Wide heavy standard high strength ship plate steel and technique for producing the same

Abstract

The invention relates to high-strength steel and a process for producing the same. The components of high-strength ship plate steel by width-thickness specification are as follows: 0.04 to 0.16 percent of C, 1.20 to 1.60 percent of Mn, less than or equal to 0.025 percent of P, less than or equal to 0.025 percent of S, 0.10 to 0.30 percent of Si, less than or equal to 0.40 percent of Ni, 0.020 to 0.060 percent of Alt, 0.02 to 0.05 percent of Nb, less than or equal to 0.02 percent of Ti, less than or equal to 0.012 percent of N, and the balance being Fe. The temperature in a smelting and heating furnace is between 1180 and 1220 DEG C, and the heating time is between 3.0 and 4.0 hours; the starting temperature for rough rolling is between 1080 and 1120 DEG C, and the rough rolling is performed for 4 to 6 times; the starting temperature for finish rolling is between 800 and 900 DEG C, and the finish rolling is performed for 4 to 9 times, and the finishing temperature is between 800 and 830 DEG C; and the starting water spray cooling temperature for cold control is between 780 and 820 DEG C, and the finishing water spray cooling temperature is between 600 and 720 DEG C. The invention has the advantages of simple process, high production efficiency, stable product performance, and mall quality fluctuation.

Description

technical field [0001] The invention relates to a high-strength steel and its production process, in particular to wide and thick high-strength ship plate steel and its production process. Background technique [0002] The price of marine steel accounts for about 15-20% of the cost of shipbuilding production, and more than 70% of the supply price of ship raw materials. The steel products demanded by the shipbuilding industry mainly include plates, profiles and pipes, among which plates are the main products. With the substantial increase in shipbuilding output and the requirements for large-scale, lightweight, specialized and high-tech ships, the development trend of shipbuilding steel in the future is: the demand for low-alloy high-strength steel will increase significantly; The board will be larger; the specifications and dimensional accuracy will be higher; the quality will be further improved, and the variety will increase. [0003] At present, several different method...

AI Technical Summary

Problems solved by technology

Due to the strict requirements on various properties of wide and thick high-strength ship plate steel, the design of its chemical composition will bring many difficulties, and many tests are required to confirm it, which greatly restricts the pace of product upgrading of ship plate manufacturers.

The production of high-strength ship plate steel with wide and thick specifications is thick and large in size, so it is easy to produce uneven structure, especially the structure in the thickness direction is difficult to control, resulting in different properties between the surface and core of the steel plate, and poor low-temperature toughness of the steel plate ; and it is easy to deform, especially in the width direction, it is difficult to control the shape of the plate, so it will cause a large deviation in the size of the steel plate

And because the production process of controlled rolling and controlled cooling is complex, the production process is complicated, and the control requirements for steel plates are strict, especially the rolling deformation and water spray cooling process need to be precisely controlled, so the qualified product rate of products will be low and the product quality will fluctuate. Large, low production efficiency and other issues

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