A method for producing extra-thick steel plates by one-dimensional deformation of continuous casting slabs

Abstract

The invention provides a method of producing a super-thick steel plate through one-dimensional deformation of a continuous casting billet. In the method, a 300 mm continuous casting billet is employed for producing the super-thick steel plate being less than 225 mm in thickness, wherein the total reduction rate in the thickness direction of both forging and rolling is not less than 25%. The forging heating temperature is not less than 1150 DEG C and is maintained for not less than 3 h. A WHF wide flat anvil high-temperature strong-pressure forging method is employed, wherein one-time forging amount h is not less than 40 mm. The moving speed of the anvil acting on the continuous casting billet is not less than 4 mm / s. The slow cooling time after forging is not less than 24 h. The heating temperature of rolling the billet is 1100-1250 DEG C, wherein high-pressure water for removing phosphorus is carried out before billet rolling. 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 under a low-compression ratio, so that the thickness specification of the steel is significantly enlarged and the production cost is reduced. The method increases yield and performance qualified rate of the super-thick steel plate, and can reach more than 90% in defect detection qualified rate.

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 225 mm by using 300 mm continuous casting slabs through one-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 ex...

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.