METHOD FOR MANUFACTURING ULTRA THICK STEEL PLATE

摘要

PURPOSE: A method for manufacturing ultra thick steel plate for pressure vessel is provided to completely compress voids formed inside of the ultra thick steel plate without bal influences to the stability of rolling facilities. CONSTITUTION: In a manufacture of ultra thick steel plates having many shrinkage voids therein by hot rolling a slab, the method is characterized in that after rolling operation is conducted at an effective reduction ratio of 7 to 40 % according to thickness of final steel plate and radius of rolling rolls using rolls with a radius of 155 to 550 mm in order to obtain ultra thick steel plates with a thickness of 70 to 150 mm, the ultra thick steel plates are again rolled at final rolling process at higher than an effective reduction ratio.