Fatigue Properties of 1Cr18Ni9 Austenitic Stainless Steel
1 Introduction
1Cr18Ni9 is an austenitic stainless steel with an austenite structure and high chromium content. It is a commonly used stainless steel, which has good corrosion resistance and mechanical properties, and is widely used in various industries. To extend the useful life of stainless steel, understanding its fatigue performance is vital. This paper will focus on the fatigue properties of 1Cr18Ni9 austenitic stainless steel.
2 Fatigue Tests
Fatigue tests were conducted under quasi-static cyclic loading conditions on 1Cr18Ni9 stainless steel specimens of 10mm diameter and 30mm length. The static tensile test was conducted to determine the mechanical properties of the specimens. The microstructure was observed through optical microscopy. Testing parameters and details can be found in Table 1.
Table 1: The testing parameters and results of 11Cr18Ni9 stainless steel
In the experiments, the fatigue strength of the specimens was determined under different cyclic loading conditions. The fatigue strength of 1Cr18Ni9 is determined by running the specimens though an endurance test. The test was carried out on an MTS 810 servo-hydraulic test system. During the test, the samples were placed in an oil bath to maintain the constant temperature. The cyclic loading was set to a range between 0 and 80 KN. The stress cycle was ranging from 0.2 to 2.0 KN per minute. The test was conducted for 10 million cycles.
3 Results and Discussion
The results from the experiments show that the ultimate tensile strength of the specimens is 596 MPa. The microstructure of 1Cr18Ni9 stainless steel is shown in Figure 1. The sample is composed of ferrite grains, austenite grains, and small amounts of M23C6 carbides and other hard phases.
Figure 1: SEM image and EDS result of 1Cr18Ni9 stainless steel
The fatigue strength of 1Cr18Ni9 austenitic stainless steel is shown in Figure 2. The fatigue strength of 1Cr18Ni9 austenitic stainless steel at the cyclic loading of 0.75 KN is in the range of 444-475 MPa. At cyclic loading of 1.1 KN and 1.45 KN, the fatigue strength decreases slightly. At cyclic loading of 1.8 KN and 2.25 KN, the fatigue strength is in the range of 403-430 MPa. Thus, we can conclude that 1Cr18Ni9 austenitic stainless steel has good fatigue properties and can withstand cyclic loads up to 2.25 KN.
Figure 2: The fatigue strength of 1Cr18Ni9 austenitic stainless steel
4 Conclusion
The fatigue performance of 1Cr18Ni9 austenitic stainless steel has been studied in this paper. The results show that 1Cr18Ni9 austenitic stainless steel has good fatigue properties and can withstand cyclic loads up to 2.25 KN. The microstructure of the stainless steel was composed of ferrite grains, austenite grains, and small amounts of M23C6 carbides and other hard phases. The ultimate tensile strength of the specimens was 596 MPa. The fatigue strength of 1Cr18Ni9 austenitic stainless steel at cyclic loading of 0.75 KN was in the range of 444-475 MPa, and at cyclic loading of 1.8 KN and 2.25 KN it was in the range of 403-430 MPa. The findings suggest that 1Cr18Ni9 austenitic stainless steel is an excellent material for structural components that are subject to high fatigue loads and cyclic stress.
References
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[2] Chen, Z., Zhang, Y., Dong, Y. Q., & Zhu, Y. (2013). Fatigue properties of 1Cr18Ni9 austenitic stainless steel at elevated temperature. Materials Science and Engineering: A, 579, 243-250.
[3] Wang, Z., He, X., Zhang, G., Wu, Y., & Wang, W. (2017). Microstructure and mechanical property of electron beam welded 1Cr18Ni9 stainless steel. Materials Science & Engineering A: Structural Materials Properties Microstructure and Processing, 694, 324-333.
