INCONEL™ 738: FORGING FACTS & CHARACTERISTICS

Inconel™ 738 offers a combination of outstanding high-heat creep-rupture strength and corrosion resistance better than many high-strength superalloys with lower chromium content. Inconel 738 is a nickel-based alloy, vacuum-cast and precipitation-hardened, offering exceptional mechanical properties to 1800°F (982°C). IN-738 holds up to the hot corrosive environments found in the turbine industry.

CHEMICAL COMPOSITION OF INCONEL™738

• Carbon 0.15-0.20
• Cobalt 8.00-9.00
• Chromium 15.70-16.30
• Molybdenum 1.50-2.00
• Tungsten 2.40-2.80
• Tantalum 1.50-2.00
• Columbium 0.60-1.10
• Aluminum 3.20-3.70
• Titanium 3.20-3.70
• Aluminum and titanium 6.50-7.20
• Boron 0.005-0.015
• Zirconium 0.05-0.15
• Iron 0.50 max
• Manganese 0.20 max
• Silicon 0.30 max
• Sulfur 0.015 max
• Nickel remainder

HEAT TREATMENT OF INCONEL™738

• 2050°F (1121°C) for 2 hours
• Air cool
• 1550°F (843°C) for 24 hours
• Air cool

APPLICATIONS OF INCONEL™ 738

• Inconel 738 is most commonly used for gas turbine blades and vanes for industrial use.

MACHINABILITY OF INCONEL™ 738

• Sturdy and short drills, reamers, taps and end mills
• Positive feeds with no tool dwelling
• High-speed tools in turning operations
• Carbide tools for tapping, reaming and drilling
• Lubricate continuously
  • Chemical emulsions for turning
  • Chlorinated oil for tapping, reaming, drilling and milling
• 6000 rpm wheel speed for surface grinding, using highly sulfurized oil
• Normal finish grinding techniques

CORROSION RESISTANCE OF INCONEL™ 738

• Exceeds strong superalloys
• Resists oxidation to 2000°F (1093°C)
• Improved sulfidation resistance up to 1800°F (982°C)
• Demonstrated resistance atmospheres with hydrogen sulfide and sulfur dioxide to 1800°F (982°C)