Chromium Nickel Austenitic Steels

Chromium Nickel Austenitic Steels (Not capable of heat treatment).—SAE 30201:
This steel is an austenitic chromium–nickel–manganese stainless steel usually required
in flat products. In the annealed condition, it exhibits higher strength values than the corresponding
chromium–nickel stainless steel (SAE 30301). It is nonmagnetic in the annealed
condition, but may be magnetic when cold-worked. SAE 30201 is used to obtain high
strength by work-hardening and is well suited for corrosion-resistant structural members
requiring high strength with low weight. It has excellent resistance to a wide variety of corrosive
media, showing behavior comparable to stainless grade SAE 30301. It has high ductility
and excellent forming properties. Owing to this steel’s work-hardening rate and yield
strength, tools for forming must be designed to allow for a higher springback or recovery
rate. It is used for automotive trim, automotive wheel covers, railroad passenger car bodies
and structural members, and truck trailer bodies.
SAE 30202: Like its corresponding chromium–nickel stainless steel SAE 30302, this is a
general-purpose stainless steel. It has excellent corrosion resistance and deep drawing
qualities. It is nonhardenable by thermal treatments, but may be cold worked to high tensile
strengths. In the annealed condition, it is nonmagnetic but slightly magnetic when coldworked.
Applications for this stainless steel are hub cap, railcar and truck trailer bodies,
and spring wire.
SAE 30301: Capable of attaining high tensile strength and ductility by moderate or
severe cold working. It is used largely in the cold-rolled or cold-drawn condition in the
form of sheet, strip, and wire. Its corrosion resistance is good but not equal to SAE 30302.
SAE 30302: The most widely used of the general-purpose austenitic chromium–nickel
stainless steels. It is used for deep drawing largely in the annealed condition. It can be
worked to high tensile strengths but with slightly lower ductility than SAE 30301.
SAE 30303F: A free-machining steel recommended for the manufacture of parts produced
on automatic screw machines. Caution must be used in forging this steel.
SAE 30304: Similar to SAE 30302 but somewhat superior in corrosion resistance and
having superior welding properties for certain types of equipment.
SAE 30305: Similar to SAE 30304 but capable of lower hardness. Has greater ductility
with slower work-hardening tendency.
SAE 30309: A steel with high heat-resisting qualities which is resistant to oxidation at
temperatures up to about 1800 degrees F.
SAE 30310: This teel has the highest heat-resisting properties of any of the chromium
nickel steels listed here and will resist oxidation at temperatures up to about 1900 degrees
F.
SAE 30316: Recommended for use in parts where unusual resistance to chemical or salt
water corrosion is necessary. It has superior creep strength at elevated temperatures.
NUMBERING SYSTEMS 429
SAE 30317: Similar to SAE 30316 but has the highest corrosion resistance of all these
alloys in many environments.
SAE 30321: Recommended for use in the manufacture of welded structures where heat
treatment after welding is not feasible. It is also recommended for use where temperatures
up to 1600 degrees F are encountered in service.
SAE 30325: Used for such parts as heat control shafts.
SAE 30347: This steel is similar to SAE 30321. This niobium alloy is sometimes preferred
to titanium because niobium is less likely to be lost in welding operations.