321/321H

These titanium bearing stainless steels are stabilized against carbide precipitation and designed for operation within the damaging temperature range where carbide precipitation develops. In this type of steel, the carbon combines preferentially with titanium to form a harmless titanium carbide, leaving the chromium in solution to maintain full corrosion resistance.

Type 321 is basic type 304 modified by adding titanium in an amount at least 5 times the carbon plus nitrogen contents.

• Immune to intergranular corrosion when heated within the carbide precipitation range.
• Titanium addition eliminates the formation of chromium carbides at the grain boundaries by typing up the carbon and nitrogen as titanium carbides or nitrides.
• Better high temperature properties than 304 or 304L. Generally used for parts which are intermittently heated up to 1500 ̊ F. For continuous service the alloy is good to 1650 ̊ F.
• May be susceptible to chloride stress cracking.
• Excellent weldability in field.
• Type 321H has high carbon (.04-.10) for
  better high temperature creep properties.

• High temperature chemical process heat exchanger tubes
• Refineries
• High temperature steam service

KSI can be converted to MPA (Megapascals) by multiplying by 6.895.