Patent ID: 8770003
Filing Date: 2014-07-08
Classification: B21B

Abstract:
1. A method for producing a seamless pipe comprising steps of a billet-heating process, a billet-cutting process, a piercing-rolling process and elongation-rolling process, wherein: the method using the billets satisfying the following formulas (1) to (3): wherein L is the length (m) of the parent billet and is represented by the following formula (4), and F is the billet-heating-furnace filling factor (%) and is represented by the following formula (5): wherein in the above-described formulas, the meanings of the individual symbols are as follows: L L l: The length (m) of the child billet l l k: Billet cutting margin (m) n F wherein, the method adopts the following respective values in the following respective cases (A) to (C) in each of which the relation between the number-of-obtainable-billet indexes I (A) A case where I L obtained by substituting n (B) A case where I L obtained by substituting n (C) A case where I L wherein Int(X) means the maximum integer that does not exceed the specified numerical value X.