Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : DOE


Study of Mechanical Properties of Carbon Steel Plate SA-516 Gr. 70 Welded by SAW Using V-Shape Joint Design

Samir A. Amin; Mohannad Y. Hanna; Abdulaziz S. Khider

Engineering and Technology Journal, 2020, Volume 38, Issue 2, Pages 152-165
DOI: 10.30684/etj.v38i2A.269

Submerged arc welding (SAW) is a fusion type welding and it is considered one of the most important welding types due to its inherent capabilities of high welding speed, high deposition rate, welding large thickness plates owing to its deep penetration characteristic and many other advantages. In this study, the goal was to investigate the effect of welding parameters, namely (welding current and welding speed) as well as the joint design on the mechanical properties (yield stress, bending force on the face of the weldment and hardness of the weld metal. Experiments were conducted employing Design of Expert (DOE) software and Response Surface Methodology (RSM) technique. The experiments were conducted by welding ASME SA-516 Gr. 70 steel plate with dimension (300 mm × 150 mm × 10 mm) depending upon the design matrix developed via the DOE. Results manifested that the optimum process parameters for maximum yield stress, maximum bending force and minimum hardness were at (425 amps) welding current and (35 cm/min) welding speed, where the arc voltage was held constant at (37 volts). The optimum values for the yield stress, bending force and hardness were (474.447 MPa, 36.997 kN and 150 HV), respectively. Finally, it was found that the predicted and experimental results of yield stress, bending force and hardness agree very well according to the ultimate error (1.05%, 1.92%, and 4.25 %), respectively.

Influence of SAW Welding Parameters on Microhardness of Steel A516-Gr60

Sadeq H. Bakhy; Samir A. Amin; Fouad A. Abdullah

Engineering and Technology Journal, 2018, Volume 36, Issue 10A, Pages 1039-1047
DOI: 10.30684/etj.36.10A.4

Submerged Arc Welding (SAW) process is generally used for industries, such as petroleum storage tanks, pressure vessels, and structural components.
Good mechanical properties of welded joint lead to crack-free strong joints. In this research, included angle, current, welding travel speed and arc voltage were utilized as welding parameters to weld ASTM A516 Grade 60 (low carbon steel). The experiments were carried out according to a design matrix that established by DOE (Version10) with RSM technique. Microhardness of welded samples was measured by a Digital Microhardness Tester, and then RSM technique was used to model and optimize the microhardness based on the welding parameters. The results showed that the including angle and welding current have a great effect on the microhardness. The optimum solution for minimum microhardness was found at 450 Amp welding current, 38 cpm welding speed, 34-volt arc voltage and included angle of 60⁰. The optimum value of microhardness was (186.7 HV). Eventually, the experimental and predicted results of microhardness were found in good agreement with 4.6%. maximum error.

Studying the Efficiency of Lime-Soda Sinter Process to Extract Alumina from Colored Kaolinite Ores Using Factorial Technique of Design of Experiments

Hijran Z. Toama; Abdul-Wahab A. Al-Ajeel; Ajheen H. Jumaah

Engineering and Technology Journal, 2018, Volume 36, Issue 5A, Pages 500-508
DOI: 10.30684/etj.36.5A.4

As the increasing demand for alumina in recent years with the result diminishing reserve of bauxite, the need to secure a domestic raw material base is driving research in new technologies to process low grade ores into alumina, with the intention that these technologies will lead to a significant reduction of bauxite and alumina transportation costs, allow the extraction of more valuable components from the ore and reduce environmental impact. Clays are types of the low-grade aluminum ores, they're also well abundant which make them a potential substitutes for Bauxite. In this work, lime soda sinter process was adopted for extracting alumina from kaolinitic claystone from Al-Ga'ara formation (Duekhla) quarry in western Iraq. The operation efficiency of sintering was studied in which the whole process has been done with three stages: the sintering process for the raw materials, leaching and carbonizing processes to precipitate and separate the alumina from the leach pregnant solution . Factorial technique of Design of Experiments (DOE) module in Minitab was used as a principal methodology to examine the sintering efficiency over alumina extraction. The results obtained showed that the optimum parameters for the sintering operation were CaO/SiO2 molar ratio of 2.2, Na2O/Al2O3 molar ratio of 1.2, sintering temperature at 1213 °C for 90 min. The sintered materials were leached with sodium carbonate solution, and sodium aluminate solution was obtained. By bubbling carbon dioxide gas into this extract solution aluminum hydroxide [Al(OH)3] has been precipitated and on calcination at 1200 °C for 2 hrs, alpha alumina (α-Al2O3) was obtained with purity of 98.5 %.

Optimization the Resistance Spot Welding Parameters of Austenitic Stainless Steel and Aluminum Alloy Using Design of Experiment Method

Sabah Khammass Hussein; Osamah Sabah Barrak

Engineering and Technology Journal, 2016, Volume 34, Issue 7, Pages 1383-1401
DOI: 10.30684/etj.34.7A.11

This research aims to study the effect of RSW parameters on the sheerforce of the spot weldedfor two materials {AISI 304L and AA 6061-T6}with (0.5 and 0.7 mm) thickness. Three values for each welding parameters (welding current, electrode force, squeeze time and welding time) are to be used. The effect of those parameters has been analyzed by using design of experiments (DOE) in order to determine and reduce the number of the tested specimens.
The experimental tests have been donethat are;shear, micro hardness tests and microstructure examination. It was found that the maximum shear force in welding of similar material AISI 304L is (F = 4.78 KN for t = 0.7 mm), while in the joint of dissimilar material (AA 6061-T6 with AISI 304L), the maximum shear force is (F = 1.42 KN for t = 0.7 mm). These values have been optimized to reach (F =5.13 KN & F =1.54 KN) respectively by using DOE. The minimum shear force was (F = 0.07 KN in t = 0.5 mm).
It was found that, increasing the welding current and sheet thickness gave an increase in the shear force, but at the same time the reduction in shear force has occurred during the increasing in electrode force, squeeze time and welding time. From micro hardness tests, it was found that the maximum value of hardness was at the center of nugget zone (NZ) and it reduces slightly until reaching constant values away from nugget zone.

Analysis and Optimization of Resistance Spot Welding Parameter of Dissimilar Metals Mild Steel and Aluminum Using Design of Experiment Method

Sabah Khammass Hussein

Engineering and Technology Journal, 2015, Volume 33, Issue 8, Pages 1999-1011

This research aims to study the effect of parameters of the resistance spot welding (RSW) on the shear strength of the spot weld for different metals {AA 6061-T6and AISI 1010}using (0.5 and 0.7 mm) thickness.Three values for each welding parameters (welding current, electrode force, squeeze time and welding time) are to be used. The effect of those parameters have been analyzed by Minitab program by design of experiments (DOE) in order to determine and reduce the number of specimens required to achieve the tests. The design of experiment method which used was Taguchi method
The experimental tests that had been done are shear, Microhardness and microstructure tests.It was found that the maximum shear force in welding of dissimilar metals(AA 6061-T6 with AISI 1010)is (F = 1.14 KN for t = 0.7 mm ).This value has been optimized to reach (F =1.24KN) using DOE. The minimum shear force was(F = 0.25 KN in t = 0.5 mm).
In general, increasing the welding current and sample thickness gave an increase in the shear force, but at the same time the reduction in shear force have occurred during the increasing in electrode force, squeeze time and welding time.From Microhardness tests, the maximum value of hardness is found at the center of nugget zone (NZ) and it reduces slightly until reaching constant values away from NZ.