Method of producing super-thick steel plate through three-dimensional deformation of continuous casting billet

Abstract

The invention provides a method of producing a super-thick steel plate through three-dimensional deformation of a continuous casting billet. In the method, the total reduction rate in the thickness direction of both forging and rolling is not less than 23%. The continuous casting billet is forged through a technology including three directions of length, width and thickness, wherein the continuous casting billet is firstly forged in the length direction, then is forged in the width direction and is finally forged in the thickness direction. One-time forging amounts in the length direction and the width direction are 120-230 mm and the one-time forging amount in the thickness direction is not less than 50 mm. The slow cooling time after forging is not less than 48 h. The heating temperature of rolling the billet is 1100-1250 DEG C. The roll beginning temperature is higher than 1050 DEG C. The slow cooling temperature after forging is not less than 400 DEG C and the slow cooling time is not less than 24 h. The method achieves production of the super-thick steel plate being not more than 270 mm in thickness at a low compression ratio with the continuous casting billet, wherein the steel plate can reach standard requirements in performances and is not less than 90% in defect detection qualified rate. The size range of the steel plate is effectively increased. The method allows accurate production aiming to the size of the steel plate, wherein the length, the width and the thickness are accurately controlled, thereby increasing the yield of the steel plate.

Description

technical field [0001] The invention belongs to the field of metal material pressure processing, in particular to a method for producing extra-thick steel plates below 270 mm by using 300 mm continuous casting slabs through three-dimensional deformation. Background technique [0002] In recent years, with the rapid development of my country's heavy industry, transportation, and national defense modernization, the demand for extra-thick steel plates in industries such as energy, transportation, construction, shipbuilding, and machinery manufacturing is increasing. On the basis of the existing thickness specifications, the extra-thick steel plate puts forward higher requirements for the internal quality of the steel plate, which is reflected in the increasingly strict requirements for the performance and flaw detection level of the steel plate. At the same time, the increase in production enterprises and capabilities of extra-thick steel plates has made the competition in the ...

AI Technical Summary

Problems solved by technology

At present, three production processes are widely used in the production of extra-thick plates: one is the direct rolling of continuous casting slabs. This method is limited by the compression ratio and the thickness of continuous casting slabs. The general product thickness is less than 200mm, and the thickness ranges from 100 to 200mm. Performance pass rate and flaw detection rate are not high

The second is to use steel ingots for direct rolling. Generally, the thickness of the steel plate produced is more than 150mm. This method can increase the thickness of the finished steel plate and increase the compression ratio, but the production cost is significantly higher than that of the continuous casting slab.

The third method uses steel ingots to be rolled after processing (including forging, secondary blanking, electroslag remelting, etc.), and this method will also significantly increase production costs

However, the above production methods for extra-thick steel plates all have a common defect, that is, the production cost is relatively high, which is unbearable for thick plate manufacturers.

[0005] To sum up, the current production method of extra-thick steel plate (thickness above 100mm) cannot achieve the goal of low cost and high pass rate, and the width of the produced steel plate is limited by the blank specification, which is not suitable for the production of narrow steel plate, and the production method not flexible enough