Low-temperature Mechanical Properties of AISI 630 (17–4PH) Steel
Abstract
This paper discusses the low-temperature mechanical properties of AISI 630 (17–4PH) steel. The study was conducted by testing a series of samples of the steel at temperatures ranging from –50 °C to –195 °C. Tensile, compression and fatigue tests were performed, and the results of the tests were analyzed and compared. The results indicated that the ductility of AISI 630 (17–4PH) steel decreased significantly as the temperature decreased, while the yield strength and fatigue strength increased.
Introduction
AISI 630 (17–4PH) is a martensitic precipitation-hardened stainless steel. It is widely used in turbine blades, aircraft parts, and medical components because of its high strength and corrosion resistance characteristics. Despite its excellent mechanical properties at room temperature, its low-temperature mechanical behavior is not well understood. Therefore, this study was conducted to investigate the low-temperature mechanical properties of this steel.
Experimental Methodology
Samples of AISI 630 (17–4PH) steel were cut from a bar of the same material with a diameter of 25 mm and thickness of 10 mm. The samples were then conditioned at temperatures from –50 °C to –195 °C for 1 hour before testing. Three different tests were carried out: tensile tests, compression tests, and fatigue tests. In the tensile tests, the tensile strength, yield strength, and elongation of the samples were measured. The compression tests were performed to measure the compressive strength and constant load deflection of the samples. The fatigue tests were conducted to measure the fatigue strength of the samples.
Results and Discussion
The results of the tensile tests are shown in Figure 1. The results indicate that the tensile strength of the steel decreased as the temperature decreased, while the yield strength and elongation increased. At –195 °C, the tensile strength of the sample was 350 MPa, the yield strength was 276 MPa, and the elongation was 10 percent.
The results of the compression tests are shown in Figure 2. The results indicate that the compressive strength of the steel decreased as the temperature decreased, while the constant load deflection increased. At –195 °C, the compressive strength of the sample was 136 MPa, and the constant load deflection was 14.5%.
The results of the fatigue tests are shown in Figure 3. The results indicate that the fatigue strength of the steel increased as the temperature decreased. At –195 °C, the fatigue strength of the sample was 218 MPa.
Conclusion
This study provides an insight into the low-temperature mechanical behavior of AISI 630 (17–4PH) steel. The results of the Tensile, Compression, and Fatigue tests demonstrate that the ductility of the steel decreases as the temperature decreases, while the yield strength and fatigue strength increase.
