Predictive Control for Manual Plasma Arc Pipe Welding

Author(s):  
Xiangrong Li ◽  
YuMing Zhang

Plasma arc welding (PAW) has several advantages over traditional gas tungsten arc welding (GTAW) process. However, due to its sensitivity to welding parameters, this process has not been widely used in industry, especially for manual welding applications where variations in welding parameters are substantial. This paper introduces and implements a model predictive control (MPC) method to adjust welding current in order to compensate the effects from these variations during manual plasma welding operation. A linear model with adequate accuracy has been selected for the design of control system. Closed-loop control experiments verified the effectiveness of developed control system.

Author(s):  
Italo do Valle Tomaz ◽  
Fernando Henrique Gruber Colaço ◽  
Shoaib Sarfraz ◽  
Danil Yu. Pimenov ◽  
Munish Kumar Gupta ◽  
...  

AbstractGas tungsten arc welding (GTAW) technology is widely used in industry and has advantages, including high precision, excellent welding quality, and low equipment cost. However, the inclusion of a large number of process parameters hinders its application on a wider scale. Therefore, there is a need to implement the prediction and optimization models that effectively enhance the process performance of the GTAW process in different applications. In this study, a five-factor five-level central composite design (CCD) matrix was used to conduct GTAW experiments. AISI 1020 steel blank was used as a substrate; UTP AF Ledurit 60 and UTP AF Ledurit 68 were used as the materials of two tubular wires. Further, an artificial neural network (ANN) was used to simulate the GTAW process and then combined with a genetic algorithm (GA) to determine welding parameters that can provide an optimal weld. In welding experiments, five different welding current levels, welding speed, distance to the nozzle, angle of movement, and frequency of the wire feed pulses were used. Using GA, optimal welding parameters were determined: welding current = 222 A, welding speed = 25 cm/min, nozzle deflection distance = 8 mm, travel angle = 25°, wire feed pulse frequency = 8 Hz. The determination coefficient (R2) and RMSE value of all response parameters are satisfactory, and the R2 of all the data remained higher than 0.65.


2013 ◽  
Vol 711 ◽  
pp. 183-187 ◽  
Author(s):  
Prachya Peasura

This research was to study of gas tungsten arc welding (GTAW) welding parameters that affects to the mechanical properties of aluminum alloy AA5083 welding with GTAW. The full factorial design was experiment. The factors was study in type of polarity on alternating current (AC), direct current electrode negative (DCEN) and direct current electrode positive (DCEP), levels of welding current for 180,200,220 and 240 amp. The specimen to analyses the physical properties has microstructure and hardness of weld metal and heat affected zone. The result showed that type of welding current and levels of welding current interaction hardness at the level of confidence 95% (P-value<0.05). The factor hardness maximum of weld metal was alternating current at level of current 240 amp. and hardness of 136.53 HV. The factor hardness maximum of HAZ value was alternating current at level of welding 220 amp. and hardness of 169.43 HV. The welding parameters can result in increasing Mg2Si intensity in parent phase. It can also be observed that Mg2Si at the parent phase decreased due to high welding current in HAZ.This research can be used as information in choosing how to welding parameter for gas tungsten arc welding of aluminum alloy.


2013 ◽  
Vol 651 ◽  
pp. 355-360 ◽  
Author(s):  
Yi Jiang ◽  
Ming Liu ◽  
Yao Hui Lu ◽  
Bin Shi Xu

Variable polarity plasma arc welding has been widely used to manufacture industries. The effects of welding current and plasma gas flow as the most important parameters on variable polarity plasma arc pressure were discussed experimentally. To welding current, two experimental were designed to discuss the effects of straight polarity current and reversed polarity current on arc pressure respectively. It could be concluded that arc pressure is quadratic with welding current. To plasma gas flow, both experimental and numerical analysis are used to discuss the mechanisms of plasma gas flow to arc pressure, and it could be conclude that arc pressure is quadratic with plasma gas flow rather than linear.


2012 ◽  
Vol 246-247 ◽  
pp. 707-711
Author(s):  
Prachya Peasura

ASTM A36 carbon steel is the most commonly available of the hot-rolled steels. This specification covers carbon steel shapes, plates, and bars of structural quality for use in riveted, bolted, or welded construction of bridges and buildings, and for general structural purposes. The research was to study the in effected of gas tungsten arc welding parameters which effects the hardness and physical characteristics of welding for carbon steel ASTM A36. The specimen was carbon steel sheet metal 6 mm thick. The 23 factors experiment was used polarity direct current electrode negative (DCEN) and alternating current (AC), welding current at 90 and100 amperes with tungsten electrode angles at 30 and 60degree. The weld sample was test by hardness and penetration. The result showed that polarity, welding current and tungsten electrode angle had on interaction on hardness and penetration at 95% confidence (p-value < 0.05).The factors made maximum hardness was polarity AC, welding current 100 amp. and tungsten angle 60๐of 803.16 HV. The factors made maximum penetration was polarity DCEN, welding current 100 amp. and tungsten angle 60๐ of 2.71mm. The research data can be used to determine the appropriate gas tungsten arc welding process of carbon steel weld.


2014 ◽  
Vol 536-537 ◽  
pp. 309-313
Author(s):  
Wen Jian Ren ◽  
Xin Feng Liu ◽  
Jin Qiang Gao

An observation system is developed with three ordinary industrial CCD cameras to capture the images of the weld pool and the keyhole. Experiments are conducted to evaluate the affecting relationship between welding parameters (welding current and welding speed) and the size of weld pool and keyhole. The observation results lay foundation to understand the weld pool and the keyhole behavior in PAW process and to design the future control system.


Kapal ◽  
2020 ◽  
Vol 17 (3) ◽  
pp. 107-113
Author(s):  
Tarmizi Tarmizi ◽  
Kevin Daniel Sianturi ◽  
Irfan Irfan

Aluminum 6061 is an aluminum alloy that is widely used in various industrial fields, which heat treatable. However, it can be joined using a welding process. Aluminum joining using the Gas Tungsten Arc Welding (GTAW) process has become the option to produce good quality joints. This research aims to get optimum welding parameters by knowing the mechanical properties and microstructure of the welding results. The GTAW process uses a 25-volt voltage, Argon protective gas flow rate of 15 liters per minute with filler rod ER 5356 with 2.4 mm diameter and electrodes tungsten 2.4 mm in diameter. This process uses a single V butt joint and groove angle of 60° with variations in the current of 100, 110 and 120 A. The results indicate that specimens with a variety of current of 110 A give better results in the absence of defects, have a tensile strength of 152 MPa, and get a hardness value of 87.55 HV, which is the highest compared to the other two specimens. Whereas specimens with the current variation of 100 and 120 A have defects in the weld area. The optimum parameters of the 6061 aluminum GTAW process with a thickness of 6 mm using a current of 110 A bring on better outcomes and mechanical properties than the use of currents of 100 and 120 A.


Author(s):  
Rishi Pamnani ◽  
M Vasudevan ◽  
P Vasantharaja ◽  
T Jayakumar

DMR249A steel is indigenously developed high strength low alloy (HSLA) steel. The steel is being used for construction of Indian Aircraft Carrier and other new ships under construction at various ship yards in India. In order to enhance the depth of penetration (DOP) achievable in a single pass for gas tungsten arc welding (GTAW) process, activated fluxes were developed for the steel. The process is called activated flux gas tungsten arc welding (A-GTAW). Design of experiments (DOE) approach was employed using response surface methodology (RSM) and Taguchi technique to optimize the welding parameters for achieving maximum DOP in a single pass. Design matrix was generated using DOE techniques and bead on plate experiments were carried out to generate data for influence of welding process variables on DOP. The input variables considered were current, torch speed, and arc gap. The DOP was considered as response variable. The equations correlating DOP with the process parameters were developed for both the optimization techniques. The identified optimum process parameters were validated by carrying out bead on plate experiments. The RMS error of the predicted and measured DOP values for the validation experiments of the RSM (D-optimal) and Taguchi optimization technique was found to be 0.575 and 0.860, respectively. Thus, RSM (D-optimal) was observed to predict optimized welding process parameters for achieving maximum DOP with better accuracy during A-GTAW process.


2021 ◽  
Vol 43 (1) ◽  
pp. 17
Author(s):  
Apang Djafar Shiedieque ◽  
Amri Abdulah ◽  
Dede Ardi Rajab ◽  
Jefri Jafarudin

AbstrakTeknologi pengelasan adalah metode penyambungan material yang umum digunakan di industri, konstruksi, dan manufaktur. Makalah ini membahas Gas Tungsten Arc Welding (GTAW) menggunakan logam pengisi ER308 untuk menyambung logam dasar A304. Penelitian ini bertujuan untuk menguji kekuatan tarik dan  lentur dari bahan dengan variasi tipe v-groove dan arus pengelasan sebagai parameter pengelasan. Jenis sambungan yaitu butt-welds dengan 45° v-groove, 60° v-groove, dan 60 ° double v-grooves, sedangkan arus pengelasan bervariasi antara 75A, 100A dan 125A. Uji kuat tarik menggunakan HUNG TA-520 dengan kapasitas mesin 500 kN. Hasil kekuatan puncak masing-masing capaian berada pada 645,70 N / mm2, 633,16 N / mm2, dan 613,89 N / mm2. Kemudian pada hasil uji tekuk retakan terbesar pada sampel terjadi pada arus 75A. Dari hasil ini lebih baik menggunakan arus 100A. AbstractWelding technology is a method of joining materials commonly used in industry, construction, and manufacturing. This paper discusses Gas Tungsten Arc Welding (GTAW) using ER308 filler metal to join the A304 base metal. This study aims to examine the strength and bending test of the variation of the v-groove type and welding current as welding parameters. Types of joints are butt-welds with 45 ° v-grooves, 60 ° v-grooves, and 60 ° double v-grooves, while the welding current varies between 75A, 100A, and 125A. Tensile strength test using HUNG TA-520 with an engine capacity of 500 kN. The peak strength results of each achievement are at 645.70 N / mm2, 633.16 N / mm2, and 613.89 N / mm2. Then the bending test results, the largest cracks in the sample, occurred at a current of 75A. From these results it is better to use a current of 100A.


2015 ◽  
Vol 15 (4) ◽  
pp. 65-68 ◽  
Author(s):  
E. Przełożyńska ◽  
K.N. Braszczyńska-Malika ◽  
M. Mróz

Abstract The gas-tungsten arc (GTA) welding behaviors of a magnesium matrix composite reinforced with SiC particles were examined in terms of microstructure characteristics and process efficiencies. This study focused on the effects of the GTAW process parameters (like welding current in the range of 100/200 A) on the size of the fusion zone (FZ). The analyses revealed the strong influence of the GTA welding process on the width and depth of the fusion zone and also on the refinement of the microstructure in the fusion zone. Additionally, the results of dendrite arm size (DAS) measurements were presented.


2020 ◽  
Vol 26 (4) ◽  
pp. 426-431
Author(s):  
Wei LI ◽  
Gaochong LV ◽  
Qiang WANG ◽  
Songtao HUANG

To resolve the problem of grain coarsening occurring in the fusion zone and the heat-affected zone during conventional gas tungsten arc welding(C-GTAW) welded titanium alloy, which severely restricts the improvement of weld mechanical properties, welding experiments on Ti-6Al-4V titanium alloy by adopting ultra-high frequency pulse gas tungsten arc welding (UHFP-GTAW) technique were carried out to study arc characteristics and weld bead microstructure. Combined with image processing technique, arc shapes during welding process were observed by high-speed camera. Meanwhile the average arc pressure under various welding parameters were obtained by adopting pressure measuring equipment with high-precision. In addition, the metallographic samples of the weld cross section were prepared for observing weld bead geometry and microstructure of the fusion zone. The experimental results show that, compared with C-GTAW, UHFP-GTAW process provides larger arc energy density and higher proportion of arc core region to the whole arc area. Moreover, UHFP-GTAW process has the obviously effect on grain refinement, which can decrease the grain size of the fusion zone. The results also revealed that a significant increase of arc pressure while increasing pulse frequency of UHFP-GTAW, which could improve the depth-to-width ratio of weld beads.


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