Method for applying protective coatings

• US 4,663,181 A
• Filed: 02/24/1986
• Issued: 05/05/1987
• Est. Priority Date: 02/24/1986
• Status: Expired due to Fees

• Current Assignee: Conoco Incorporated (ConocoPhillips)
• Original Assignee: Conoco Incorporated (ConocoPhillips)
• Inventors: Murali, Jagannathan
• Primary Examiner(s): BECK, SHRIVE
• Application Number:
  US06/832,098
• Time in Patent Office: 435 Days
• Field of Search: 427/34, 427/423, 427/409, 204/192 N, 204/192 C
• US Class Current: 427/456
• CPC Class Codes: C23C 28/00 Coating for obtaining at least two superposed coatings either by methods not provided for in a single one of groups C23C2/00 - C23C26/00 or by combinations of methods provided for in subclasses C23C and C25C or C25D
• CPC Class Codes: C23C 28/023 only coatings of metal elements only
• CPC Class Codes: C23C 4/02 Pretreatment of the material to be coated, e.g. for coating on selected surface areas

Abstract

Flame sprayed aluminum coatings have been shown to be of excellent value in providing cathodic protection to steel structures in a marine environment. The common method of applying flame sprayed aluminum to a steel substrate comprises providing an anchor pattern to the substrate. Such anchor pattern can result in fatigue cracking of the substrate developing within the surface discontinuities of the anchor pattern. The present invention provides a method for providing a layered, ion sputtered aluminum base coating of the substrate to which a flame sprayed aluminum coating may adhere without the need for a roughened surface on the substrate with its consequent potential for reduction of fatigue strength.

Claims

1. In a method for applying a flame sprayed aluminum coating to a steel substrate, the improvement which comprises applying an ion sputtered aluminum layer to said substrate prior to the application of said flame sprayed aluminum coating.

2. The improvement as set forth in claim 1 wherein said step of applying the ion sputtered aluminum layer is carried out to apply a thickness of 10 to 20 micro-meter of aluminum.

3. The improvement as set forth in claim 1 further including the step of applying an antifoulant sealant coating to the flame sprayed aluminum coating.

4. The improvement as set forth in claim 3 wherein the step of applying an antifouling sealant coating comprises applying a vinyl based sealant containing antifoulant particles selected from the group consisting of cuprous oxide, tributyl tinoxide, and combinations thereof.