Alloy N-155

Multimet N155 is a nickel-chromium-cobalt alloy with molybdenum, tungsten and columbium additions. As such it has good high-temperature properties and can be used to 1500ºF where high stresses are involved and up to 2000ºF where stresses are moderate. It has excellent oxidation resistance, good ductility, and can be readily fabricated and machined. N155 Nickel Alloy is used in various aircraft applications, including tail pipes and tail cones, afterburners, exhaust manifolds, turbine blades and buckets, combustion chambers, and bolts.

Alloy N-155 Forging of ingots should be done at 2200ºF following thorough soaking. Forging of semi-finished products can be started at 2150ºF and can be carried on down to around 1900ºF prior to the necessity for reheating. UNS R30155 solution treatment can be carried out at 2100-2280ºF for one hour followed by rapid cooling, with the higher temperature providing the highest rupture strength and the lower temperature providing the best ductility. Its aging can be done at 1400-1500ºF for 16 hours followed by air cooling. Alloy N-155 Sheet has low speeds and positive feeds together with a rigid set up are the order of the day for machining it. In the fully heat-treated condition machinability will be better. Multimet N155 Plate can be is easily welded by Gas Metal Arc Welding (GMAW), Gas Tungsten Arc Welding (GTAW), Shielded Metal Arc Welding (SMAW), and resistance welding techniques. Submerged Arc Welding (SAW) is not suggested as this process is characterized by high heat input to the base metal and slow cooling of the weld. This element can increase weld restraint and encourage cracking. UNS R30155 Rod/ Tube/ Pipe has high temperature properties which are intrinsic and do not depend upon age hardening. It can be forged, machined, and cold-formed by standard methods.