H with a yield strength of 345MPa, which has low material strength and high consumption. In the field of container manufacturing, my country is gradually promoting the application of 450-700MPa high-strength steel plates. Compared with the steel used in ordinary standard containers, the use of high-strength steel plates can reduce the weight by 15% to 40%, which can save a lot of transportation costs. Due to its special purpose, the container has high requirements on the material of the steel. In addition to having good atmospheric corrosion resistance and high plasticity, the flatness of the steel strip after flattening is better, especially for the steel with a higher strength level. ...

AI Technical Summary

Problems solved by technology

[0007] The present invention aims to overcome the deficiencies in the prior art that the weather-resistant steel strip for 450MPa-level hot-rolled containers is high in cost and the user cannot use it due to warping after leveling, and provides a weather-resistant steel for 450MPa-level hot-rolled containers with a wide width and a manufacturing method thereof , to solve the above-mentioned problems existing in the prior art

[0009] Aiming at the prominent technical problem of warpage of the ship shape existing in the current production process of wide 450MPa container steel, the technical proposal of the present invention is specially proposed

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