Hello to everybody,
I am new in this forum, so please do not hurt me very hard . And sorry for my English, it is not my native language.
At my workshop we weld pipes 0,5 mm thickness with automatic longitudinal TIG welding machine without filler material (autogenous method). Regularly we use 1.4301 (304) and 1.4404 (3016L) austenitic stainless steels. At this moment for some products I am trying to start use 1.4016 (430) feritic stainless steel.
After the welding I have to expand the pipes ends (male and female).
1.4016 has 20 percent elongation before fracture. 1.4301 and 1.4404 - about 40 percent.
So during the female expansion, the pipe fracture at welding seam. It happens only on the welding seam, so I think main material elongation is enough for this type of expansion. But during the welding my heat affected zone become much more brittle.
The tried welding amperage was from 160A to 200A. It is the same situation. We use 1,6 mm tungsten electrode and Ar95H5 mixture of shielding gas.
Does somebody have experience or any idea how to eliminate this problem and make the welding seam more plasticity?
I am new in this forum, so please do not hurt me very hard . And sorry for my English, it is not my native language.
At my workshop we weld pipes 0,5 mm thickness with automatic longitudinal TIG welding machine without filler material (autogenous method). Regularly we use 1.4301 (304) and 1.4404 (3016L) austenitic stainless steels. At this moment for some products I am trying to start use 1.4016 (430) feritic stainless steel.
After the welding I have to expand the pipes ends (male and female).
1.4016 has 20 percent elongation before fracture. 1.4301 and 1.4404 - about 40 percent.
So during the female expansion, the pipe fracture at welding seam. It happens only on the welding seam, so I think main material elongation is enough for this type of expansion. But during the welding my heat affected zone become much more brittle.
The tried welding amperage was from 160A to 200A. It is the same situation. We use 1,6 mm tungsten electrode and Ar95H5 mixture of shielding gas.
Does somebody have experience or any idea how to eliminate this problem and make the welding seam more plasticity?