The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1996
Filed:
Feb. 08, 1995
Joseph E McVicker, Chillicothe, IL (US);
Caterpillar Inc., Peoria, IL (US);
Abstract
A high toughness steel has a composition comprising, by weight, about 0.10% to 1.05% carbon, about 0.00% to 0.05% aluminum, about 0.01% to 0.20% titanium, about 0.0005% to 0.02% boron, about 0.01% to 0.20% niobium and about 0.015% to 0.04% nitrogen and the balance essentially iron. Also, the composition contains sufficient amount of manganese, silicon, nickel, chromium, vanadium, and molybdenum such that said high toughness steel article, after quenching and tempering, has a R.sub.c hardness measured in the middle of a section having a thickness of no more than 25.4 mm, of at least 50% of the hardness measured at the surface of said section. After quenching and tempering, steel articles made of this composition have a plane strain fracture toughness more than 25% higher than that for steel having the same base chemistry and heat treatment, and being free from titanium, niobium, and boron and elevated nitrogen. Also, the composition preferably contains about 0.001% to 0.004% oxygen and less than about 0.04% each of phosphorous and sulfur. A high toughness steel embodying the present invention is particularly useful for making ground engaging tools that are constantly subjected to severe impact and vibration and are susceptible to breakage.