×

Plug and mandrel bar for seamless steel pipe rolling operation for manufacturing seamless steel pipe

  • US 6,202,463 B1
  • Filed: 01/15/1999
  • Issued: 03/20/2001
  • Est. Priority Date: 12/27/1996
  • Status: Expired due to Fees
First Claim
Patent Images

1. A bullet-shaped plug for rolling a seamless steel pipe, the plug being used for punching a hole in a steel piece or adjusting an inner diameter or an outer diameter of a punched raw pipe, the plug comprising:

  • an extremity end part;

    a work part;

    a reeling part; and

    a parallel part, wherein at least a surface layer of the extremity end part and at least a surface layer of the work part are made of ceramic material, the surface layer of the extremity end part being at least 3 mm thick, wherein the extremity end part, the work part and the reeling part are integral, and wherein said ceramic material has a bending strength of 400 MPa or more at a temperature of 1200°

    C.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×