Continuous annealing process of deep drawing and extra-deep drawing steel plates

Abstract

The invention relates to a continuous annealing process of deep drawing and extra-deep drawing steel plates. The steel plate is washed before annealing to cause the contents of rolling oil and iron power on the surface of the steel plate are less than 20mg / m; the steel plate is put into a continuous annealing furnace and walks at the speed of 150-350m / min, mixed gas of nitrogen and hydrogen is used to blow the surface of the steel plate to protect and prevent the steel plate from oxidation, and the steel plate is heated to 120-180DEG C; and then the steel plate is heated again to 750-880 DEG C and the heat is preserved for 40-70 S; then, the steel plate is cooled to 400-460 DEG C and the heat is preserved for 60-300 S to carry out overaging treatment; finally, the steel plate is cooled to normal temperature. Owing to the employment of overaging annealing process, carbide in the steel is fully precipitated, thus guaranteeing the needs of drawing properties and extra-deep drawing properties of plates for household electrical appliances and of automobile plates.

Description

Technical field: [0001] The invention relates to a technology for heat treatment of steel plates, in particular to a continuous annealing technology for deep-drawn and ultra-deep-drawn steel plates. Background technique: [0002] In recent years, with the rapid development of China's national economic construction, the iron and steel industry has achieved world-renowned achievements, and the market demand for high-performance, high-precision cold-rolled thin plates (such as home appliance plates, automobile plates, etc.) has continued to increase. However, in the previous heat treatment process, these plates were mainly produced by bell annealing. This system has disadvantages such as low production efficiency, high energy consumption, and poor furnace temperature uniformity, so that some properties of heat-treated steel plates cannot reach the performance of home appliance plates, automobile plates, etc. Compared with the industrially developed countries in the world, there i...

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Problems solved by technology

[0002] In recent years, with the rapid development of China's national economic construction, the iron and steel industry has achieved world-renowned achievements, and the market demand for high-performance, high-precision cold-rolled thin plates (such as home appliance plates, automobile plates, etc.) has continued to increase. However, in the previous heat treatment process, these plates were mainly produced by bell annealing. This system has disadvantages such as low production efficiency, high energy consumption, and poor furnace temperature uniformity, so that some properties of heat-treated steel plates cannot reach the performance of home appliance plates, automobile plates, etc. Compared with the industrially developed countries in the world, there is still a certain gap in the quality of sheet metal. Therefore, for a long time, my country's high-quality precision sheet metal has been imported, or replaced by sheets produced in my country, which has reduced the quality of our country. Quality of Home Appliances and Cars

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