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:
Sep. 26, 2000
Filed:
Sep. 15, 1998
J Albert Sue, The Woodlands, TX (US);
Alysia Canson White, Kingwood, TX (US);
Zhigang Fang, The Woodlands, TX (US);
Smith International, Inc., Houston, TX (US);
Abstract
A new hardfacing composition is disclosed. In addition, a pulsed plasma transferred arc method for depositing hardfacing material with a higher content of carbide and lower dilution by a substrate metal is disclosed. The disclosed method produces a hardfacing coating which has a strong metallurgical bond to the substrate metal. The method includesthe following steps: (1) establishing a transferred plasma arc between an electrode and an area of a work piece, (2) optionally preheating the work piece to at least 250.degree. F., (3) forming a plasma column of inert gas in the arc by passing an electrical current between the electrode and the work piece, (4) feeding a stream of hardfacing material in powder form into the plasma column, and (5) pulsing the current between a pre-selected high pulse current value and low pulse current value while feeding the powdered hardfacing material. In this method, the low pulse current is selected to be sufficiently high to melt at least one component of the hardfacing material. The pulse rate and the high pulse current are selected to minimize the formation of a weld pool on the metal substrate during the hardfacing process. This method has applications in hardfacing any metallic work piece which requires wear resistance or erosion resistance. This method is especially effective in hardfacing roller cone surfaces and the milled teeth of a rock bit for erosion and wear protection.