Gas Metal Arc Welding (GMAW) Process Optimization of 1.5 mm Uncoated Dual Phase 780 (DP780) Joint for Automotive Body Structural Applications

Author(s):  
Ramakrishna Koganti ◽  
Cindy Jiang ◽  
Chris Karas

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to heat-affected zone (HAZ) at the weld joint. In this study Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 1.5 mm uncoated DP780 to itself was investigated. The objective of the study was to understand the wire feed rate (WFR) and torch (or robot) speed (TS) influence on lap joint tensile strength (static and fatigue). A two factor, two level, full factorial design of experiment (DOE) was conducted to understand the wire feed and torch speed influence on tensile and fatigue strength of the welded joints. In order to understand the curvature effect, center point was also considered in the experiment. Based on the statistical analysis both factors are significant on static tensile strength and two way interaction between wire feed rate and torch speed was also significant on static tensile strength. Wire feed rate was the common significant factor on all three fatigue load conditions (1200 lbf, 1500 lbf and 1900 lbf). Metallurgical properties of the lap joints were evaluated using optical microscopy. Significant hardness drop of 25% was observed at the HAZ. To understand the influence of weld parameters and weld geometry on mechanical properties, correlation analysis was conducted among weld heat input parameters, weld geometry and mechanical properties (both static and fatigue loads).

Author(s):  
Ramakrishna Koganti ◽  
Cindy Jiang ◽  
Chris Karas

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to Heat affected Zones (HAZ) at the weld joint. In this study Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 1.5 mm Electro Galvanized (EG) Transformation Induced Plasticity 780 (TRIP780) to itself was investigated. The objective of the study was to understand the wire feed rate and torch speed influence on lap joint strength. Design of Experiments (DOE) was conducted to understand the wire feed and torch speed influence on tensile strength. Based on the statistical analysis, wire feed rate and torch speed were significant factors on static tensile strength. Two way interaction effect between wire feed and torch speed was significant. Metallurgical properties of the lap joints were evaluated using optical microscopy. No significant drop in hardness at HAZ, however, significant hardening was observed at the base metal and weld fillet interface.


Author(s):  
Ramakrishna Koganti ◽  
Adrian Elliott ◽  
Cindy Jiang

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to heat-affected zone (HAZ) at the weld joint. In this study Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 1.4 mm uncoated DP980 to itself was investigated. The objective of the study was to understand the wire feed rate and torch speed influence on lap joint tensile strength (static and fatigue). A two factor, two level, full factorial design of experiment (DOE) was conducted to understand the wire feed and torch speed influence on tensile and fatigue strength of the welded joints. In order to understand the curvature effect, a center point was also included in the experiment. Based on the statistical analysis, neither factor was significant on static tensile strength, however, a two way interaction between wire feed rate and torch speed was significant on static tensile strength. Metallurgical properties of the lap joints were evaluated using optical microscopy. A significant hardness drop of 40% was observed at the HAZ.


Author(s):  
Ramakrishna Koganti ◽  
Adrian Elliott

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to heat affected zones (HAZ) at the weld joint. In this study, Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 2.0 mm uncoated boron steel and 1.0 mm Usibor® 1500 steel was investigated. The objective of the study was to understand the wire feed rate (WFR) and torch (or robot) travel speed (TTS) influence on lap joint tensile strength. Design of Experiments (DOE) methodology was used to understand the process parameter influence on the joint strength. Based on the statistical analysis, wire feed rate and torch travel speed were significant factors on static tensile strength. The interaction effect between wire feed rate and torch travel speed was not significant. Metallurgical properties of the lap joints were evaluated using optical microscopy. Significant drops in hardness at the HAZ were observed on both Usibor® 1500 P and boron steels.


Author(s):  
Ramakrishna Koganti ◽  
Sergio Angotti ◽  
Armando Joaquin ◽  
Cindy Ziang ◽  
Chris Karas

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to Heat affected Zones (HAZ) at the weld joint. In this study Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 1.5 mm uncoated DP600 to itself was investigated. The objective of the study was to understand the wire feed rate and torch speed influence on lap joint strength. A two factor, two level, full factorial design of experiment (DOE) was conducted to understand the wire feed and torch speed influence on tensile strength. In order to understand the curvature effect, center point was also considered in the experiment. Based on the statistical analysis, wire feed rate was the only significant factor on static tensile strength. Metallurgical properties of the lap joints were evaluated using optical microscopy. Significant hardness drop of 40% was observed at the HAZ.


2016 ◽  
Vol 705 ◽  
pp. 250-254 ◽  
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
M. Wirawan Pu ◽  
Fandi Alfarizi

The aimed of this research is to determine the feasibility and effect of the mixture of the shielding gas in the physical and mechanical properties. Low carbon steel LR grade A in a thickness 12 mm were joined in butt joint types using GMAW (Gas Metal Arc Welding) with groove’s gap 5 mm and groove angle’s 400 with variation of shielding gas composition. The composition of shielding gas that used were 100% Ar, 100 % CO2 and 50% Ar + 50 % CO2. The measured of mechanical properties with regard to strength, hardness and toughness using, tensile test, bending test, Vickers hardness Test, and Charpy impact test respectively. The physical properties examined with optical microscope. Results show that tensile strength of welding metals are higher than raw materials. Welds metal with mixing Ar + CO shielding gas has the highest tensile strength. Hardness of weld metals with the shielding gas 100% Ar, 100 % CO2 and 50% Ar + 50 % CO2 are 244.9; 209.4; and 209.4 VHN respectively. The temperature of Charpy test was varied to find the transition temperature of the materials. The temperature that used were –60°C, -40°C, -20°C, 0°C, 20°C , and room temperature. Weld metals with various shielding gas have similar trends of toughness flux that was corellated with the microstructure of weld .


2010 ◽  
Vol 654-656 ◽  
pp. 2560-2563 ◽  
Author(s):  
Kalenda Mutombo ◽  
Madeleine du Toit

Semi-automatic and automatic pulsed gas metal arc welding (GMAW) of aluminium alloy 5083 with ER5356 filler wire causes considerable softening in the weld. The tensile strength of dressed automatic welds approaches that of the base metal, but the stress concentration caused by the weld toe in undressed semi-automatic welds reduced the tensile strength significantly. Fully automatic welds displayed improved fatigue properties compared to semi-automatic welds.


Author(s):  
R Duraisamy ◽  
S Mohan Kumar ◽  
A Rajesh Kannan ◽  
N Siva Shanmugam ◽  
K Sankaranarayanasamy

The steel wall measuring 120 mm in length and 210 mm in height was manufactured by wire and arc additive manufacturing (WAAM) using ER347 wire and gas metal arc welding (GMAW). The mechanical integrity and microstructure of the WAAM treated plate were examined. It was found that the steel plate was well formed, no clear boundaries between the layers were observed, and different thermal history leads to a variety of microstructures. The hardness of the WAAM-processed plate gradually varied from top to bottom and was between 203.5 HV and 248.2 HV. Microstructure of WAAM 347 consists of columnar dendrites and equiaxed dendrite in the multilayer deposition. The percent volume fraction of delta ferrite in the as-deposited WAAM plate was 4.2 and the predicted ferrite number from WRC-1992 diagram is 4.1. The mechanical properties of the welded parts were anisotropic; the sample at 45° orientation has a higher tensile strength compared to 0° and 90° orientation samples. The fractured tensile specimens in the as-deposited state were characterized by dimple-like structures revealing the ductile fracture. SEM line mapping confirms the presence of intermetallic compounds (NbC) in the WAAM 347 plate.


2018 ◽  
Vol 204 ◽  
pp. 06010
Author(s):  
Taufik Hardiansyah ◽  
Moch Rofi Imron ◽  
Johan Handoko ◽  
Solichin ◽  
Abdul Qolik

The purpose of this study was to find out the tensile strength of GMAW welded carbon steel with electric current variation and wire feed rate. The research method used was experimental research with electric current variation of 120 A, 140 A, and 160 A and variation of wire feed rate 4 m/min and 5 m/min. The tensile strength test of sample was done by ASTM E8 / E8M-09 test standard. The result showed that the electric current variation and wire feed rate in welding of carbon steel with GMAW welding gave effect on the value of tensile strength which was varied. The electric current of 120 A and the wire feed rate of 4 m/min obtained the highest tensile strength of 52.67 kgf/mm2 and welding with electric current of 120 A and wire feed rate of 5 m/min obtained the lowest tensile strength of 48.33 kgf/mm2.


2011 ◽  
Vol 341-342 ◽  
pp. 11-15
Author(s):  
Prachya Peasura ◽  
Mongkol Chaisri

The experimental observation reveals that the influence of gas metal arc welding process on physical properties. The specimen was carbon steel ss400 grade sheet of 6 mm. The experiments with 23 factorial design. The factors used in this study are voltage at 20 and 23 V, travel speed at 5 and 7 mm/sec and wire feed rate were set at 80 and 110 mm/sec. The welded specimens were tested by penetration, width of weld metal and high of weld metal. The result showed that the voltage, travel speed and wire feed rate had interaction on penetration, width of weld metal and high of weld metal at 95% confidential (P value < 0.05). Factors affecting the penetration are the most voltage of 23 V, travel speed 7 mm/sec and wire feed rate 110 mm/sec. were penetration of 31.68 mm. The width of weld metal was most at 9.9 mm. on voltage of 23 V, travel speed 5 mm/sec and wire feed rate 110 mm/sec. The factors affecting the high of weld metal are most voltage of 20 V, travel speed 5 mm/sec and wire feed rate 110 mm/sec. were penetration of 4.51 mm. This research can bring information to the foundation in choosing the appropriate parameters to gas metal arc welding process.


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