ThePipingMart Blog Welding Electrodes HAYNES® M400 Welding Wire – Composition, Properties, and Uses

HAYNES® M400 Welding Wire – Composition, Properties, and Uses


In many industries, the need for high-temperature materials that can withstand challenging environments is paramount. That is where the innovative HAYNES® M400 comes in – a nickel-molybdenum-chromium alloy designed to resist extreme conditions. This high-performance alloy boasts a unique combination of strength, durability, and ductility, making it an excellent candidate for applications where traditional materials would fail. This blog will explore what HAYNES® M400 is, its composition, mechanical and physical properties, corrosion resistance, heat treatment, and its uses.

What is HAYNES® M400 Welding Wire?

HAYNES® M400 is a nickel-based superalloy with superior strength and creep resistance at elevated temperatures. Its excellent oxidation, carburization and sulfidation properties, and fatigue and stress corrosion cracking resistance are used in many applications such as jet engine parts, gas turbine components, petrochemical plant piping systems and industrial heating elements. Its low thermal expansion can be manufactured to close tolerances for reliable performance even when subject to extreme temperatures.

HAYNES® M400 Coated Wire Composition

HAYNES® M400 welding electrode consists of 39% nickel, 19% molybdenum, and 15% chromium, amongst other elements such as iron, cobalt, and tungsten, giving it a balanced chemical composition. The combination of nickel and molybdenum provides the alloy with outstanding resistance to corrosion and oxidation, while chromium enhances its mechanical properties, making it more durable and resistant to wear.

Elements Content (%)
Nickel, Ni 30 – 45
Chromium, Cr 12 – 32
Cobalt, Co  5
Molybdenum, Mo  5
Columbium + Tantalum (Cb + Ta)  4
Silicon, Si  3
Manganese, Mn  2
Carbon, C  0.20

HAYNES® M400 Welding Wire Mechanical Properties

The high mechanical strength and toughness of HAYNES® M400 electrode make it withstand high-stress and high-temperature environments. Its tensile strength is approximately 150 ksi (1 ksi = 1000 pounds per square inch), with an elongation of around 20%. The high flexibility and toughness make HAYNES® M400 an excellent choice for components that must withstand dynamic loads.

Properties Metric Imperial
Tensile strength  450 MPa  65300 psi
Yield strength  240 MPa  34800 psi
Elongation at break  25%  25%

HAYNES® M400 Coated Wire Physical Properties

The physical properties of HAYNES® M400 filler metal make it a desirable material for extreme environments. Its melting temperature ranges between 2400-2500°F, and its density is around 0.307 lb/in³. The alloy has a thermal conductivity of approximately 60 Btu/hr·ft·°F, and its coefficient of thermal expansion ranges from 7.1 to 7.6 micro inches per linear inch per °F.

HAYNES® M400 Welding Wire Trade Names

Class UNS Haynes
QQ-N-281 N04400 HAYNES® M400

HAYNES® M400 Coated Wire Uses

HAYNES® M400 filler wire is a popular choice in aerospace, power generation, chemical processing, and various other industries. The alloy’s resistance to high-temperature environments makes it ideal for manufacturing combustion chambers, gas turbine components, and furnace muffles. Additionally, its excellent corrosion, erosion, and wear resistance makes it desirable for producing pumps, valves, and other components subjected to harsh environments.

HAYNES® M400 Welding Wire Corrosion Resistance

HAYNES® M400 welding metal possesses exceptional resistance to both oxidation and corrosion. It can resist hot and sulfurous environments, making it useful when traditional materials fail. The presence of molybdenum in the composition of HAYNES® M400 enhances its corrosion resistance, making it ideal for components in harsh chemical environments.

HAYNES® M400 Coated Wire Heat Treatment

HAYNES® M400 welding wire is solution-treated at around 2150°F and cooled rapidly before its final annealing process to ensure homogeneity. The annealing process allows HAYNES® M400 to develop its full strength, toughness, and flexibility while improving its machinability and weldability.


In conclusion, HAYNES® M400 is a robust alloy with unique properties, making it an excellent candidate for harsh, high-temperature environments. Its mechanical and physical properties, corrosion resistance, and heat treatment make it a reliable choice for manufacturing components in aerospace, power generation, and various other industries. Considering its valuable properties, HAYNES® M400 is an alloy worth exploring by engineers and manufacturers looking for materials capable of withstanding challenging environments.

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