The natural choice
Austenitic steels with designations 1.4301 and 1.4307 are the commonest stainless types and contain 18% chromium and 8% nickel. The difference between the two grades is that in 1.4301, the maximum allowed carbon content is higher than for 1.4307 which can mean that 1.4301 has marginally higher strength. In practice, the difference in carbon between 1.4301 and 1.4307 is often of little significance. However, if welding is to be performed, 1.4307 is the preferred choice since corrosion resistance in the vicinity of the weld could be impaired for 1.4301. Flat formats of 1.4301/1.4307 are standardised in EN 10088-2. This standard covers cold-finished thicknesses up to and including 8 mm.
Grades 1.4301 and 1.4307 show good resistance to corrosion in neutral water both indoors and outdoors. The steels also exhibit immunity from atmospheric corrosion. However, these stainless grades are less suitable if the environment is acidic or contains chlorides. In such instances, higher alloyed grades are needed.
The formability of cold-finished sheets of both 1.4301 and 1.4307 is in most cold-forming operations excellent and often better than cold-rolled carbon steel. Both grades are also characterised by very good weldability and they seldom pose any problems in fabrication of welded structures.