431 Stainless Steel-EN 1.4057

431 stainless steel (EN 1.4057) is a martensitic stainless steel that is heat-resistant and corrosion-resistant. It is typically used in applications where strength and durability are required.

431 stainless steel has excellent mechanical properties and is widely used in the aerospace, automotive, and oil and gas industries.

431 stainless steel also has good weldability, making it suitable for fabricating and repairing products made from this material.

431 Stainless Steel Material Specification

431 Stainless Steel Material Specification covers the chemical, mechanical and heat treatment conditions for this grade. The most common 431 Stainless Steel Material Specification are listed below:

  • ASTM A240
  • ASTM A276
  • ASTM A314
  • ASTM A479
  • AMS 5628
  • BS 970
  • EN 10088-2

431 Stainless Steel Equivalent

431 Stainless Steel is a martensitic stainless steel that was developed for superior machinability. 431 Stainless Steel Equivalent materials are:

  • EN 1.4057
  • DIN X17CrNi16-2
  • DIN X20CrNi17-2
  • AMS 5628
  • JIS SUS431
  • AMS 5628
  • SAE 431

431 Stainless Steel Chemical Composition

431 is a martensitic stainless steel that has been designed for superior machinability. The high chromium (15-17%) and nickel (1.5- 2.5%) content in 431 provides good corrosion resistance.

As with all martensitic grades, 431 offers excellent toughness and strength in the heat-treated condition. The addition of 1% silicon improves machinability. Complete chemical compositions for 431 stainless steel as per ASTM A240 is listed below.

431 Stainless Steel Chemical Compositions
Element Wt.%
 Carbon 0.20 max. 
 Manganese 1.0 max. 
 Phosphorus 0.040 max. 
 Sulfur 0.030 max. 
 Silicon 1.0 max.
Chromium  15.0- 17.0 
 Nickel  1.25- 2.50

431 Stainless Steel Mechanical Properties

431 stainless steel is a martensitic stainless steel that is AISI 431 grade. It has excellent corrosion resistance in moderate to high chloride environments, and good oxidation resistance at elevated temperatures.

Heat treatment can greatly affect the mechanical properties of 431 stainless steel. In the annealed condition, it is very ductile and can be cold-worked easily.

431 Stainless Steel

However, if it is heat treated to the hardenable temperature range, it will become much harder and less ductile.

The following table shows the mechanical properties of 431 stainless steel in the annealed condition.

431 Stainless Mechanical Properties in Annealed Condition
Property Valve
Yield Strength, Ksi (MPa)  95 (655)
 Tensile Strength, Ksi (MPa)  125 (862)
 Elongation % 20 minimum
Hardness Brinell ) 260

431 Stainless Steel Physical Properties

431 stainless steel is a martensitic stainless steel that possesses high tensile strength and hardness properties. As a heat-treatable grade, 431 stainless steel can be tempered to generate high strength.

Out of the family of austenitic steels, 431 stainless steel has the highest chromium content – 15-17% by weight.

By virtue of this higher chromium percentage, 431 stainless steel delivers improved corrosion resistance compared to its lower carbon rivals 410 and 420 Martinistic grades.

In addition to improved corrosion resistance, 431 stainless steel also offers greater toughness and impact resistance.

The physical properties of 431 stainless steel are:

  • Density: 7.8 g/cm3
  • Coefficient of Thermal Expansion (μm/m/°C) @ 0-100°C: 10.2
  • Thermal Conductivity (W/m.K): 20.2
  • Melting temperature: 2595-2750°F (1424-1510°C)

431 Stainless Steel Corrosion Resistance

431 Stainless Steel is a martensitic stainless steel that is known for its impressive corrosion resistance.

This grade of steel is significantly higher in terms of corrosion resistance when compared to other martensitic stainless steels, but it still falls behind austenitic stainless steel grades.

431 stainless steel is a martensitic stainless steel that possesses high tensile strength and power. It also has great corrosion resistance, making it ideal for use in a wide range of industries and applications.

Some of the most common industries that use 431 stainless steel are food processing, chemical processing, and marine environments. 431 stainless steel also has excellent resistance to abrasion and wear, making it ideal for high-stress applications.

431 Stainless Steel Welding

431 stainless steel is a martensitic stainless steel that offers superior weldability compared to other types of stainless steel.

  • 431 stainless steel is a ferritic, martensitic, heat-treatable steel with very good weldability. The main reason for its good weldability is its low carbon content.
  • 431 can be welded using any standard welding process including Tig, Mig, and Stick welding. However, care should be taken to not overheat the material during welding as this can lead to cracking.
  • The recommended preheat temperature for 431 stainless steel is between 200-300°C. This will help to prevent cracking and ensure a strong weld joint.
  • When welding 431 stainless steel using ER410 wire, it is important to use a properly sized tip on your welder.

Machining

431 is a 16% chromium-high nickel-content martensitic stainless steel that is used primarily for shafting and other applications that require high strength and good corrosion resistance.

431 has the best machining characteristics of all the stainless steels, and is capable of very good precision machining in the annealed condition. However, in the hardened and tempered condition it is difficult to machine, due to its high hardness and lack of ductility.

Click here for 431 stainless steel Welding Guidelines.


Why Is Stainless Steel Called Stain...
Why Is Stainless Steel Called Stainless?