SA 516 Gr.70 could attached directly to SA 516 Gr.60

Hi,

The mentioned steels are basically the same material, with the exception, important, for a difference in 0,05%in the carbon content.

I understand by your question that you want to join two or more pieces together with the different materials. It seems that you'll not experience problems, except for the fact that the 70 grade has a higher tensile strengh and less ductility than the 60 grade, what can be very dangerous depending on your application, stress concentrations, etc.

But, if your doubt is regarding welding the different materials, so you may expect in addition to the previous problems, that the weld metal will have a composition that is somewhat between the two materials, and will vary depending on the filler material used and the relative solubility in each of the parts. It may perfectly be acceptable, if you consider that if you are welding you are aware about the loss of material properties in a weld and all the required post weld treatments in critical applications. Here, the resulting microstructure of the metal may vary (a lot).

In other words: in ordinary applications, I dont see any problem, materials are basically compatible. In pressure vessels, I'd better take some care about the resulting joint.

Dear Bhrescobar,

Sir, i mean Vessel Body(shell) fabricated with SA 516 Gr.60 and i want to attached SA 516 Gr.70 to this material as a platform or piping clip not joint these material together.

Thank you.

No, there are no special precautions to make for welding between these two grades.

However, I would take note if the vessel is a pressure vessel, and follow any applicable codes - such as NDE requirements/design/hydro-testing if attaching to the pressure envelope.

No problem at all.

Better not to attach directly to shell. Use doubler plate with material same as the shell from which to attach your appurtenances.