Wide weather-resistant steel for 700 MPa-level hot-rolled container and manufacturing method thereof

Abstract

The invention discloses wide weather-resistant steel for a 700 MPa-level hot-rolled container and a manufacturing method thereof. The steel contains C: 0.058%-0.078%, Si: 0.65%-0.75%, Mn: 0.65%-0.85%,P: 0.035%-0.045%, S: less than or equal to 0.006%, Al: less than or equal to 0.040%, Cr: 0.22%-0.31%, Cu: 0.11%-0.19%, Ti: 0.060%-0.075%, RE: 0.021%-0.035%, N: less than or equal to 0.005%, and the balance Fe and inevitable impurities. The outlet temperature of a billet soaking section is 1283-1300 DEG C, the holding time is 27-41 min, and the total in-furnace time is less than or equal to 178 min. Rough rolling outlet temperature is greater than or equal to 1100 DEG C, finish rolling start temperature is 1087-1108 DEG C, finish rolling finish temperature is 925-947 DEG C, a billet is cooledto 655-675 DEG C for taking up at a cooling rate of 37-47 DEG C/s, flattening force is 5500-6500 KN, and bending force is 30-40 KN. The flatness of a finished steel sheet after flattening is less thanor equal to 3 mm/m.

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 width of 700 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. If th...

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Problems solved by technology

[0007] The present invention aims to overcome the deficiencies in the prior art that the weather-resistant steel strip for 700MPa-level hot-rolled containers is high in cost and cannot be used by users due to warping after opening, and provides a weather-resistant steel for 700MPa-level hot-rolled containers with a wide width and a manufacturing method thereof , to solve the above-mentioned problems existing in the prior art

[0008] Aiming at the prominent technical problem of ship shape warping existing in the current production process of wide 700MPa container steel, the technical proposal of the present invention is specially proposed

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