Workability

N08031 has cold and hot workability similar to that of standard austenitic stainless steels. However, the high strength of this material must be considered in both cold working and hot working.

Weldability

Welding can be performed by TIG, MIG, and shield metal arc welding in much the same manner as with standard austenitic stainless steels. Alloy 276 welding consumable should be used.

Machinability

As a feature of high Ni stainless steels, machining of N08031 is difficult in comparison with standard austenitic stainless steels, but it is easier than with nickelbased alloys. A ultrahard tool should be used in machining if at all possible. It is also advisable to use a slower feed rate and deeper cutting depth.

Heat Treatment

Because N08031 is an austenitic stainless steel, heat treatment is equivalent to that with the standard austenitic stainless steels. The following heat treatment conditions are normally used:

• Solution heat treatment: 1150~1180℃; Water cooling

Pickling

A mixture of nitric acid and hydrofluoric acid is used in pickling. However, due to the high corrosion resistance of N08031, scale is somewhat difficult to remove in comparison with Type 304. Therefore, the material should be immersed in an alkaline solution before pickling, or if possible, shot blasting is extremely effective.

Applications

Chemical plants, flue gas desulfurization equipment, papermaking plants, heat exchangers using seawater, offshore structures.