Study on Tensile Strength of SS304 Steel Weld Joint with Different Bevel Angles

Welding is one of the most universal type of joining method used in the industry especially oil and gas industry. Good welding of pipe is crucial as bad welding can lead to cracks and failures. One of the parameter that affects the quality of weld is the bevel angle for single V butt joint weld. This paper aims to analyse the effect of different included bevel angle of SS304 stainless steel pipe weld. Simulation was performed in ANSYS which showed that 50 degree bevel angle is the optimum bevel angle for single V butt joint for SS304 steel with 13mm thickness. To verify the simulation result, experiment was performed. The type of welding process that was used to perform the weld was Gas Tungsten Arc Welding (GTAW), also known as Tungsten Inert Gas (TIG) welding. The SS304 stainless steel was first sectioned and milled in order to achieve different bevel angle before being welded using TIG welding and machined again in order to perform tensile test. Tensile test was performed according to ASTM E8 standard in order to determine the strength of the welded pipe. Based on the values obtained from the tensile test such as Yield Strength and Ultimate Tensile Strength (UTS), the optimum bevel angle for single V butt joint is 50 degree. Keywords: TIG welding process, SS 304 stainless steel plate, tensile test

Form measurements of micro-holes

The form measurement and gauge repeatability and reproducibility (R&R) of a micro-hole using a coordinate measurement machine (CMM) with a combination of optical and contact sensors were conducted in this study. The micro-holes, about 160 µm in diameter and 0.9 mm in depth, were fabricated using the electrical discharge machining process for diesel fuel injectors. The shape and size of micro-holes are important for the desired spray pattern, fuel economy and exhaust emission of diesel engines. In this study, the setup of the measurement machine and the procedure to determine the contact points are presented. Five form characteristics, the cylindricity, diameter, roundness, straightness and taper, of the micro-hole are analyzed from measurement points. The gauge R&R test is conducted to determine the micro-hole form measurement capability and to calculate the tolerance specifications for each characteristic that the CMM is capable of measuring. An example to quantify the change in the shape of the micro-holes before and after the abrasive flow machining is presented.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/58130/2/mst7_11_045.pd

A process planning system with feature based neural network search strategy for aluminum extrusion die manufacturing

Aluminum extrusion die manufacturing is a critical task for productive improvement and increasing potential of competition in aluminum extrusion industry. It causes to meet the efficiency not only consistent quality but also time and production cost reduction. Die manufacturing consists first of die design and process planning in order to make a die for extruding the customer's requirement products. The efficiency of die design and process planning are based on the knowledge and experience of die design and die manufacturer experts. This knowledge has been formulated into a computer system called the knowledge-based system. It can be reused to support a new die design and process planning. Such knowledge can be extracted directly from die geometry which is composed of die features. These features are stored in die feature library to be prepared for producing a new die manufacturing. Die geometry is defined according to the characteristics of the profile so we can reuse die features from the previous similar profile design cases. This paper presents the CaseXpert Process Planning System for die manufacturing based on feature based neural network technique. Die manufacturing cases in the case library would be retrieved with searching and learning method by neural network for reusing or revising it to build a die design and process planning when a new case is similar with the previous die manufacturing cases. The results of the system are dies design and machining process. The system has been successfully tested, it has been proved that the system can reduce planning time and respond high consistent plans

Defect Modeling and Vibration-Based Bending Fatigue of Additively Manufactured Inconel 718

Additive manufacturing (AM) is convenient for building components with complex features. However, the long-term integrity of these components is uncertain, since AM parts have defects such as pores and rough surfaces. In this work, an analytical model was developed to determine the impact of defects, and a novel bending fatigue test was used to determine the fatigue life of channeled specimens. The analytical model, based off the theory of critical distances, investigates coupled pores and predicts their potential for fatigue failure. This resulted in a maximum allowable pore size and spacing recommendation for coupled defects. Additionally, specimens with through channels built using laser powder bed fusion were tested in high-cycle vibration-based bending fatigue. The resultant S-N curve and fractography studies revealed similar performance between the channeled specimens and the solid specimens. This research serves to increase understanding of additive defects and their influence on the fatigue life of AM components