CA40 martensitic stainless steel


Overview of CA40 Martensitic Stainless Steel

It is an exceptional choice for knives and tools requiring corrosion resistance, owing to its high chromium content and martensitic stainless steel composition. This material can be hardened by heat treatment and offers excellent performance in applications exposed to atmosphere, steam, water or oxidizing acids. Notably, It was the world’s first stainless steel, making it a reliable option for countless projects and applications.

The characteristics of martensitic stainless steel CA40

  • Very high hardness.
  • Low cost.
  • It has good corrosion resistance in atmospheric corrosion and milder corrosive media (such as water and some organic media).
  • magnetic.
  • It has good mechanical properties, the strength index is more than twice that of austenitic stainless steel, and it also has good welding performance.
A743 Ca40 metallographic structure
A743 Ca40 metallographic structure

Ca40 Material composition

Carbon:                                   0.20-0.40

S:                                             0.04 MAX

P:                                             0.04 MAX

Mo:                                          0-0.5     

Chromium:                            11.5-14.0

Manganese:                          1.00 MAX

Nickel:                                    1.00 MAX

Silicon:                                   1.5

Ca40 Physical properties

Mechanical PropertiesOriginal Value
Tensile Strength, Ultimate >= 690 MPa 
Tensile Strength, Yield >= 485 MPa 
Elongation at Break >= 15 %

Stainless Steel Ca40 Applications

It is a versatile alloy commonly used in a variety of applications. It is especially valued for its corrosion resistance and high strength.

This alloy is commonly used in bearings, chemical and food equipment, knives, medical equipment, turbine engine components, bushings, aerospace, pump, and valve components. It is also used in decorative items such as railings and handrails. The strength of this alloy makes it ideal for construction and agricultural applications.

It is also used in construction projects such as bridges and buildings due to its superior strength and corrosion resistance. Due to its heat-resistant properties, this alloy is also frequently used in the automotive industry.

Overall, It is a versatile alloy with a variety of applications. It is highly valued for its strength and corrosion resistance, making it a popular choice in many industries.

ASTM A743 CA40 equivalent

DIN 17445 G-X20Cr14; JISG 5121 SCS2; A743 Ca40; Z22Cr13M; 20X13Π; 420C28; ZG20Cr13

CA40 Related standards

ASTM A743/A743M  Standard Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application

Heat Treatment Requirements:

Castings of the CA40 alloy should be heated to at least 1450°F (788°C) before cooling slowly in a furnace. The alloy should then be hardened by heating it to between 1800 to 1850°F (982 to 1010°C) before quenching in oil or air, followed by tempering at 600°F (316°C) or lower. The highest strength and hardness are acquired by tempering at 600°F (316°C) or lower, and the alloy has the best corrosion resistance in this fully heat-treated condition.