Technical Data.
Types 302, 304, 304L, and 305 stainless steels are variations of the 18 percent chromium – 8 percent nickel austenitic alloy, the most familiar and most frequently used alloy in the stainless steel family. These alloys may be considered for a wide variety of applications where one or more of the following properties are important:
Resistance to corrosion
Prevention of person contamination
Resistance to oxidation
East of fabrication
Excellent formability
Beauty of appearance
Ease of cleaning
High strength with low weight
Good strength and toughness at cryogenic temperatures
Ready availability of a wide range of person forms
Each alloy represents an excellent combination of corrosion resistance and fabricability. This combination of properties is the reason for the extensive use of these alloys which represent nearly one half of the total U.S. stainless steel personion. Type 304 represents the largest volume followed by Type 304L. Types 302 and 305 are used in smaller quantities. These alloys are covered by a variety of construction or use of equipment manufactured from these alloys for specific conditions. Food and beverage, sanitary, cryogenic, and pressure-containing applications are examples.
Past users of Type 302 are generally now using Type 304 since AOD technology has made lower carbon levels more easily attainable and economical. There are instances, such as in temper rolled products, when Type 302 is preferred over Type 304since the higher carbon permits meeting of yield and tensile strength requirements while maintaining a higher level of ductility (elongation) versus that of the lower carbon Type 304. Type 304L is used for welded products which might be exposed to conditions which could cause intergranular corrosion in service. Type 305 is used for applications requiring a low rate of work hardening during severe cold forming operations such as deep drawing.