The first step in selecting materials is to clarify the usage environment. At present, the three most widely circulated brands in the market each have their own focus:

304 stainless steel: preferred for versatility
304 (UNS S30400) is the most commonly used choice among austenitic stainless steels. It has excellent comprehensive mechanical properties and corrosion resistance, and is usually non-magnetic in the annealed state. Its typical tensile strength is between 515-680 MPa, with an elongation rate of over 45%, and good formability during processing. For most indoor structural components, food processing equipment (such as beer brewing, milk processing), and kitchen utensils that do not involve strong corrosive media, 304 is the most cost-effective solution. It should be noted that 304 is prone to pitting corrosion in chloride environments (such as coastal or de icing salt contact areas) and is not recommended for high salt spray exposure scenarios.

316L stainless steel: corrosion resistance upgrade plan
When the application scenario involves chemical, marine, or high salt environments, 316L (UNS S31603) is a more reliable choice. Compared with 304, 316L has added 2-3% molybdenum (Mo) element, which significantly improves its ability to resist pitting and crevice corrosion, especially in media containing chloride ions, showing much better performance than 304. In addition, the low carbon content (≤ 0.03%) of 316L allows it to avoid intergranular carbide precipitation (sensitization) after welding thick sections without the need for post weld annealing treatment. Therefore, it is widely used in chemical pipeline fittings, heat exchangers, pump valve components, and coastal facilities. Its yield strength (Rp0.2) is typically above 205 MPa, balancing strength and corrosion resistance requirements.

430 Stainless Steel: Cost Sensitive Decorative Applications
430 (UNS S43000) belongs to ferritic stainless steel and does not contain nickel or only contains trace amounts of nickel, so its cost is significantly lower than that of the 300 series. It has good resistance to nitric acid corrosion and oxidation (up to 870 ° C for intermittent use), and a low coefficient of thermal expansion. But the ductility of 430 is not as good as 304, and its welding performance is relatively limited. It is most suitable for cost sensitive and low corrosion requirements scenarios, such as home appliance panels (washing machine, refrigerator door panels), decorative lines, low-end sinks, and car trim. It should be noted that 430 has poor toughness at low temperatures and may become brittle in the 400-600 ° C range for a long time. When selecting, it is necessary to avoid high-temperature and pressure bearing conditions.