Welding of austenitic(316Ti) to martensitic(422) 1

You have several options. Before providing any recommendation you need to specify your application - service temperature and environment.

This welding is to be used in high temperature services. The material is connected in the thermal block of steam turbine.

Ok. I would recommend Inconel 82 filler metal, SFA 5.14 ERNiCr-3 for this dissimilar metal weld. You will need to apply a local preheat of 450 deg F for the AISI 422 martensitic stainless steel, and probably PWHT.

What type of weld joint are you considering - butt weld or socket weld?

Thanks metengr. Actually, I have similar proposal to our company. The reason i'm asking a specialist like you is to make sure i'm in the right track...