K438 is a nickel-base precipitation hardened equiaxial casting superalloy, chemically equivalent to Inconel 738, and is one of the best hot corrosion resistant alloys available. The high chromium level gives strong oxidation and hot corrosion resistance, while niobium and tantalum improve carbide stability. Columnar grain control in the cast body is important for thermal fatigue life, and the alloy is supplied as cast master alloy bar for remelting.
Chinese designation: K438 镍基铸造高温合金母合金
| Element | Min % | Max % |
|---|---|---|
| Cr | 15.7 | 16.3 |
| Co | 8 | 9 |
| Al | 3.2 | 3.7 |
| Ti | 3 | 3.5 |
| W | 2.4 | 2.8 |
| Mo | 1.5 | 2 |
| Ta | 1.5 | 2 |
| Nb | 0.6 | 1.1 |
| Fe | — | 0.5 |
| Si | — | 0.3 |
| C | 0.1 | 0.2 |
| Mn | — | 0.2 |
| Zr | 0.05 | 0.15 |
| B | 0.005 | 0.015 |
| P | — | 0.015 |
| S | — | 0.015 |
| Ni | balance | — |
Chemical composition per the grade specification. Values are nominal; the mill test report is issued with every order, traceable to the heat number.
| Supply form | Standard / specification |
|---|---|
| Master alloy bar, as-cast, vacuum induction melted | YB/T 5248 / GJB 5512.1 |
| Master alloy ingot, ball ingot and button | GJB 5512.1 |
| Horizontally vacuum cast bar | Customer specification |
| Remelted casting rod for investment casting | Customer specification |
Master alloy is supplied in the as-cast condition. The melt route, vacuum level and remelting route for the buyer's own foundry are agreed on the order and recorded on the report.
K438 (K38, Cast Alloy 738, YB/T 5248, GJB 5512.1) is a master alloys grade. K438 is a nickel-base precipitation hardened equiaxial casting superalloy, chemically equivalent to Inconel 738, and is one of the best hot corrosion resistant alloys available. The high chromium level gives strong oxidation and hot corrosion resistance, while niobium and tantalum improve carbide stability. Columnar grain control in the cast body is important for thermal fatigue life, and the alloy is supplied as cas
ROBAN supplies K438 as master alloy bar, as-cast, vacuum induction melted, master alloy ingot, ball ingot and button, horizontally vacuum cast bar, remelted casting rod for investment casting, cut to the length you need and packed for remelting.
Yes. Every order ships with a mill test report covering the actual heat analysis of the melt, together with the heat number and the melt route. 3.2 documentation is available where the contract requires it.
Master alloy is made to order rather than held in stock. The usual lead time is 20 to 40 working days depending on the grade, the melt route and the quantity. Send us your specification for a firm date.
Yes. State the diameter, the length and the condition you need. Bar is normally supplied as-cast and cut to your length, and ingot is supplied as button or cube to match your melting equipment.
Drawing, grade, dimensions, quantity and delivery date — we price from those.
Request a Quote →Heat analysis report issued with every order at no extra charge.
Quality documentation →Shearing, sawing and machining to the tolerances on your drawing.
Capabilities →Buyers often substitute within a family once service conditions, corrosion behaviour or fabrication method narrow the choice.
