Tube and pipe manufacturer OSTP has completed three trials of Outokumpu's new austenitic stainless grade Supra
316plus (EN 1.4420, ASTM UNS S31655), giving the product high marks for performance in each case.
OSTP, which produces equipment for the chemical, pulp and paper, and oil and gas industries, carried out the tests at its facility in Jakobstad, Finland. It evaluated the grade on its 219 mm, 42.4 mm and 60 mm tube lines, rounding off the final trial in late February.
“Everything worked out in the three different welding lines. We produced both heat-treated and non-heat-treated tubes and all of those tests went well. We found the results very successful,” says
Bengt Slotte, OSTP's Product Development & Application Engineer.
Testing focused primarily on the material's formability as well as its welding parameters – the specifications and techniques needed for welding in specific tube lines. Slotte noted that there were almost no differences in performance from the other austenitic grades the company currently uses.
“Compared to 4404, which is the closest grade to this one, it performed very similarly. We actually couldn't see any difference in the forming. Regarding the welding, we basically had the same parameters as with the 4404 grade. There were only very minor adjustments that we had to do from the 4404,” he says.
According to Slotte, the pickling process, tested for the 2B finish, went smoothly with the Supra 316plus, and the end product passed the entire standard testing that OSTP carries out on its production.
Supra 316plus has higher mechanical strength and better corrosion resistance than 316L/4404, which can be key advantages from the customer's point of view.
“The fact that manufacturing parameters and performance, as the tests have shown, are nearly identical to a currently used grade means it will be easy for OSTP to offer Supra 316plus as an option,” Slotte says.
“When it starts to become more recognized in the market and designers discover it, there's no problem for us to produce these tubes. We can take it into production whenever needed.”