ThePipingMart Blog Welding Electrodes HAYNES® M418 RTW Welding Wire – Composition, Properties, and Uses

HAYNES® M418 RTW Welding Wire – Composition, Properties, and Uses


Are you in the market for high-performance materials for high-temperature applications? Look no further than HAYNES® M418 RTW. This nickel-based alloy offers superior properties when it comes to mechanical strength, corrosion resistance, and heat treatment. This blog post will explore the composition and properties of HAYNES® M418 RTW and its various applications.

What is HAYNES® M418 RTW?

HAYNES® M418 RTW is an alloy of copper, nickel, chromium and zinc designed for high-temperature (1300°F/704°C) and corrosive environments. Its corrosion resistance and metallurgical stability make it ideal for applications requiring strength and oxidation resistance, such as steam generator tubing in power plants, boiler tubing, heat exchanger tubes and piping systems. The alloy also provides excellent thermal cycling properties, which allows it to be used in automotive exhaust systems.

HAYNES® M418 RTW Welding Wire Composition

HAYNES® M418 RTW metal is a nickel-based alloy that contains 55% nickel, 20% chromium, 18% iron, 5% molybdenum, and 2.5% cobalt. It also has trace amounts of other elements like manganese, silicon, carbon, titanium, aluminium, and copper. This alloy’s unique composition gives it excellent oxidation and corrosion resistance at high temperatures.

Nickel: 62.0-69.0
Copper: Balance
Manganese: 4.0 max.
Titanium: 1.5-3.0
Iron: 2.5 max.
Silicon: 1.25 max.
Aluminum: 1.25 max.
Other: 0.50 max.
Carbon: 0.15 max.
Phosphorus: 0.02 max.
Sulfur: 0.015 max.

HAYNES® M418 RTW Coated Wire Mechanical Properties

HAYNES® M418 RTW welding alloy has unique mechanical properties that are ideal for high-temperature applications. Its tensile strength ranges from 165-185 ksi, and its yield strength ranges from 95-110 ksi. It also has good flexibility that allows it to withstand high-stress environments. Additionally, this alloy has a high fatigue strength and is resistant to creep deformation.

Tensile (psi) 70,000
Mpa 483
Elongation (%) 30

HAYNES® M418 RTW Welding Wire Physical Properties

The physical properties of HAYNES® M418 RTW welding metal also contribute to its performance in high-temperature applications. Its density is 8.4 g/cm³, and its specific heat capacity is 460 J/kg K. Its thermal conductivity ranges from 10.7-14.4 W/m K and its coefficient of thermal expansion ranges from 13.6-15.3 × 10^-6/K. These properties make HAYNES® M418 RTW a great choice for high-temperature applications.

HAYNES® M418 RTW Coated Wire Trade Name

Class UNS Haynes
ERNiCu-7 N04060 HAYNES® M418 RTW

HAYNES® M418 RTW Welding Wire Uses

HAYNES® M418 RTW welding wire is used in various industrial applications that require high temperature and corrosion resistance. It is commonly used in gas turbines, heat exchangers, and chemical processing equipment. Its high-temperature properties also make it ideal for use in jet engine components, like combustion chambers and afterburner parts. Additionally, it is used to produce nitric acid, which comes into contact with hot nitrogen oxides.

HAYNES® M418 RTW Coated Wire Corrosion Resistance

One of the key benefits of HAYNES® M418 RTW filler metal is its excellent corrosion resistance. It is highly resistant to oxidizing and reducing environments, making it ideal for use in harsh chemical environments. It resists attack by sulfuric acid, hydrochloric acid, and phosphoric acid. This alloy also resists attack by hot gases, including those produced by combustion.

HAYNES® M418 RTW Welding Wire Heat Treatment

HAYNES® M418 RTW filler wire is heat-treatable and can be strengthened by annealing and ageing. This involves heating the alloy to a specific temperature, holding it for a period, and then cooling it. This can improve the alloy’s tensile and yield strength without sacrificing flexibility or corrosion resistance.


HAYNES® M418 RTW is an innovative alloy with qualities ideal for high-temperature applications. Its durability, thermal conductivity, high tensile strength, and corrosion resistance make it a top choice for various applications. This nickel-based alloy can withstand harsh chemicals and extreme temperatures, making it the go-to choice for many industries. Understanding HAYNES® M418 RTW and its benefits will aid in selecting materials for your next project.

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