Monel® R-405 / N04405

Nickel alloy 405 is a nickel-copper alloy with high toughness and strength. It also has excellent corrosion resistance in a range of media that include alkalis, sulfuric acid, hydrofluoric acid and seawater. The alloy has enhanced machinability due to its increased sulfur content. It can be slightly magnetic at room temperature, and has excellent resistance to chloride ion stress corrosion cracking.

Monel R405 is the free machining version of Monel 400. It is a nickel-copper alloy with a controlled amount of sulfur added to provide sulfide inclusions that act as chip breakers during machining. Like Monel 400, alloy R-405 is resistant to sea water and steam at high temperatures as well as to salt and caustic solutions. Monel R405 is a solid solution alloy that can only be hardened by cold working. This nickel alloy exhibits characteristics like good corrosion-resistance, good weldability and high strength.

Other Designations

Other designations that are equivalent to nickel alloy 405 include the following:

• ASTM B 164
• ASME SB-164
• SAE AMS 4764
• SAE AMS 7234
• QQ-N-281
• NACE MR-01-75

In what forms is Monel R405 Available at SAGAR STEELS ?

• Round Bar (ASTM specification B 164)
• Hex Bar

Corrosion Resistant Monel R-405

As with alloy 400, Monel R-405 is virtually immune to chloride ion stress corrosion cracking in typical environments. Generally, its corrosion resistance is very good in reducing environments, but poor in oxidizing conditions. It is not useful in oxidizing acids, such as nitric acid and nitrous. Nevertheless, it is resistant to most alkalis, salts, waters, food products, organic substances and atmospheric conditions at normal and elevated temperatures.

Monel 400 and R-405 offer about the same corrosion resistance as nickel but with higher maximum working pressures and temperatures and at a lower cost due to its superior ability to be machined.

What are the characteristics of Monel R405?

Characteristics are essentially the same as those of Monel 400 such as:

• Good machinability and is recommended for use with automatic screw machines
• Resistant to seawater and steam at high temperatures
• Excellent resistance to rapidly flowing brackish water or seawater
• Excellent resistance to stress corrosion cracking in most freshwaters
• Particularly resistant to hydrochloric and hydrofluoric acids when they are de-aerated
• Offers some resistance to hydrochloric and sulfuric acids a modest temperatures and concentrations, but is seldom the material of choice for these acids
• Excellent resistance to neutral and alkaline salt
• Resistance to chloride induced stress corrosion cracking
• High resistance to alkalis

Chemical Composition, %

In what applications is Monel R-405 used?

Alloy R-405 is chiefly used for automatic-screw-machine stock and it not generally recommended for other applications. Screw machine stock for fasteners and similar high production run items.

• Meter and valve parts
• Fasteners
• Screw machine products

Fabrication with Monel R-405

Monel R-405 is fabricated, pickled and heat-treated by the same procedures as for alloy 400. It is not recommended for forging. However, R-405 alloy was especially developed for good machinability and is recommended for use with automatic screw machines. The nickel –copper sulfides resulting from the sulfur in its composition act as chip breakers.

This nickel alloy also has the same procedures and processes as alloy 400 and can be joined by standard welding, brazing and soldering techniques. Just as with alloy 400, R-405 can easily be welded by gas – tungsten arc, gas metal arc, or shielded metal arc processes using appropriate filler metals. There is no need for post weld heat treatment, however, thorough cleaning after welding is critical for optimum corrosion resistance, otherwise there is the risk of contamination and embrittlement.

Physical Properties

The following table shows the physical properties of nickel alloy 405.

Properties	Metric	Imperial
Density	8.80 g/cm3	0.318 lb/in3
Melting point	1300-1350°C	2370-2460°F

 

Mechanical Properties
Nominal Mechanical Property Range of Monel Alloy R-405 Rod and Bar

The ranges shown are composites for various product sizes and therefore are not suitable for specification purposes.

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