Hardness&Impact test

[farzam]

Hi All,

I need some information or references about requirements of production test,such as Hardness,Impact,Bending test for pressure vessels.

Thanks alot

 

[metengr]

You can use the Google search feature in the above tool bar for each of the test methods. There is plenty of information on the internet for each type of test method.

 

[ijzer]

Production test requirements are depending on the fabrication Code. Which Code do you use for the Vessel?

 

[farzam]

Dear friends,

The code is ASME VIII,Div1, and just I wanna know for vessels under sour service production test including(impact,hardness, bending,tensile,micro&macro tests) are required or not?

Thank you so much

 

[gr2vessels]

farzam,

In Sour service the main issue is the hardness (22 HRC per NACE 0175). However, the real mechanism affecting the materials listed in NACE 0175 is similar to the hydrogen induced corrosion cracking, hence you have to consider all the hydrogen service limitations also (self reinforcing nozzles, etc..). The carbon steel materials have heavy limitations on composition also, like max. 0.23%C for plate and 0.25%C for forgings, max. 0.45% Carbon Equivalent on long formula, also some limits on the sulphur content (refer NACE 0175). This implies limits on tensile properties, preference given to lower strength materials, hence bending tests also. I believe that micro/macro tests refer to the welded structure, part of the welding procedure qualification for materials in sour service. Impact test requirements would normally refer to the low temperature applications, unless you specify some below zero hydrotesting or similar operating conditions.

Cheers,

gr2vessels