Is HVOF Spray Coating considered as Weld Overlay

[bmoorthy]

We have many components that require HVOF (Wear resistance coating) on Presure boundry (Alloy steel components).

The question is:
1) Is HVOF considered as Welding / Weld Overlay

2) Can or should we apply QW 216 and other applicable sections (For hard Faceing overlay)of ASME Sec IX [which refers to thermal spray] for HVOF process

3)What are the qualification tests for HVOF

4) Should we expect (Only from Code prespective) a qualification for HVOF, if applied on pressure boundry?

 

[SJones]

1) No.

2) You can but it is not recommended (see 3)

3) Review ISO 14922 (all parts), ISO 14921, and ISO 14918

4) You should expect it from a quality assurance perspective

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdoweb/

 

[metengr]

Agree with SJones, the ASME B&PV Code does not recognize barrier coatings (there is no melting or fusion of filler or base metals).