INCONEL 713C K418 Round Bar Cast Nickel Superalloy for Gas Turbine Blades

INCONEL 713C / K418 Round Bar for Gas Turbine Blades and Nozzle Vanes

This bar stock is dual designated: INCONEL 713C (UNS N07713, AMS 5391) for export drawings and K418 (GB/T 14992) for Chinese drawings, both describing the same vacuum melted, gamma-prime strengthened nickel-chromium casting alloy used across gas turbine hot sections. It is supplied in 80 mm diameter for producing blades, nozzle guide vanes, vane segments and small integral wheels on machines where a cast structure is specified and a dedicated casting pattern is not justified.

Why blade shops work from 713C / K418 bar

• Creep strength where it matters: gamma-prime volume fraction is high enough to hold load at 760–980 °C, the band where first and second stage blade roots and platforms operate.
• Thermal fatigue tolerance: repeated start-stop cycling in combustion gas produces steep thermal gradients; this alloy resists crack initiation at fillets and cooling slot edges better than solid-solution grades.
• Hot corrosion margin: the 12–14% chromium level tolerates sulphur and vanadium carryover from lower grade fuels, which matters for industrial and marine turbines.
• Proven service history: 713C has decades of blade and vane service, and K418 is its long established domestic counterpart, so approval documentation is straightforward for both export and domestic projects.
• Small lot flexibility: prototype and spare blade batches can be cut from bar without tooling investment, and worn parts can be weld repaired and re-machined.

Elevated temperature strength for blade design

Figures are typical for cast and aged material and are given for design guidance only; actual values are certified per heat on the mill test report.

Position among common blade casting alloys

Where a drawing specifies K418B, the higher boron variant used to improve castability in thin sections, we quote a dedicated heat with adjusted boron and confirm chemistry before shipment.

Bar data and test package

• Chemical analysis by heat, Ni balance with Cr 11.5–14%, Al 5.5–6.5%, Mo 3.8–5.2%, Nb 1.8–2.8%, Ti 0.5–1.0%, C 0.08–0.20%
• Tensile and yield testing at room temperature and at 850 °C on request
• Stress rupture testing to 1000 h at agreed stress and temperature
• Fluorescent penetrant inspection and radiographic examination to ASTM E192 or E446 for finished parts
• Hot isostatic pressing available as an add-on for porosity sensitive blade sections
• Documentation: EN 10204 type 3.1 certificate stating both INCONEL 713C and K418 designations

Machining notes for blade features

Root forms, fir tree serrations and cooling holes are best produced with sharp carbide or ceramic tooling under rigid conditions and generous coolant, avoiding dwell that work-hardens the surface. Where dimensional stability matters, rough machine, stress relieve, then finish. Welded repairs to blade tips or platform edges should be heat treated and re-inspected before return to service.

Ordering

Send the blade or vane drawing, the required bar diameter, cut length and quantity together with the applicable specification (AMS 5391, GB/T 14992 or your own internal standard) and we will confirm heat availability, test scope and lead time. Stocked diameters normally leave the works within about a week; HIP and extended testing add to the schedule.

Contact our engineering sales team with your blade specification for a stock and test cost quotation.