A kind of ultra-long and thin gauge eh36 steel and its production method on coil-steel rolling mill

Abstract

The invention relates to ultra-long thin EH36 steel. Chemical components of the steel plate include, by mass, 0.05-0.09% of C, 1.20-1.60% of Mn, 0.10-0.25% of Si, 0.015-0.030% of Nb, 0.010-0.020% of Ti, 0.020-0.040% of Al, at most 0.38% of Ceq, the balance Fe and unavoidable impurity elements. The steel plate is 4.75-8mm in thickness and can reach 221m in the maximum length. The ultra-long thin EH36 steel is suitable for production of thin ultra-long rolled piece EH 36 ship plates through 150-mm billets and can be popularized to production with delivery in hot rolling and thermo mechanical control process (TMCP) states of steel ultra-thin ultra-long rolled pieces for bridges, high-rise buildings and structures with 36Kg-level yield strength.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy, and in particular relates to a method for producing super-long (150-220m) and thin-gauge (5-8mm) EH36 steel for ocean engineering on a steckel mill. Background technique [0002] Ship plate steel is an important steel material on which the development of the national economy depends. In recent years, China's shipbuilding industry has developed rapidly, and the annual shipbuilding volume has accounted for more than 10% of the world's total shipbuilding. With the rapid development of the shipbuilding industry, the demand for shipbuilding steel is also increasing, and the demand for ship plate steel, which accounts for 80% of shipbuilding materials, is growing rapidly. At present, in order to save the cost of downstream enterprises, there is a diversified demand for ship plate rolled parts. In order to maximize production efficiency, reduce costs, facilitate faster and better batching, and s...

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Problems solved by technology

The invention only mentions how to improve the strength, but does not involve the toughness which is very important to affect the steel plate

[0006] In actual production, in addition to the above-mentioned problems, there are still the following technical difficulties in the production of thin-gauge EH36 steel plates: 1. The surface quality control of coiled steel plates, and the production of ultra-long thin-gauge steel plates by furnace coil rolling. Surface defects, such as pockmarks, hemp pits, etc.; 2. The strength control of EH36 steel plate produced by low-carbon equivalent coil rolling, in order to ensure that the ship plate has good impact performance, welding performance and low cost control, and meet TMCP EH36 ship regulations Supply requirements; 3. Control of the uniformity of performance of the ultra-long and thin steel plate; 4. Positive tolerance control of the ultra-thin specification EH36 ship plate

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