	US 12,473,619 B2
	Low phosphorus, zirconium micro-alloyed, fracture resistant steel alloys
Algirdas Underys, Arlington Heights, IL (US); Benjamin Ritchey, Chicago, IL (US); and Jesse Adamson, Chicago, IL (US)
Assigned to A. Finkl & Sons Co., Chicago, IL (US)
Filed by A. Finkl & Sons Co., Chicago, IL (US)
Filed on Dec. 6, 2019, as Appl. No. 16/706,320.
Claims priority of provisional application 62/777,464, filed on Dec. 10, 2018.
Prior Publication US 2020/0190641 A1, Jun. 18, 2020
Int. Cl. C22C 38/02 (2006.01); C21D 8/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/10 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/18 (2006.01)

CPC C22C 38/08 (2013.01) [C21D 8/021 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/10 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/18 (2013.01)]

14 Claims

1. An article of a steel alloy produced in a high volume electric furnace comprising:

0.36% to 0.60% by weight carbon;

0.30% to 0.70% by weight manganese;

0.001% to 0.017% by weight phosphorus;

0.15% to 0.60% by weight silicon;

1.40% to 2.25% by weight nickel;

0.85% to 1.60% by weight chromium;

0.70% to 1.10% by weight molybdenum;

0.010% to 0.030% by weight aluminum;

0.001% to 0.050% by weight zirconium;

0.001% to 0.012% by weight phosphorus;

a maximum of 0.025% by weight sulfur;

a balance of iron; and

the article having a cross-sectional thickness of 20 inches or more, a transverse impact strength of 24 ft-lb, and a surface hardness range of 363-413 HBW.