Forging-and-rolling compounded forming method for comprehensively promoting internal and external quality of wide and thick plate blanks

Abstract

The invention belongs to the field of pressure processing of steel materials, particularly relates to a forging-and-rolling compounded forming method for comprehensively promoting internal and external quality of wide and thick plate blanks. Numerical simulation technique is adopted to study internal strain distribution of the plate blanks formed by pure rolling, pure forging and the forging-and-rolling compounded forming method, and the forging-and-rolling forming method is provided and includes steps of 1), firstly heating the plate blanks to be cast; 2), subjecting the plate blanks to forging and deforming in a large hydraulic press after heating the same; 3), returning the plate blanks to be forged in a heating furnace for heat preservation after forging and deforming; and 4), delivering the forged plate blanks in a heated manner to a rolling mill to be rolled after heat preservation or cooling the same slowly to room temperature prior to being heated and rolled again. The forging-and-rolling compounded forming method has the advantages that the forging-and-rolling compounded forming method is applicable to forming process of various molded wide and thick plate blanks (slab ingot), especially to blanks with central looseness; by the method, the defect of core density loose of the wide and thick plate blanks can be overcome, micro-segregation can be alleviated, and texture of the plate blanks can be refined and distributed well; and meanwhile, surface quality of the steel plates can be guaranteed, working allowance can be reduced, and the finished wide and thick plate blanks with 'internal solidness and external refinement' can be realized.

Description

technical field [0001] The invention belongs to the field of pressure processing of iron and steel materials. Specifically, it adopts a compound forming method of forging and rolling to improve the internal and external comprehensive quality of wide and thick slabs. It is suitable for various die-casting of wide and thick slabs (slabs) forming process. Background technique [0002] Large wide and thick plates are the basic base material of major projects, and their application scope covers petrochemical pressure vessels, high-end molds, marine engineering, metallurgical machinery, bridge construction and other civil and national defense fields. According to conservative estimates, the current market demand for extra thick plates in my country is 500 More than 10,000 tons per year, the annual output value is nearly 100 billion. Due to the limitations of equipment capacity and technical level, my country's extra-thick steel plates have always relied on imports from Germany's D...

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Problems solved by technology

However, although the size of the porosity is reduced, it is more finely dispersed. These micro porosity and micro segregation coexist, and it is difficult to completely eliminate them in the casting process.

After the casting slab adopts the ordinary rolling process, it is often found that there are point defects on the section ( Figure 11 shown), affecting the mechanical properties of the steel, such dense defects generally exist inside the steel plate (distributed as Figure 12a ~ Figure 12b shown), in severe cases, it will lead to failure of flaw detection and scrap

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