Global Patent Index - EP 0974678 A1

EP 0974678 A1 2000-01-26 - Process and steel for the manufacturing of welded vessels, intended for use in the presence of hydrogen sulphide

Title (en)

Process and steel for the manufacturing of welded vessels, intended for use in the presence of hydrogen sulphide

Title (de)

Verfahren und Stahl für die Herstellung von geschweissten Behältern, bestimmt zur Verwendung in Gegenwart von Schwefelwasserstoff

Title (fr)

Procédé et acier pour la fabrication d'une enceinte chaudronnée, travaillant en présence d'hydrogène sulfuré

Publication

EP 0974678 A1 (FR)

Application

EP 99401632 A

Priority

FR 9809271 A

Abstract (en)

Steel components of the boiler enclosure are manufactured and comprise (in wt.%): 0.03-0.15 C, 0-0.5 Si, 0.4-2.5 Mn, 0.5-3 Ni, 0-1 Cr, 0-0.5 Mo, 0-0.07 Al, 0-0.04 Ti, 0-0.004 B, 0-0.02 V, 0-0.05 Nb, below 1 Cu, below 0.015 S, and below 0.03 P. Manufacturing a boiler enclosure to work under pressure between -40-200 degrees C with cracking risks under stress generated by H2S as defined by the standard specification NACE MR 0175-97 comprises manufacturing steel components of the boiler enclosure comprising (in wt.%): 0.03-0.15 C, 0-0.5 Si, 0.4-2.5 Mn, 0.5-3 Ni, 0-1 Cr, 0-0.5 Mo, 0-0.07 Al, 0-0.04 Ti, 0-0.004 B, 0-0.02 V, 0-0.05 Nb, below 1 Cu, below 0.015 S, and below 0.03 P. The chemical composition is CET = C+ (Mn+Mo)/10 + (Cr+Cu)/20 + Ni/40 below 0.35 and the critical cooling time between 800 degrees C and 500 degrees C: cct 800/500 is below 10 s. The components are quenched and tempered, after or before forming, in order to obtain a martensitic or a martensitic-bainitic structure comprising less than 10 % ferrite. After forming the components, they are relaxed at a temperature above 595 degrees C, the components are welded with an energy and pre-heating conditions such that the cooling time ct 800/500 between 800 and 500 degrees C of the heated zone is above 5 s. A post-welding thermal treatment is performed at a temperature Tpw above 595 degrees C and below 680 degrees C. The obtained steel has a tensile strength above 550 Mpa, a yield strength above 450 MPa, an elongation above 17 % and an impact strength at -40 degrees C above 40 Joules, and hardness everywhere on the surface of the enclosure below 248 HV. Independent claims are also included for (1) a boiler enclosure manufactured as above, and (2) a steel for manufacturing boiler enclosure.

Abstract (fr)

Procédé de fabrication d'une enceinte chaudronnée destinée à travailler sous pression entre - 40 °C et 200 °C en présence d'H2S dans les conditions définies par la norme NACE MR 0175-97 selon lequel : on fabrique des composants de l'enceinte en acier de composition chimique : 0,03 % <= C <= 0,15 % ; 0 % <= Si <= 0,5 % ; 0,4 % <= Mn <= 2,5 % ; 0,5 % <= Ni <= 3 % ; 0 % <= Cr <= 1 % ; 0 % <= Mo <= 0,5 % ; 0 % <= Al <= 0,07 % ; 0 % <= Ti <= 0,04 % ; 0 % <= B <= 0,004 % ; 0 % <= V <= 0,02 % ; 0 % <= Nb <= 0,05 % ; Cu <= 1 % ; S <= 0,015 % ; P <= 0,03 % ; le reste étant du fer et des impuretés résultant de l'élaboration ; CET = C + (Mn + Mo)/10 + (Cr + Cu)/20 + Ni/40 <= 0,35 ; trc 800/500 <= 10 s ; les composants étant trempés et revenus ; la structure est martensitique ou martensito-bainitique avec moins de 10 % de ferrite; la température de revenu est < 680°C. On effectue éventuellement un détensionnement à une température >= 595°C. On soude les composants dans des conditions telles que le temps de refroidissement tr entre 800 °C et 500 °C de la ZAC soit > 5 secondes, et on effectue un traitement thermique post-soudage entre 595°C et 680°C, l'acier étant tel que Rm >= 550 MPa, Re >= 450 MPa, A % >= 17 %, KCV >= 40 J à - 40°C, et la dureté en tous points de la surface de l'enceinte est <= 248 HV. Enceinte obtenue et acier.

IPC 1-7 (main, further and additional classification)

C22C 38/04; C22C 38/08; C22C 38/44; C22C 38/46

IPC 8 full level (invention and additional information)

B23K 9/23 (2006.01); B01J 3/04 (2006.01); B23K 9/00 (2006.01); C21D 9/00 (2006.01); C21D 9/08 (2006.01); C21D 9/50 (2006.01); C22C 38/00 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); C22C 38/58 (2006.01)

CPC (invention and additional information)

C21D 9/50 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/58 (2013.01); C21D 2211/002 (2013.01); C21D 2211/008 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

DOCDB simple family

EP 0974678 A1 20000126; EP 0974678 B1 20040428; AT 265553 T 20040515; CA 2278407 A1 20000121; DE 69916717 D1 20040603; DE 69916717 T2 20050504; ES 2220020 T3 20041201; FR 2781506 A1 20000128; FR 2781506 B1 20000825; JP 2000054026 A 20000222; KR 20000011781 A 20000225; US 6322642 B1 20011127