It is used extensively in consumer products and appliances, and equipment for domestic and commercial kitchens, hospitals, transportation and waste water treatment. S30400 is also available in virtually all product forms and finishes. It is again stressed that minor differences between apparently similar environments, e.g. presence of chloride, can significantly alter the corrosion rates. Local corrosion, such as the related mechanisms of pitting and crevice corrosion, is largely controlled by the presence of chlorides in the environment and exacerbated by elevated temperature and surface deposits. Keeping a stainless steel surface clean is an important way of minimising corrosion.
Surface roughness can also help in initiating corrosion, so the smoother the surface, the better.
The ferritic and duplex grades are highly resistant, though not immune, and should be selected if SCC is a possibility. Often, a grade is selected for the required corrosion resistance, and the mechanical and physical properties of the grade are only considered in the subsequent design process. However, these properties are fundamental and should be considered as early as possible in the selection process. For example, while a duplex grade like S31803 is highly corrosion resistant, it may also be more cost-effective in the long term for a given application due to its high strength. Selection for Fabricability Fabricability should be considered early in the grade selection process - it greatly influences the cost of the product.