Failure Analysis of A Welded Mild Steel Shaft Under Tensile Loading Condition

Welding is a process of permanently joining two or more parts by the application of heat and (or) pressure and is the widely used process in fabrication, maintenance and repairs of parts and structures. Almost 70 percent of all manufactured products are made with the skills of welders. In the field of Mechanical Engineering the modern welding trends and advanced products are made with the skills of welders. In the field of Mechanical Engineering the modern welding trends and advanced welding process has been contributing toward advancement, a study has been given greater priority of failures analysis of welding joints and various structural and technical aspects have an impact on fracture characteristics of welded joints. The welded joints and various structural aspects have an impact on fracture characteristics of welded joints. The objectives of this work were to investigate the tensile behavior of welded mild steel shaft to analyzing the failure analysis of welded joints for that purpose step joint, lap joint, double v joint, double v pin joint and double j joint specimens of standard size were developed. Each specimen was machined, welded and finished at its center. A tensile test was performed on all the welded shaft of mild steel. Tensile test has been carried out by Universal Testing Machine, after testing the specimens, it was found that the welded shaft with Lap Joints bears the Maximum Tensile Strength.

Calculation of a joint with two key-steels

A connection with two key-steels located on the same diameter and the determination of the forces acting on the key-steels are considered. Keywords: key-steel, shaft, hub, force. [email protected]

Torque at elastic-plastic torsion of sheet-straightening machines’ steel shafts

The experiments on the torsion of the steel shaft were conducted on the machine Instron 55MT2 with a maximum torque of 220 N×m and a mass of 2500 N. The ends of the shaft clamped with collet-chucks. For the torsion we used the round cylindrical samples from a low-carbon steel with the Young’s modulus of 2×1011 Pa, the shear modulus of 7.752×1010 Pa, the Poisson’s ratio of 0.29, the yield strength of 524 MPa, the yield strength at shift of 302 MPa, the ultimate shear stress of 352 MPa, the ultimate shift of 0.18 and the plastic module at shift of 740 MPa. The torsion of the steel shafts and thick-walled pipes is widely used in the metallurgy, mechanical engineering and oilgas industry. For example, the shafts’ torsion is observed in the drive mechanisms of the sheet-straightening machines for the thin and thick steel sheets, in the rolling mills for the cold and hot steel sheets, in the drives of the rear wheels of motor transport, in the land and sea gas-oil drilling platforms and so on. Under the significant torque, the steel shafts can experience not only elastic, but also plastic deformation without the destruction. The experimental dependence of the shaft torque on the twisting angle gives researchers much more information about the mechanical properties of steel than the analogous experiments on the rupture of the steel shafts, since there is no neck formation during the torsion and the steel shaft does not collapse even at the very large twisting angles. The classical Ludwik’s and Nadai’s approximations for shear do not sufficiently accurately describe the shear deformation and are, therefore, not sufficiently effective for calculating the shaft torque. Therefore, the more accurate the straight and back Shinkin’s approximations are used below to describe the shear deformation. A special feature of calculating the dependence of the shaft torque on the shear angle is that the torque is calculated approximately as a power series, since the corresponding integrals are transcendental (cannot be calculated analytically). At the same time, the relative accuracy of the torque calculation is very high (about 10-6 %).

Tribo-Mechanical Characterization of Carbon Fiber-Reinforced Cyanate Ester Resins Modified With Fillers

High-performance polymer composites are being increasingly favored for structural applications. For this purpose, efforts are being focused on exploring the potential of high-performance thermoplastics and thermosets. Cyanate ester (CE) resin is a special thermoset that can be used at up to 400 °C without any considerable degradation; however, its tribological properties are not at the adequate level. Hence, it is needed to use this polymer in composite form with the fibrous/particulate reinforcement to impart better tribological properties and mechanical strength via a strong fiber–matrix interface. Carbon fiber/fabrics are at the forefront as reinforcement for specialty polymers. The tribological and tensile properties of cyanate ester (CE) composites-filled graphite, polytetrafluoroethylene (PTFE), and MoS2 micron-sized fillers reinforced with carbon fibers (CF) are investigated experimentally in a block-on-ring setup at 100 N, for 10 h, and with a sliding distance of approximately 10,000 m, against a hardened polished 100Cr6 steel shaft and diamond-like-coated (DLC) 100Cr6 steel shaft. The tribological properties of the composites including the coefficient of friction and specific wear rate are enhanced especially with the incorporation of graphite fillers. The friction coefficient and wear rate of the graphite-based composite was decreased significantly at 5 wt.% of graphite concentration. Further, at the same concentration, the graphite-based composite showed superior tensile properties as compared to the reference system owing to better dispersion and adhesion between the fibers and matrix. Tensile tests are performed to characterize the fiber–matrix interfacial adhesion and other strength properties.

Studying Adhesion between a 67Ni18Cr5Si4B Alloy Powder Coating Produced with the High Velocity Oxygen Fuel Thermal Spray Method HVOF and a Substrate Surface of a Worn C45 Steel Shaft

Nowadays, thermal spray coatings are used to enhance mechanical properties of the material. One of the technologies used to produce thermal spray coating is HVOF spray technology. This is the most advanced and modern technology which has been widely used in the industry due to its flexibility and ability to create coatings with better adhesion in comparison with other thermal spray methods. This article presents some empirical findings from applying the 67Ni18Cr5Si4B alloy powder coating onto C 45 steel shaft by HVOF spray technology. It also analyzes the influence of some technological parameters on the adhesion of the coating. As a result, the parameters of HVOF spray technology are obtained suitable for recovering worn axis-sized workpieces.