Mechanical Properties of Cr-Ni-Mn-N Austenitic Stainless Steel 0Cr21Ni6Mn9N(Nitronic40) at Room Temperature

Mechanical Properties of Nitronic 40 (0Cr21Ni6Mn9N) Austenitic Stainless Steel at Room Temperature

Introduction

Nitronic 40 (0Cr21Ni6Mn9N) is an austenitic stainless steel with an alloy composition that is primarily composed of chromium, nickel and manganese. Its unique combination of properties make it suitable for a wide range of industrial applications. It offers excellent corrosion resistance, good formability and weldability, as well as high strength and hardness. In addition, Nitronic 40 provides excellent resistance to abrasive wear, erosion and galling. As a result, it is a popular choice for many industrial components exposed to severe wear and corrosion.

In order to effectively select and apply Nitronic 40 for a particular application, it is necessary to understand its mechanical properties at room temperature. This paper outlines the mechanical properties of Nitronic 40 austenitic stainless steel at room temperature.

Tensile Strength

The ultimate tensile strength of Nitronic 40, measured using standard methods, ranges from 880 to 1290 MPa. The yield strength of the alloy varies between 490 and 945 MPa. The modulus of elasticity or Youngs modulus, which measures the stiffness of the material, is around 190 GPa.

Impact Resistance

Nitronic 40 is a tough austenitic stainless steel, possessing good impact resistance even at temperatures as low as -100ºC. The toughness of the alloy can be further improved by tempering at temperatures around 500ºC. The Charpy V-notch impact test results of Nitronic 40 show an average energy absorption of 40J or higher.

Hardness

The hardness of Nitronic 40 is dependent on heat treatment conditions as well as the alloy composition. In the case of as-received condition, the Rockwell C (HRC) hardness of the alloy usually ranges from 32 to 36 HRC. Through heat treatment, the hardness of Nitronic 40 can be increased to around 41 HRC.

Corrosion Resistance

Nitronic 40 exhibits excellent resistance to corrosion from numerous environments. It displays good resistance to fresh and saltwater, as well as most organic acids. Nitronic 40 does not undergo crevice or stress-corrosion cracking even when exposed to chloride-containing environments. Additionally, it offers exceptional resistance to pitting, intergranular and sulfide stress-corrosion cracking.

Conclusion

Nitronic 40 is a high-performance austenitic stainless steel that offers excellent corrosion resistance, good formability and weldability, as well as high strength and hardness. Its mechanical properties at room temperature include ultimate tensile strength of 880-1290 MPa, yield strength of 490-945 MPa and Youngs modulus of 190 GPa. Nitronic 40 also has good impact resistance and hardness of up to 41 HRC. Its excellent corrosion resistance makes it suitable for use in a variety of harsh environments.

Nitronic 40 (UNS S21900/0Cr21Ni6Mn9N) is a high nitrogen Nitronic austenitic stainless steel. It was first developed by Allegheny Technologies, Inc. It provides superior corrosion resistance along with excellent pitting resistance, crevice corrosion resistance, stress corrosion cracking resistance, formability and toughness.

At room temperature (25°C / 77°F), Nitronic 40 has a typical material hardness of

~ 280-320 HV (Vickers Hardness Value). It has an ultimate tensile strength of 600-788 MPa (87-114 ksi) and yield strength of ~ 350-380 MPa (51-55 ksi). Its elongation at break is ~ 15-20%, and its fatigue strength at 500,000 load cycles is ~ 420-490 MPa (60-71 ksi). It has a modulus of elasticity of ~ 193 GPa (28 × 10^6 psi), and a thermal conductivity of ~ 17.60 W/(m·K) (Btu·in/(ft·h·°F)). The coefficient of thermal expansion (CTE) is ~ 17.3 μm/(m·K) (9.8 · 10^-6 in/(in·°F)). It has a thermal diffusivity of ~ 18.7 mm²/s.

Nitronic 40 has excellent formability, making it a great choice for components which require cold forming or draw forming. Applications include pump shafts, bearings and other components exposed to marine environments, food processing equipment, and other components which require both superior corrosion resistance and high strength.