Analisis Kegagalan Pada Komponen Poros Pompa Industri

Pumps are very important industrial equipment in the petroleum industry. The component that often fails is the pump shaft. Therefore, it is necessary to conduct a failure analysis of this component to determine the mode/type of failure and how it occurred. This study used Scanning Electron Microscope (SEM), metallographic test, chemical composition test, and Brinell hardness test with the standard UNSS42000 material. Fatigue test to determine the fatigue limit of the shaft with a rotary bending fatigue test. The failure model that occurred was fatigue failure characterized by initial cracks, crack growth, ratchet marks, sudden fracture areas. Based on the comparison between the test results of chemical composition and mechanical properties of the material, the drive shaft pump material was suitable for the UNS S42000 material.

Quantitative Examination of the Inclusion and the Rotated Bending Fatigue Behavior of SAE52100

This study investigated the effect of maximum inclusion on the life of SAE52100 bearing steel processed by two different melting routes, vacuum induction melting plus electroslag remelting (VIM + ESR), and basic oxygen furnace plus ladle furnace plus vacuum degassing process (BOF + LF + RH) by the metallographic method, Aspex explorer, and rotated bending fatigue test. The rotated bending method was applied to examine the maximum inclusion size in a satisfactory manner, whereas both the metallographic method and Aspex explorer underestimated the result. Regardless of the characterization methods, the results show that the total number of inclusions in VIM + ESR melted steel is significantly higher than that in BOF + LF + RH processed steel, but the maximum inclusion size of VIM + ESR melted steel is significantly smaller than that of the BOF + LF + RH degassed steel. The distribution of the maximum inclusion size could be well fitted by the inverse Weibull distribution and could be well applied to reveal the different inclusion size distribution based on the data examined by the rotated bending fatigue method. Finally, a new equation was proposed to establish the relationship among the loading stress amplitude, rotated bending fatigue number, and the maximum inclusion size.

Heat treatment effect on fatigue behavior of 3D-printed maraging steels

Purpose This study aims to reveal that fatigue life is improved using heat treatment in the rotational bending fatigue test, which determines the fatigue behavior closest to service conditions. Design/methodology/approach It is essential to know the mechanical behavior of the parts produced by additive manufacturing under service conditions. In general, axial stress and plane bending tests are used by many researchers because they are practical: the service conditions cannot be sufficiently stimulated. For this reason, the rotating bending fatigue test, which represents the conditions closest to the service conditions of a load-bearing machine element, was chosen for the study. In this study, the rotational bending fatigue behavior of X3NiCoMoTi18-9–5 (MS1) maraging steel specimens produced by the selective laser melting (SLM) technique was experimentally investigated under various heat treatments conditions. Findings As a result of the study, MS1 produced by additive manufacturing is a material suitable for heat treatment that has enabled the heat treatment to affect fatigue strength positively. Cracks generally initiate from the outer surface of the sample. Fabrication defects have been determined to cause all cracks on the sample surface or regions close to the surface. Research limitations/implications While producing the test sample, printing was vertical to the print bed, and various heat treatments were applied. The rotating bending fatigue test was performed on four sample groups comprising as-fabricated, age-treated, solution-treated and solution + age-treated conditions. Originality/value Most literature studies have focused on the axial fatigue strength, printing orientation and heat treatment of maraging steels produced with Direct Metal Laser Sintering (DMLS); many studies have also investigated crack propagation behaviors. There are few studies in the literature covering conditions of rotating bending fatigue. However, the rotating bending loading state is the service condition closest to modern machine element operating conditions. To fill this gap in the literature, the rotating bending fatigue behavior of the alloy, which was maraging steel (X3NiCoMoTi18-9–5, 1.2709) produced by SLM, was investigated under a variety of heat treatment conditions in this study.

Fatigue Performance of an Additively Manufactured Zr-Based Bulk Metallic Glass and the Effect of Post-Processing

Fatigue is the most common cause of failure of mechanical parts in engineering applications. In the current work, we investigate the fatigue life of a bulk metallic (BMG) glass fabricated via additive manufacturing. Specimens fabricated via laser powder-bed fusion (LPBF) are shown to have a fatigue ratio of 0.20 (fatigue limit of 175 MPa) in a three-point bending fatigue test. Three strategies for improving the fatigue behavior were tested, namely (1) relaxation heat treatment, giving a slight fatigue life improvement at high loading conditions (≥250 MPa), (2) laser shock peening, and (3) changing the build orientation, the latter two of which yielded no significant effects. It was found that the presence of lack of fusion (LoF) had the preponderant effect on fatigue resistance of the specimens manufactured. LoF was observed to be a source of stress localization and initiation of cracks. The fatigue life in BMGs fabricated by LPBF is thus primarily influenced by powder quality and process-induced defects, which cannot be removed by the post-treatments carried out in this study. It is believed that a slight increase in laser power, either in the near-surface regions or in the core of the specimens, could improve the fatigue behavior despite the associated (detrimental) increase of crystallized fraction.

Tribo-fatigue characteristics of braided wire rope for traction under low cycle bending fatigue

Braided wire rope as the traction tool is indispensable for stringing conductors in overhead transmission lines. However, rope body wear and fatigue fracture failure often lead to its premature scrap. In this paper, the bending fatigue test of YS 9-8 × 19 braided wire rope for traction was carried out by the test rig. The bending fatigue life of the braided wire rope was discussed by the number of broken wires. Furthermore, the fracture mechanism and wear morphology of the rope wires were analyzed by Ultra-depth three-dimensional microscope combined with the scanning electron microscope. The fatigue damage mechanism was discussed, and the tribo-fatigue characteristics of the wire rope were investigated. Results show that the failure of braided wire rope is the result of the interaction of cyclic bending stress and surface damage. Moreover, most broken wires occur at the place where the rope wires are severely worn. When the bending fatigue cycle is between 2.0 × 104–2.4 × 104, the number of broken wires reaches the scrap standard. Additionally, the bending tribo-fatigue damage of the wires between adjacent strands is the most serious. The primary wear mechanisms of the wires in contact with the pulley are fatigue wear and abrasive wear. In contrast, the wires between adjacent strands are affected by fatigue wear, adhesive wear, and tribo-oxidation.

The Development of Pneumatic Fatigue Test Rig for Wood-Based Specimens

In product design, the focus is increasingly shifting towards optimizing and increasing the efficiency of the development process. This can be achieved with advanced numerical tools, but these methods require precise knowledge of material properties. One of the desired properties is the dynamic load behavior of the material. The research is directly related with the company that developed the slender wooden beams used in industry to produce windows of larger dimensions (height over 3 m). For the testing of wooden beams, the pneumatic four-point bending fatigue test rig was developed. In this paper, the whole structure of the test rig is described in detail. Based on the performed experiments of dynamic strength, the Woehler curve was determined, which serves as a necessary input for further numerical simulation of the fatigue process of wood-based beams. Knowledge of the response of wood to dynamic loads is very important to predict its life expectancy in various products.

Study on Fatigue Test and Life Prediction of Polyurethane Cement Composite (PUC) under High or Low Temperature Conditions

There are many diseases in the deck pavement of long-span steel bridges under the action of vehicles, rainwater, and freezing. It is necessary to study a new type of pavement material with high waterproof property, light weight, and high bonding performance for steel deck pavement. Polyurethane cement composite (PUC) can be used for steel deck pavement. In order to find out the temperature effect on fatigue properties of PUC, the four-point bending fatigue test was carried out at different temperatures. In this paper, the optimum mix ratio of PUC was selected by compressive and flexural tests, and then the bending fatigue test was conducted under strain control mode. Under temperature and external force coupling condition, a method for predicting fatigue life of PUC is proposed by the combination of theoretical deduction and experimental research. The results show that the proposed formula can effectively describe the fatigue life and fatigue limit of PUC. Finally, compared with three different asphalt mixtures for steel deck pavement, it is found that the fatigue performance of polyurethane cement is better than that of asphalt mixture.