Metal treatment – Process of modifying or maintaining internal physical... – Heating or cooling of solid metal
Reexamination Certificate
2008-07-08
2008-07-08
Yee, Deborah (Department: 1793)
Metal treatment
Process of modifying or maintaining internal physical...
Heating or cooling of solid metal
C148S233000, C148S541000, C148S547000
Reexamination Certificate
active
11105795
ABSTRACT:
A welding structural steel product exhibiting a superior heat affected zone toughness, comprising, in terms of percent by weight, 0.03 to 0.17% C, 0.01 to 0.5% Si, 0.4 to 2.0% Mn, 0.005 to 0.2% Ti, 0.0005 to 0.1% Al, 0.008 to 0.030% N, 0.0003 to 0.01% B, 0.001 to 0.2% W, at most 0.03% P, at most 0.03% S, at most 0.005% O, and balance Fe and incidental impurities while satisfying conditions of 1.2≦Ti/N≦2.5, 10≦N/B≦40, 2.5≦Al/N≦7, and 6.5≦(Ti+2Al+4B)/N≦14, and having a microstructure essentially consisting of a complex structure of ferrite and pearlite having a grain size of 20 μm or less. The method includes the steps of preparing a slab of the above-described composition, heating the slab to 1,100° C. to 1,250° C. for 60-180 minutes, hot rolling the heated slab in an austenite recrystallization range at a 40% or more rolling reduction followed by controlled cooling.
REFERENCES:
patent: 3904447 (1975-09-01), Gondo et al.
patent: 6686061 (2004-02-01), Jeong et al.
patent: 6946038 (2005-09-01), Jeong et al.
patent: 6966955 (2005-11-01), Choi et al.
patent: 0 940 477 (1999-09-01), None
patent: 1 006 209 (2000-06-01), None
patent: 58-031065 (1983-02-01), None
patent: 60-245768 (1985-12-01), None
patent: 61-079745 (1986-04-01), None
patent: 61-190016 (1986-08-01), None
patent: 64-015320 (1989-01-01), None
patent: 5-186848 (1993-07-01), None
patent: 8-60292 (1996-03-01), None
patent: 08-232043 (1996-09-01), None
patent: 08-283905 (1996-12-01), None
patent: 9-194990 (1997-07-01), None
patent: 9-324238 (1997-12-01), None
patent: 10-298706 (1998-11-01), None
patent: 10-298708 (1998-11-01), None
patent: 11-092860 (1999-04-01), None
patent: 11-140582 (1999-05-01), None
patent: 2000-226633 (2000-08-01), None
patent: 2001-098340 (2001-10-01), None
patent: 1996-31635 (1996-09-01), None
Nakanishi, Mutsuo et al., “Improvement of Welded HAZ Toughness by Dispersion with Nitride Particles and Oxide Particles”,Journal of Japanese Welding Society,vol. 52, No. 2, pp. 49-56 (1983).
Maóai et al., “Influence of Welding Thermal Cycle on Second Phase Particle in TiMicroalloyed Steel”, PCTA, vol. 36, No. 6, Jun. 2000 (4 pp.), China.
Database WPI, Section Ch, Week 200329, Derwent Publications Ltd., London, Gb; Class M, p. 24, AN 2003-296924, XP002297661 & KR 2002 091 329 A (POSCO), Dec. 6, 2002, Abstract.
Choi Hae-Chang
Jeong Hong-Chul
POSCO
The Webb Law Firm P.C.
Yee Deborah
LandOfFree
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