Hastelloy X

Hastelloy X (also known as Hast X and Alloy X) is a nickel-based superalloy known for its remarkable heat, corrosion, and oxidation resistance. Because of its superior high-temperature strength and fabrication abilities, Hast X is the go-to metal for highly combustive applications and components including industrial furnaces and flame holders, chemical processing, and gas turbine engineering. While primarily based in high temperature nickel, Hastelloy X chemical composition also includes high amounts of chromium, molybdenum and iron. Standard specifications include AMS 5536, UNS N06002 and more.

At Rickard Specialty Metals, we have 25+ years of experience supplying Hastelloy X sheet, plate, forgings and more to your custom measurements and shapes. Our forging process includes open die forgings, ring rolling and more. Additionally, we provide Hast X heat treatment. See below for a list of common Alloy X forged shapes, including flat bar and round bar, and additional product forms we offer.

Hastelloy X Additional Information:

Physical Properties

Hardness: Per AMS 5754 hardness is 241HB max in the solution anneal heat treated condition for bars and forgings, and 277 HB max for flash welded rings.
Density: 0.297 lbs per cubic inch.
Modulus of Elasticity: 29.8 MSI.
Coefficient of Expansion: 7.9 x10-6 in/in/F RT-800F. 8.8 x10-6 in/in/F RT-1400F.

Machining

Hastelloy X machining can be performed with conventional methods. Carbide tools are preferred, but high-speed steel cutting tools can also be used. Machinability is similar to that of austenitic stainless steels. The alloys is tough and, therefore, requires rigid fixturing, low cutting speeds and ample cutting fluids, either water-base or sulfochlorinated oil. Additionally, finish grinding is recommended when very close tolerances are required.

Welding

Similar to other nickel alloys we supply, such as Inco 625 & Inco 718, Hastelloy X has excellent welding ability, particularly in conjunction with gas-tungsten-arc (GTA), plasma-arc, and electron-beam welding. Generally, parent metal weld filler is used with welding carried out on solution heat treated material. Often post-weld heat treatment is employed to reduce residual weld shrinkage stresses. Strength and ductility are good in the as-welded condition, but a full post-weld solution heat treatment or lower temperature stress relief (1800F min) is often applied to obtain optimum properties (dimensional stability, fatigue life) in weldments.

Forming

Hastelloy X has very good forming ability when solution heat treated and can be cold formed by most of the common methods including drawing, rolling, bending, spinning, drop hammering, punching and shearing. The solution-treated condition is optimum for cold-forming operations because it provides minimum hardness and maximum ductility. Nevertheless, as a result of Hast X’s toughness and hardenability, relatively high energy levels and frequent intermediate solution treatments are required during severe cold forming operations. When performing simple bending operations on a brake press, Hastelloy X seldom requires lubrication. However, when performing severe forming, heavy-duty lubricants such as metallic soaps, chlorinated or sulfochlorinated oils are required. Additionally, land oil, caster oil or sperm oil lubricants are recommended for intermediate forming. Generally, after final cold working, parts should be solution treated to restore the optimum combination of mechanical properties and corrosion resistance.

Corrosion Resistance

Hastelloy X possesses excellent corrosion and oxidation resistance. It also has good sea water corrosion resistance and thus attractive for marine applications.

Heat Treatment

Hastelloy X wrought products are normally supplied by the mills in the solution heat treated condition, which provides the optimum combination of mechanical properties and corrosion resistance for practically all applications. Hastelloy X solution heat treatment consists of exposure to 2150 F followed by rapid cooling. The hold time at 2150 F varies with the section size of the product, size of load and furnace characteristics. A rule of thumb that provides acceptable results for the Haste X product being treated is to hold for 1 hour per inch of thickness. The cooling rate from 2150 to 1000 F or below should be rapid enough to prevent carbide precipitation, which decreases corrosion resistance and toughness for Hastelloy X sheet products. Rapid air cooling is adequate for this process, however, oil or water quenching is frequently necessary for heavier sections. If surface oxidation can be tolerated, the Hastelloy X solution treatment can be carried out in air or in the normal mixture of air and combustion products in gas-fired furnaces. Alternatively, oxidation can be minimized by the use of an exothermic furnace atmosphere or it can be almost entirely prevented by dry hydrogen, dry argon or vacuum atmospheres.

Forging

Hastelloy x Forging should be carried out in the temperature range of 2150 to 1750 F with relatively moderate reductions per pass. Additionally, frequent reheating is required. Hast X hot upsetting is feasible when the length to be upset is no more than three times the diameter. Impact extrusion should be carried out near the upper end of the forging temperature range.

Nominal Thickness (in)	Tensile Strength KSI	Yield Strength at 0.2% KSI	Elongation in 2 Inches or 4D
Up to 0.010, excl	45	—
0.010 to 0.020, excl	105	45	29
0.020 to 0.1874, incl	105	45	35
Over 0.1874 to 2.000, incl	100	40	35
Over 2.000	95	40	35