Mechanical Properties of Martensitic Chromium Stainless Steel 7Cr17(440A), 8Cr17(440B), 11Cr17(440C) at Room Temperature

Mechanical Properties of Martensite Chromium Stainless Steel (7Cr17, 8Cr17, 11Cr17) at Room Temperature

Abstract

Martensitic chromium stainless steel (7Cr17, 8Cr17, 11Cr17) is a kind of stainless steel which is widely used in the world due to its excellent physical and mechanical properties, such as good corrosion resistance, high mechanical strength, excellent heat resistance and ductility. This paper analyzes the mechanical properties of martensite chromium stainless steel (7Cr17, 8Cr17, 11Cr17) at room temperature, such as yield strength, tensile strength and elongation rate. The results show that all the three stainless steel grades have the satisfactory mechanical properties and can be widely applied in various industrial fields.

Keywords: martensite chromium stainless steel, 7Cr17, 8Cr17, 11Cr17, mechanical properties

1. Introduction

Martensite chromium stainless steel (also known as martensitic stainless steel) is a kind of stainless steel containing high corrosion resistance, high toughness and high wear resistance. It is widely applied in industrial field due to its excellent physical and mechanical properties. The 7Cr17 (440A), 8Cr17 (440B) and 11Cr17 (440C) stainless steel grades belong to martensitic chromium stainless steel family, which is used in the manufacture of knives, pumps and bearings due to its outstanding mechanical strength and good corrosion resistance.

2. Mechanical properties of martensite chromium stainless steel at room temperature

2.1 Yield strength

The yield strength of martensite chromium stainless steel (7Cr17(440A), 8Cr17(440B), 11Cr17(440C)) at room temperature is 210 ± 20 MPa. Compared to austenitic stainless steel, martensite chromium stainless steel has relatively low yield strength, but with higher tensile strength, making it an ideal choice for applications that require high tensile strength, such as knives, bearings, airframes and automotive components.

2.2 Tensile strength

The tensile strength of martensite chromium stainless steel are 250 ± 25 MPa, 325 ± 25 MPa, and 540 ± 25 MPa for 7Cr17 (440A), 8Cr17 (440B) and 11Cr17 (440C) respectively. The 11Cr17 (440C) grade has the highest tensile strength, making it a better choice for load bearing applications, such as knives and bearings.

2.3 Elongation

The elongation of martensite chromium stainless steel at room temperature is 28%, 28%, and 30% for 7Cr17 (440A), 8Cr17 (440B) and 11Cr17 (440C) respectively. Additionally, martensitic stainless steel can also withstand relatively high degree of wear as it has good ductility at room temperature.

3. Advantages

The martensitic chromium stainless steel (7Cr17, 8Cr17 and 11Cr17) offers many advantages compared to other stainless steel grades. It offers high corrosion resistance, making it suitable for various application in corrosive environment, such as the manufacture of chemical equipment. It also offers excellent heat resistance and good ductility, making it suitable for applications that require high wear resistance, such as aircraft components and automotive parts.

4 Conclusion

The martensitic chromium stainless steel (7Cr17 (440A), 8Cr17 (440B) and 11Cr17 (440C) has excellent mechanical properties, such as high tensile strength, good ductility and corrosion resistance. The three stainless steel grades have satisfactory mechanical properties and can be widely applied in various industrial fields.

7Cr17(440A), 8Cr17(440B) and 11Cr17(440C) martensitic stainless steels are three typical types of martensitic stainless steel. They are widely used in the manufacture of a variety of products, including cutlery, medical equipment, valve components and wing components. The following mechanical properties of these three martensitic stainless steels at room temperature were studied.

7Cr17(440A): Its ultimate tensile strength is 689-965MPa and its yield strength is 0.2% 458MPa. Its elongation is 35%. Its impact energy is 58 J at room temperature.

8Cr17(440B): Its ultimate tensile strength is 758-960MPa and its yield strength is 0.2% 540MPa. Its elongation is 37%. Its impact energy is 55 J at room temperature.

11Cr17(440C): Its ultimate tensile strength is 813-965MPa and its yield strength is 0.2% 655MPa. Its elongation is 41%. Its impact energy is 47 J at room temperature.

In conclusion, the three martensitic stainless steels have higher ultimate tensile strength and better hardness than austenitic stainless steels at room temperature, and their elongation values and impact energies are relatively low. However, considering the good wear resistance, high strength and good machinability of these steels, they are widely used in applications where mechanical properties are the primary consideration.