Reliable Hardness method on equipments

[LahaneD]

I have checked hardness of equipment after PWHT with portable hardness tester(Equotip). The thickness of CS equipment(A106 Gr B/A105) was 9.53 mm & hardness of PM was 110-115 BHN.
I thought that tensile property of equipment may have dropped down to its min requirement so I simulate a test piece.
The test piece was send to test lab for hardness check . surprisingly the hardness value were 135-140 BHN & subsequent tensile value also above the min required.
So my conclusion is that portable hardness tester is not reliable.

Can anybody suggest the reliable hardness measurement on equipment?

 

[MikeMet]

Microdur portable hardness tester. I is semi automated, has a magnetic base for reliable readings and can be attached to a printer for hard copy results.

 

[LahaneD]

MikeMet,
How much it costs, where i could get it?

 

[Guest102023]

I don't think the Equotip is suitable for heat-affected zones. The Microdur is OK, provided you have sufficient thickness that material stiffness/vibration is not an issue.

 

[LahaneD]

Brimstoner,

As the hardness reading below 12 mm thickness are not reliable by using EQUIOTIP portable hardness tester. I have proposed customer that we will put additional test piece of pipe in the PWHT cycle each time & will test it in test lab by conventional method.But customer came with question as "what about weld & HAZ hardness?".What should be the justifiable answer.
The test lab is also of same opinion that portable hardness method is not reliable below 12 mm & i always deal with thickness less than 12 mm.Please suggest the reliable method

 

[jbeckhou]

The equiotip is NEVER the same as the Brinell test. ALl has to do with surface finish.
We use a King brinell hardness tester or a pin brinell tester.

http://www.westportcorp.com/hardness/brinnell/KingBrinellPortable.htm

FYI
If you use a pin brinell tester, make sure to keep traceability on the pin material.

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