A-36 Brittle Fracture Question

[jdog1]

For a recent job, the customer statement of work specified:

"The equipment shall be designed to be operated outside for up to 3 years in temperatures ranging from 0F to 120F. Brittle fracture of the equipment must be addressed"

The statement about brittle fracture has left me somewhat befuddled. The equipment is a material handling device that is made of A-36. I thought of using ASME Section 8 Div. 1 of the Boiler and Pressure Vessel Code. It shows the allowable stress for a temperature range. In the case of A-36, the allowable stress is the same within the customer specified temperature range, I'm just not sure that allowable stress adequately addresses brittle fracture. I also found a Charpy impact exemption curve in there that I could possibly use. The problem is the requirements in the BVPC are specific to pressure vessels.

How should I address this issue?

What are some othe good references I could use?

 

[metengr]

Allowable stress and brittle fracture are not the same. You can order ASME SA 36 material with Supplementary Requirement (S5) for impact testing. In this case, at 0 deg F, you should have at least 25 ft-lbs to address "brittle fracture concerns".

 

[stanweld]

You need to take into consideration the stress application (static, dynamic, cyclic/fatigue) in your design at 0 F. In addition to metengr's recommendations, you need to consider weld joint design, weld inspection requirements, welding filler metals, need for post weld stress relief heat treatment, etc.

 

[rharr]

There are a few links in thread330-126637. This may give you other ideas. Quite a bit of research has been done on this regarding ships and cold water.

 

[MrMyers]

Check out API-579 Section 3 (i think) where you can conduct a Level 1 or 2 analysis of your design to determine the risk of brittle fracture given various parameters.