Research on and Application of Newly-developed Manufacturing Process for Hollow Ingot for Pipe-rolling Purpose

Elaborated here in the article are the difficulties and critical technical issues as encountered with in manufacturing of the hollow ingot for pipe-rolling purpose, involving the material and structure of the mould core, the positioning device for the mould core, and the casting process for the hollow ingot. The quality of hollow ingots as produced with the new process is satisfactory to the stringent quality requirements for hollow stocks for rolled pipes. The new pipe rolling process that resulted from the said ingot manufacturing process, and involves direct use of hi-alloy steel hollow ingots is particularly suitable for producing hi-alloy steel seamless pipes with high quality, a wide size range, and a great variety of types. Thanks to the hollow ingot process, metal yield will be enhanced, and thus the operation costs reduced due to the fact that the boring process which is a must for solid ingot(or forged bloom)prior to pipe rolling is eliminated.