Stabilized Austenitic

321 Stainless Steel CNC Machining

Titanium-stabilized austenitic stainless steel for high-temperature service. Resists intergranular corrosion and maintains strength up to 900°C.

View Properties

Specifications

Designation:UNS S32100 / AISI 321
Type:Stabilized Austenitic
Stabilizer:Titanium (Ti)
Service Temp:Up to 900°C continuous
Australian Std:AS 2837 Grade 321

Why Choose 321 Stainless?

High Temperature

Maintains strength and resists oxidation up to 900°C continuous service. Superior to 304 for elevated temperature applications.

Intergranular Corrosion Resistance

Titanium stabilization prevents chromium carbide precipitation. Resists sensitization after welding or high-temperature exposure.

Excellent Weldability

Welds without risk of intergranular corrosion in heat-affected zones. No post-weld heat treatment required for corrosion resistance.

Thermal Cycling

Excellent resistance to repeated heating and cooling cycles. Ideal for exhaust systems and expansion joints.

Technical Properties

Chemical Composition (%)

Chromium (Cr)17.0 - 19.0
Nickel (Ni)9.0 - 12.0
Titanium (Ti)5×C min, 0.70 max
Carbon (C)≤ 0.08
Manganese (Mn)≤ 2.0
Key: Titanium content must be at least 5× carbon content to effectively stabilize and prevent carbide precipitation.

Mechanical Properties (20°C)

Tensile Strength515-655 MPa
Yield Strength205-310 MPa
Elongation40-50%
Hardness≤ 217 HB
Max Service Temp900°C continuous

Applications

Automotive Exhaust

  • • Exhaust manifolds
  • • Catalytic converters
  • • Muffler assemblies
  • • Exhaust piping

Aerospace

  • • Aircraft exhaust systems
  • • Jet engine components
  • • Afterburner parts
  • • Expansion joints

Industrial

  • • Heat exchangers
  • • Boiler tubes
  • • Furnace parts
  • • High-temp piping

Chemical Processing

  • • Reactor vessels
  • • Process piping
  • • Storage tanks (heated)
  • • Column internals

Power Generation

  • • Steam generators
  • • Superheater tubes
  • • Turbine components
  • • Thermal expansion joints

Oil & Gas

  • • Refinery equipment
  • • Cracking furnaces
  • • High-temp valves
  • • Flare systems

CNC Machining 321 Stainless

Machining Characteristics

Similar to 304 stainless but slightly more difficult due to titanium content. Work hardens readily - requires sharp tools and continuous feeds.

Machining Parameters

Turning (Carbide)70-110 m/min
Milling (Carbide)60-100 m/min
Drilling18-35 m/min

Best Practices

  • ✓ Carbide tools recommended for production
  • ✓ High-pressure coolant essential
  • ✓ Avoid tool dwell (rapid work hardening)
  • ✓ Positive rake angles reduce cutting forces
  • ✓ Similar to 304 but 10-15% slower speeds

Expert 321 Stainless Steel Machining

High-temperature stainless steel machining for exhaust, aerospace, and industrial applications.