Analysis of repetitive repair welding on properties on stainless steel to carbon steel dissimilar metal joints

Repair welding of dissimilar material is frequently used in steel structures to replace the weldment defect and prolong the material service life. Generally, repair welding is a crucial topic that needs more discussion due to the lack of application in real industry. In order to reduce cost and dependence on the high skilled welders, repair welding on dissimilar pipe materials Stainless Steel 304 (AISI 304) and Carbon steel 1387 (BS 1387) were performed using Gas Metal Arc Welding (GMAW) with 100 mm each long. Furthermore, dissimilar is not just the material but also the diameter of the pipes. Fixed nozzle rotational jig was used as the main welding equipment with current (A), voltage (V) and rotational speed (rpm) as the main parameter. The study was focused on the effect of repair welding on mechanical properties, microstructure formation of AISI 304 and BS 1387 and prediction of service life of the dissimilar material repaire welded pipes. Tensile, microhardness, and fatigue tests were performed with nine runs of samples with three times of repetition as a planning matrix generated by Minitab Software. Design of Experiment (DOE) was used to plan the whole project using Taguchi Method as the main platform. Prediction of tensile testing and fatigue testing failure location was performed using ANSYS software. The outcome of the study shows that repair welding affected the performance of weldment, especially on mechanical properties. Tensile and microhardness testing showed the highest value on the second repair, while fatigue testing on the third repair. The heat generated during the welding process also affects the Heat Affected Zone (HAZ), and the microstructure formation of them was discussed. The regression equation of each repair was generated, and validation error was calculated. Prediction of the pipe service life schedule was performed using an FMEA chart in order to have a proper preventive maintenance schedule

TAGUCHI METHOD PREDICTION OF EDM DIE-SINKING PARAMETERS ON SURFACE INTEGRITY FOR ALUMINIUM COMPOSITE USING COPPER ELECTRODE

This paper investigates the performance of copper electrode on the surface integrity of aluminium alloy LM6 (Al-Sil2) in the electrical discharge machine (EDM) die sinking.The relationship between the machining parameters which is pulse-on time, pulse-off time, peak current and voltage on surface integrity has been investigated. Copper tool of diameter 10mm was chosen as an electrode. Scanning electrone microscope (SEM) was used to observe the microstructure of LM6 after machining process and the average of recast layer (RL). It was found that the current and pulse on time significantly affected the recast layer, while the pulse off time and voltage are the less significant factor that affected the responses. Result shows that increasing the pulse on time, increases the recast layer. Thus, it shows that copper have the capability to cut aluminium alloy LM6 using EDM die sinking

The effect of EDM die-sinking parameters on surface integrity for aluminium composite using copper electrode.

This paper investigates the performance of copper electrode on the surface integrity of aluminium alloy LM6 (Al-Sil2) in the electrical discharge machine (EDM) die sinking.The relationship between the machining parameters which is pulse-on time, pulse-off time, peak current and voltage on surface integrity was study.Copper tool of diameter 10mm was chosen as an electrode. Scanning electrone microscope (SEM) was used to observe the microstructure of LM6 after machining process and the average of recast layer (RL). It is found that the current and pulse on time was significantly affected the recast layer while pulse off time and voltage are less significant factor that affected the responses. Result shows that increasing the pulse duration has increased the recast layer.Thus, it shows that copper having capability to cut aluminium alloy LM

Statistical analysis of second repair welding on dissimilar material using Taguchi method

This paper presents an experimental investigation on effect of welding parameter to repair welding of dissimilar material using Gas Metal Arc Welding (GMAW) machine. Taguchi Method has been used to analyse the statistical analysis by using Minitab Software. Repair welding getting more popular nowadays due to saving cost and prolong the material service life. The effect of repair welding of dissimilar material on mechanical properties have been studied. Statistical analysis using Taguchi Method by Minitab Software with three times repetition of L9 orthogonal array. Setting up GMAW machine with current (150A-170A), voltage (17V-21V) and jig rotational speed (50rpm-100rpm) were prepared with 3.00mm of Stainless Steel 304L and 3.60mm Carbon Steel 1387.Result shows that voltage gave a huge impact to tensile testing and micro hardness of second repair welding. While current and jig rotational speed gave less impact to responses. The benefit shown has caused repair welding to be accepted and applied in the industry. Regular and total maintenance is able to contribute to the savings while producing good preventive maintenance schedule

The Effect of EDM Die-Sinking Parameters on Non-Conductive Materials

The machining ability of electrical discharge machining (EDM) die-sinking on acrylic as non-conductive material was studied. The objective of the study is to establish a new setup to machine a non-conductive material by using EDM die-sinking. Acrylic plastic material was selected as to represent the other groups of non-conductive materials. The experiment was conducted using a discharge sinking machine with copper as the tool electrode. Metal insert as conductive material was plug-in into acrylic workpiece. Polarity of the setup was set to positive at the copper electrode and negative at the plug-in metal insert. The variable input parameters such as electric discharge current, voltage, pulse on time and pulse off time had been observed to review machinibility of die-sinking EDM by taking the overcut and taper of sidewall of holes produced. It was found that the highest current supply during machining, the deepest hole occurred on the acrylic workpiece. Thus, the new method purposed on this study proved that non-conductive material can be machined using the EDM die-sinking

The effect of EDM die-sinking parameters on surface integrity for aluminium composite using copper electrode

This paper investigates the performance of copper electrode on the surface integrity of aluminium alloy LM6 (Al-Sil2) in the electrical discharge machine (EDM) die sinking.The relationship between the machining parameters which is pulse-on time, pulse-off time, peak current and voltage on surface integrity was study.Copper tool of diameter 10mm was chosen as an electrode. Scanning electrone microscope (SEM) was used to observe the microstructure of LM6 after machining process and the average of recast layer (RL). It is found that the current and pulse on time was significantly affected the recast layer while pulse off time and voltage are less significant factor that affected the responses. Result shows that increasing the pulse duration has increased the recast layer.Thus, it shows that copper having capability to cut aluminium alloy LM

The Effect of EDM Die-sinking Parameters on Non-conductive Materials

The machining ability of electrical discharge machining (EDM) die-sinking on acrylic as non-conductive material was studied. The objective of the study is to establish a new setup to machine a non-conductive material by using EDM die-sinking. Acrylic plastic material was selected as to represent the other groups of non-conductive materials. The experiment was conducted using a ischarge sinking machine with copper as the tool electrode. Metal insert as conductive material was plug-in into acrylic workpiece. Polarity of the setup was set to positive at the copper electrode and negative at the plug-in metal insert. The variable input parameters such as electric discharge current, voltage, pulse on time and pulse off time had been observed to review machinibility of diesinking EDM by taking the overcut and taper of sidewall of holes produced. It was found that the highest current supply during machining, the deepest hole occurred on the acrylic workpiece. Thus, the new method purposed on this study proved that non-conductive material can be machined using the EDM die-sinking

The Performance of Brass Electrode on Material Removal for Aluminium Composite in EDM Die-Sinking

This paper investigates the performance of brass electrode on the removal of aluminium alloys LM6 (Al-Sil2) in an electrical discharge machining (EDM) die-sinking. The machining parameters such as pulse-on time, pulse-off time and peak current were selected to find the responses on the material characteristics such as material removal rate (MRR), electrode wear rate (EWR) and surface roughness (Ra). Brass with diameter of 10mm was chosen as an electrode. Orthogonal array of Taguchi method was used to develop experimental matrix and to optimize the MRR, EWR and Ra. It is found that the current is the most significantly affected the MRR, EWR and Ra while pulse on time, pulse off time and voltage are less significant factor that affected the responses. Percentage optimum value of MRR increases to 3.99%, however EWR and Ra reduce to 3.10% and 2.48% respectively. Thus, it shows that brass having capability to cut aluminium alloys LM6

The Effect of EDM Die-sinking Parameters on Material Characteristic for Aluminium Composite Using Tungsten Copper Electrode

The machining ability of electrical discharge machining (EDM) die-sinking on aluminium LM6 (Al-Sil2) as a new material is investigated. The objective of this paper is to determine the relationship between the machining parameters which are pulse-on time, pulse-off time and peak current on the material characteristics such as material removal rate (MRR,electrode wear rate (EWR) and surface roughness (Ra). Tungsten copper tool of diameter 10mm was chosen as an electrode. Design of experiment using Taguchi method was used to develop experimental matrix and optimize the MRR, EWR and Ra. The analysis was done using the Minitab software. It is found that the current and pulse on time are significantly affected the MRR, EWR and Ra while pulse off time and voltage are less significant factor that affected the responses. From the Taguchi method, the best setting of optimum value was obtained. Thus, it shows that Taguchi method is the best quality tools that can be applied for production

The Effect of EDM Die-Sinking Parameters on Material Characteristic for Aluminium Composite Using Tungsten Copper Electrode

The machining ability of electrical discharge machining (EDM) die-sinking on aluminium LM6 (Al-Sil2) as a new material is investigated.The objective of this paper is to determine the relationship between the machining parameters which are pulse-on time, pulse-off time and peak current on the material characteristics such as material removal rate (MRR), electrode wear rate (EWR) and surface roughness (Ra). Tungsten copper tool of diameter 10mm was chosen as an electrode. Design of experiment using Taguchi method was used to develop experimental matrix and optimize the MRR, EWR and Ra. The analysis was done using the Minitab software. It is found that the current and pulse on time are significantly affected the MRR, EWR and Ra while pulse off time and voltage are less significant factor that affected the responses. From the Taguchi method, the best setting of optimum value was obtained. Thus, it shows that Taguchi method is the best quality tools that can be applied for production