The excellent formability of Alloy 28 permits cold bending to very small bending radii. Annealing is not normally necessary after cold bending.
For operating temperatures over 400°C (800°F), heat treatment should be carried out after bending to ensure good ductility after prolonged service times.
Alloy 28 is expanded into tube sheets in the same way as standard austenitic stainless steels.
The machining of Alloy 28, as with other stainless steels, requires an adjustment of tooling data and machining method, in order to achieve satisfactory results. Compared to Sanmac 316/316L, the cutting speed must be reduced by approximately 50-55% when turning Alloy 28 with coated, cemented carbide tools. Much the same applies to other operations. Feeds should only be reduced slightly and with care.
Detailed recommendations for the choice of tools and cutting data are provided in the brochure S-02909-ENG. Data should be selected as for steel grade Sanmac 316/316L, while taking into account the provisions above.