EP 0320548 B1 19920812 - METHOD OF MAKING A DUPLEX STAINLESS STEEL AND A DUPLEX STAINLESS STEEL PRODUCT WITH IMPROVED MECHANICAL PROPERTIES
Title (en)
METHOD OF MAKING A DUPLEX STAINLESS STEEL AND A DUPLEX STAINLESS STEEL PRODUCT WITH IMPROVED MECHANICAL PROPERTIES
Publication
Application
Priority
EP 87311114 A 19871217
Abstract (en)
[origin: EP0320548A1] There is disclosed a method of making a duplex stainless steel for an alloy having the following composition: Carbon 0.001 to 0.08 Wt.% Manganese 0.001 to 2.00 Wt.% Silicon 0.001 to 1.50 Wt.% Chromium 20.00 to 27.50 Wt.% Nickel 8.00 to 11.00 Wt.% Molybdenum 3.00 to 4.50 Wt.% Sulfur 0.0001 to 0.050 Wt.% Phosphorus 0.0001 to 0.050 Wt.% Nitrogen 0.10 to 0.30 Wt.% Iron Balance by selecting a heat treating temperature in the range of about 2050 DEG F to about 2350 DEG F to provide a desired impact toughness and a desired yield strength. There is also disclosed a duplex stainless steel having austenite pools in a ferrite matrix resulting from heating to a temperature in the range of 2050 DEG F - 2350 DEG F and cooling rapidly thereafter, said steel having essentially the above-mentioned composition with the proviso that <MATH> where: Creq = 1.5 (%Cr+%Si+%Mo) Nieq = %Ni+0,3 (%Mn) +%Cu+22(%C) +5%N and having greater impact toughness values in the cast form than Ferralium Alloy 225 and SAF 2205, the impact toughness in Charpy V-notch testing at -100 DEG F being above 75 ft.-lbs. when tested from keel blocks per ASTM E23-82, the HAZ impact toughness at -100 DEG F being above about 50 ft.-lbs. and having a yield strength of at least 65 KSI.
IPC 1-7
IPC 8 full level
C22C 38/00 (2006.01); C22C 38/44 (2006.01)
CPC (source: EP)
C22C 38/001 (2013.01); C22C 38/44 (2013.01)
Designated contracting state (EPC)
DE FR GB SE
DOCDB simple family (publication)
EP 0320548 A1 19890621; EP 0320548 B1 19920812; DE 3781160 D1 19920917; DE 3781160 T2 19930318
DOCDB simple family (application)
EP 87311114 A 19871217; DE 3781160 T 19871217