Global Patent Index - EP 0178334 A1

EP 0178334 A1 19860423 - Martensitic stainless steels for seamless steel pipe.

Title (en)

Martensitic stainless steels for seamless steel pipe.

Title (de)

Rostfreie martensitische Stähle für nahtlose Rohre.

Title (fr)

Aciers inoxydables martensiques pour tubes d'acier sans soudure.

Publication

EP 0178334 A1 19860423 (EN)

Application

EP 84112233 A 19841011

Priority

EP 84112233 A 19841011

Abstract (en)

Martensitic stainless steels that enable the fabrication of high-strength seamless steel pipe suited for use in oil-well pipe and pipeline tubing by means of a Mannesmann plug mill or Mannesmann mandrel mill process, without the formation of defects during production. The heat workability of these steels, which contain no more than 0.30% by weight of carbon and from 11 to 14% by weight of chromium, and have a ferrite content of a least 40% at 1200 DEG C, has been vastly improved by holding the phosphorus and sulfur levels therein to no more than 0.020% and 0.003% by weight, respectively. Optional elements are nickel, copper, molydenum, columbium, vanadium, calcium and rare elements. Boron may be present from 0.001 to 0.008 % by weight, aluminium from 0.005 to 0.10 % by weight.

IPC 1-7

C22C 38/18; C22C 38/38

IPC 8 full level

C22C 38/18 (2006.01); C22C 38/38 (2006.01)

CPC (source: EP)

C22C 38/18 (2013.01); C22C 38/38 (2013.01)

Citation (search report)

Designated contracting state (EPC)

DE FR

DOCDB simple family (publication)

EP 0178334 A1 19860423; EP 0178334 B1 19900718; DE 3482772 D1 19900823

DOCDB simple family (application)

EP 84112233 A 19841011; DE 3482772 T 19841011