How to correctly specify the right PWHT

[Everynameistaken]

Hi,
We are doing the structural design along a very large Clevis that needs to attach a large tension load to a concrete structure.
For construcatibitly the clevis needs to be bolted onto the face of the concrete. Anchoring to the concrete is not an issue using quite large dywidag anchor bars.

The potential issue we have is the clevis is made up of two 2” thick plates welded into a T. This calls for a pretty big weld, either partial penetration with two fillet welds on each side or a complete pet relation weld.

Due to all the heat in the welding we are concerned with the effects of this on the clevis as 100% of the load is taken by this weld.

Do you think we should be PWHT this weld and if so how do we specify it? Should it be annealed or normalized? Or is it enough to say “ ensure weldment is fully stress relieved using PWHT in accordance with fabricators welding engineers approved welding process and procedures”

A little bit outside our area of expertise, especially when the loads are so high and not your typical small to medium structural weld!


Cheers

 

[weldstan]

More info needed re plate material, weld design (full penetration or fillet), welding process.

 

[Everynameistaken]

The plate grade is 350W, i think this is 50W is the US?

We are designing the structural capacity of this weld now, and we are leaning towards a partial penetration groove weld on ether side of the plate plus a fillet weld on each side.

The process is typically designed by the contractors welding engineer but I believe it will be E70XX

 

[weldstan]

While you should certainly preheat to 100 C, whether you should PWHY will greatly depend on loading conditions during service. If loads are close (70% or greater) to the yield strength or somewhat impact loaded, do consider PWHT at 620 C for at least 1.5 hrs.

 

[dhengr]

Everynameistaken:
Are you designing a pin pl. welded to a base pl. or are you designing a clevis, which usually implies two pin pls., side by side, and then welded to the base pl? What’s a “large tension load?” What makes you think you need PWHT on this weldment? What problem or problems are you trying to fix with the PWHT? You do realize that there are thousands of weldments like this made every day which do not get any, or need any PWHT. Of course, it is important to design the welds properly and to use the correct welding methods, processes and procedures. Good weld design involves good smooth load paths for the loads/stresses, good clean detailing, no stress raisers or weld conditions which might lead to defects and the like. Most welds do not need any post weld treatments to perform as intended. And, various levels of inspection are important to the whole process. You may need the 2” thick pl. at, and immediately around the pin hole, but it is doubtful that the whole pl. needs to be that thick. And, it is unlikely that you need a full pen. weld btwn. the two pls. Over welding can be as much a detriment to a good weld joint as insufficient weld is.