MANUFACTURE OF REACTION PIPE FOR PETROCHEMICAL PLANT

摘要

PURPOSE:To obtain a pipe body having several characteristic properties such as creep strength, formability, resistance to carburizing, and excellent homogeneity, by applying electromagnetic agitation to an inside unsolidified phase while casting a long-sized, solid, cylindrical, heat-resisting-steel body by a horizontal continuous casting. CONSTITUTION:Molten metal M is continuously charged from a holding vessel 1 into a die 2 having a cooling mechanism 5 and is quenched by the die 2 to form a solidifed shell S, and is drawn out while keeping its inside in a molten state, and electromagnetic agitation is simultaneously applied to the unsolidified phase by an electromagnetic agitating device 4. In this way, a round bar is obtained, which consists of an isometric structure (b) formed in a comparatively wide region of its inside of the outer layer (a) having a columnar structure. The ratio of the columnar structure to the isometric one in this round bar is made, i.e. the region covered by the isometric structure in the cross section of a pipe after boring the inner diameter of the bar is about 20-60% (areal percentage).