UNS N14052 Forgings: Alloy 52 / Nilo 52 Forged Rings, Bars and Flanges

What UNS N14052 is

UNS N14052 belongs to the controlled-expansion family of nickel-iron alloys. Its nominal 50.5 % nickel content gives a thermal expansion curve that stays close to linear from room temperature up to about 565 °C (1050 °F). Over that range the expansion closely matches soft lead and soda-lime glasses, so a seal made between the two will hold vacuum through repeated thermal cycling without cracking.

The alloy is also sold as Alloy 52, Nilo 52, Invar 52, Pernifer 50, HyRa 49 and Glass Sealing 52. It carries Werkstoff number 2.4478 and AWS classification 093, and is covered by ASTM F30 and by AMS-I-23011A (which superseded MIL-I-23011C), Class 2.

Chemical composition of UNS N14052

The chemical composition of UNS N14052 conforms to ASTM F30. Jiangyin Jiangnan Metal melts the alloy by EAF + VOD followed by ESR remelting, which lowers residual sulphur and improves ingot soundness before forging.

Cobalt may be present as an incidental element. The composition of each delivery is reported on the mill test certificate; confirm against your drawing before design release.

Mechanical properties of UNS N14052

Tensile strength of UNS N14052 depends on temper. The tempers below follow the ASTM F30 cold-worked designations. Forged rings, bars and discs are normally supplied in the annealed temper, because the cold work that produces the harder tempers shifts the coefficient of thermal expansion away from the glass-sealing range.

The alloy holds useful strength and hardness down to cryogenic temperatures. Values are typical rather than guaranteed minima; state the required property range on the enquiry and it will be written into the order.

Physical properties of UNS N14052

UNS N14052 is bought for its controlled thermal expansion. Expansion is nominally constant up to roughly 565 °C, above which the curve inflects.

Physical property values are nominal and taken from published mill data for the grade. For design calculations, work from the certified values on the mill test certificate supplied with your forgings.

UNS N14052 equivalent grades and designations

UNS N14052 is sold under several trade names. All of the following refer to the same nominal 50.5 % nickel-iron controlled-expansion alloy.

How UNS N14052 compares with neighbouring controlled-expansion alloys

Nickel content controls the expansion coefficient, which in turn decides which glass the alloy will seal to. Moving one grade up or down the range changes the sealing target rather than the general behaviour.

UNS N14052 forged products we manufacture

Jiangyin Jiangnan Metal is an open-die forging factory, so UNS N14052 parts are forged to a customer drawing rather than pulled from a catalogue. Rings are produced on a radial ring-rolling mill as seamless rolled rings; solid shapes are cogged, upset and punched on open-die presses.

Related open-die forms are described on our forged ring and forged bushing pages.

Manufacturing route, testing and certification

Melting and forging

UNS N14052 is melted by electric arc furnace with vacuum oxygen decarburisation, then electroslag remelted (EAF + VOD-ESR). ESR ingots are homogenised before forging to reduce segregation. Forging is followed by a full anneal in the 850 to 1000 °C range under protective atmosphere, which restores the controlled expansion characteristic after hot work.

Non-destructive testing

Ultrasonic testing of UNS N14052 forgings is performed to the standard nominated on the order. Jiangyin Jiangnan Metal routinely tests to:

• EN 10228-3, ultrasonic testing of ferritic and martensitic steel forgings
• SEP 1921, ultrasonic testing of steel bars and forgings
• ASTM A388, ultrasonic examination of heavy steel forgings

Dye-penetrant testing, magnetic particle testing, hardness survey and dimensional inspection are available on request.

Certification

Material certificates for UNS N14052 forgings are issued to EN 10204 3.1, or to EN 10204 3.2 with third-party witness and endorsement by an inspection body such as TÜV, SGS, BV or Lloyd's Register. Certificates report heat number, chemical analysis, mechanical test results, heat-treatment record and NDT results, and are traceable to the ingot.

Applications of UNS N14052 forgings

UNS N14052 forgings are used in electronic, lighting, vacuum and precision-instrument assemblies. Typical applications are listed below.

• Glass-to-metal sealsElectronic tubes, hermetic feedthroughs and sealed devices using soft lead or soda-lime glasses.
• Lighting and vacuum devicesAutomotive and industrial lamp components, electric lamp bulb parts, vacuum device housings.
• Reed switches and relaysMagnetic reed switch bodies and sealed contact assemblies requiring linear expansion.
• Microwave and RF hardwareRadar and microwave cavity resonators, echo boxes and filters for mobile telephony.
• Precision instrumentsDimensionally stable instrument frames, optical device mounts, metrology fixtures.
• Thermostatic componentsBimetal thermostats, thermostatic bi-metal strip backing, temperature regulators.
• Electrical apparatusSmall transformers, reactors, pole shoes, earth-leakage breaker parts, circuit breakers.
• Valve and sealing partsForged valve stems, seat rings, bodies and blocks for ball, gate, globe, check and plug valves.

Forged forms used in these applications include seamless rolled rings, flanges, shafts, spindles, discs, sleeves, bushings, tube sheets and machined-from-solid blanks.

UNS N14052 forgings, frequently asked questions

About the manufacturer