Big-thickness slab manufacturing technique

The invention discloses a big-thickness slab manufacturing technique belonging to the technical field of ferrous metallurgy. According to the technique, more than two continuous casting slab blanks are overlapped, and then the four sides of the blanks are combined and welded by using a combined welding technique of gas shielded welding, submerged-arc welding and electron-bombardment welding so as to form one big-thickness slab. The invention breaks through the limit of complex manufacturing process, no guarantee in inner quality or low production efficiency in the traditional big-thickness slab manufacturing technique and provides a method for producing a big-thickness slab with high quality and high efficiency by using the traditional continuous cast slab blanks, and the method is simple in operation, small in investment, high in production efficiency, flexible in organization form, capable of well satisfying the requirement of a raw material used for producing the big-thickness slab with high piece weight and high compression ratio and realizing mass industrial production, and especially suitable for the production of the big-thickness slab with the thickness of more than 600mm, and is widely applied to the manufacturing of high-quality super-thick steel plates used for various important technique equipment.