Title:
MANUFACTURE OF ELECTRIC WELDED STEEL PIPE HAVING LOW YIELD RATIO
Document Type and Number:
Japanese Patent JPS61199032
Kind Code:
A
Abstract:
PURPOSE: To soften only the ferrite in a steel billet by recrystallization and to reduce the yield ratio by applying a prescribed working strain to the billet contg. prescribed percentages of C, Si and Mn so as to reduce the recrystallization temp. to the A1 transformation point or below.
CONSTITUTION: A steel billet consisting of 0.03W0.29% C, 0.05W0.25% Si, 0.8W1.9% Mn and the balance Fe is manufactured. The billet is sized at ≥7% reduction of area and held at the A1 transformation point or below for ≥1min. Only the ferrite in the steel billet is softened by recrystallization without softening the pearlite.
Inventors:
MURAYAMA HIROSHI
KONNO NAOKI
KONNO NAOKI
Application Number:
JP3865485A
Publication Date:
September 03, 1986
Filing Date:
March 01, 1985
Export Citation:
Assignee:
NIPPON STEEL CORP
International Classes:
C21D8/10; B21C37/08; (IPC1-7): B21C37/08; C21D8/10
Attorney, Agent or Firm:
Tachio Chanogi