Pengaruh VariasiArus dan Posisi Pengelasan SMAW terhadap Sifat Mekanik Baja ST 37

The purpose of this study was to determine the difference in the value of tensile strength, impact and microstructure test results on ST 37 steel plates due to variations in current strength of 80 A, 85 A and 90 A and 1G, 2G and 3G welding positions. The results of this study show the value of Max.load, current strength of 80 A 3G welding position gets the highest value of 5650 kgf, value of Tinsile strength, current strength of 80 A 3G welding position gets the highest value of 44.78 (kgf/mm2), then the strain value, the current strength of 80 A for the 3G welding position gets the highest value of 0.9% and the value of the modulus of elasticity, the current strength of 80 A for the 3G welding position gets the highest value of 97.94 (GPa,KN/mm2), In the value of the impact test results, the current strength of 80 A is the 1G welding position that gets the highest value, which is 116 Joules. In the observation of microstructure testing, 3 points were carried out, Weld metal, HAZ and Base metal at each strong current

Experimental Study on Bead on Plate (BOP) Welding of 6 mm Thick 9% Nickel Steel by Fiber Laser Welding

Nine percent nickel steel has excellent properties in a cryogenic environment, so it has recently been used as a tank material for most LNG fuel-powered ships. However, 9% nickel steel causes arc deflection due to its tendency of magnetization during manual FCAW welding and the currently used filler metal is 10–25 times more expensive as a base metal compared to other materials, depending on manufacturers. Furthermore, the properties of its filler metal cause limitation in the welding position. To overcome these disadvantages, in this study, the tendency of penetration shape was analyzed through a fiber laser Bead on Plate (BOP) welding for 9% nickel steel with a thickness of 6 mm and a range of welding conditions for 1-pass laser butt welding of 6 mm thick 9% nickel steel with I-Groove were derived. Through this study, basic data capable of deriving optimal conditions for laser butt welding of 9% nickel steel with a thickness of 6 mm were obtained.

Recognition of Manual Welding Positions from Depth Hole Image Remotely Sensed by RGB-D Camera

The proportion of welding work in total man-hours required for shipbuilding processes has been perceived to be significant, and welding man-hours are greatly affected by working posture. Continuous research has been conducted to identify the posture in welding by utilizing the relationship between man-hours and working posture. However, the results that reflect the effect of the welding posture on man-hours are not available. Although studies on posture recognition based on depth image analysis are being positively reviewed, welding operation has difficulties in image interpretation because an external obstacle caused by arcs exists. Therefore, any obstacle element must be removed in advance. This study proposes a method to acquire work postures using a low-cost RGB-D camera and recognize the welding position through image analysis. It removes obstacles that appear as depth holes in the depth image and restores the removed part to the desired state. The welder’s body joints are extracted, and a convolution neural network is used to determine the corresponding welding position. The restored image showed significantly improved recognition accuracy. The proposed method acquires, analyzes, and automates the recognition of welding positions in real-time. It can be applied to all areas where image interpretation is difficult due to obstacles.

Analysis of Welding Position and Current on Mechanical Properties of A36 Steel using Shield Metal Arc Welding

Welding is an assembly process that is most often used in the world of construction today. Welding is often used for repairing and maintenance of all tools made of metal, both as a process for filling cracks, temporary joining, or cutting metal parts. This study aims to determine the effect of welding current and position on the tensile strength and Vickers hardness (HV). This study uses ASTM A36 steel plate as base material. The variation of welding currents used are 90A, 110A, and 130A combine with variations in positions 1G, 2G, and 3G. The electrode used in this study is E6013 electrode with a diameter of 3.2 with a butt joint connection. All of processes are performed in room temperature with a strict condition. The results are as follow, the highest Ultimate Tensile Strength is obtained at 90A current and 3G position with a value of 471.93 MPa. For the highest hardness in the Vickers test, it is also obtained at 90A current and 3G position with a value of 242.20 Kgf/mm2.

EVALUATION OF WORK POSITION USING SUBYECTIVITY APPROACH BASED ON RULA METHOD

Workers' activities basically have a positive and negative impact, one of which is the result of a disturbed skeletal and muscular system, which is a decrease in the strength level of body parts which constitutes work productivity when carrying out daily activities. Knowing the danger level of body posture carried out by the welding position, so that it can be given useful input for the company's progress. The method used is the Rapid User Limb Assessment (RULA) method carried out on welding workers and the research method quantitatively and qualitatively then carried out statistical analysis, subjectivity and rula. The results showed that the final score of the posture of squatting, sitting and sitting in a chair had a score of 7, which means a high level of risk and needs immediate improvement. After evaluating the welding position improvement, there is a seat posture with a score of 3 which is a low risk level and requires changes. Same with the welding position sitting on the chair. The squat welding position with a score of 4 which is a low level risk level and sitting work posture has a score of 4 which means a low risk level, but requires a change for the future. From this study it was found that the relationship between Nordic Body Map and RULA was a continuity in squat work postures, which was found that this work posture had the highest risk of danger. Need to improve work posture in certain welding positions in this project or provide counseling about the dangers of work in the work posture if it continues

Pengaruh Variasi Arus pada Pengelasan Baja ST37 Menggunakan Las Shield Metal Arc Welding (SMAW) dengan Posisi Pengelasan 3F

Welding is a very important part in the development and growth of the industry because it has a role in engineering, repair and construction. Shielded metal arc welding (SMAW) is the process of joining two or more materials using a wrapped electrode as heat energy to melt the material. The purpose of this study was to determine the effect and welding defects that arise with current variations so that the optimal welding results obtained from 3 amperes were tested using E6013 electrode diameter 3,2 at the 3F welding position fillet joint. This study uses an experimental method with the material used is St 37 steel with a current variation of 90A, 100A, and 110A. From the research conducted, it was not found optimal welding results where from each ampere tested there was still a weld defect. The defects that occur in the three amperes are caused by the arc, electrode angle, and arc length that exceed the normal limit and are also influenced by the welding speed. From the three variations of the amperage used, the dominant welding results did not occur, namely the 90 amperage, while the 100 amperage welding leg showed good results.

IDENTIFIKASI CACAT LASAN FCAW PADA FONDASI MESIN KAPAL MENGGUNAKAN METODE ULTRASONIC TESTING

Ultrasonic testing is one of the non-destructive inspection methods for welding results. The ultrasonic testing method has several advantages, namely it can be used to analyze the position of the defect in the object, both the depth of the defect and the dimensions of the defect, and it is an environmentally friendly method. Physical defects that are in solid objects of course cannot be known from direct vision so it is necessary to carry out an inspection of an object to see whether or not there are defects that occur in solid objects. Ultrasonic testing of the results of FCAW welding on the foundation of the ship's engine. FCAW welding is applied to the foundation with two types of welding positions, namely the overhead position coded P1 and the horizontal position coded P2. The test was carried out using a wave frequency of 4 MHz and using a 0° probe for analysis of defects in the area around the weld metal and a 70° probe for analysis of the weld metal. The tests were carried out using the ASME section V and ASTM E164 standards as the standard for determining defects. The test results at the P1 welding position found two types of defects, namely incomplete fusion defects with five welding points with the longest defect length of 40mm and porosity defects with two points with the longest defect length of 30mm. While the results of ultrasonic testing at the P2 welding position found two types of defects, namely slag inclusion defects with a defect length of 35mm and incomplete penetration defects with a defect length of 20 mm. The conclusion of ultrasonic testing is that the difference in welding positions is that the welding position greatly affects the quality of the welding results. The defects resulting from the welding position also vary.