Artificial neural networks (ANN) were used to model the strength, ductility and hardness of multi-pass welds deposited by gas tungsten arc welding (GTAW) in plates of commercial titanium alloys. The input parameters o...Artificial neural networks (ANN) were used to model the strength, ductility and hardness of multi-pass welds deposited by gas tungsten arc welding (GTAW) in plates of commercial titanium alloys. The input parameters of the ANN are the alloy composition and heat treatment conditions and its output is one of the mechanical properties of the weld metal of titanium alloys, namely ultimate tensile strength (UTS), yield strength, elongation, reduction of the area (ROA) and hardness. The titanium alloys used in the work include commercially pure titanium, alpha or near-alpha titanium, alpha-beta titanium and beta or near-beta titanium.展开更多
The dissimilar metal weld is demanding as well as the similar weld, however, dissimilar weld is more complex than similar weld due to the necessity of being applied in zones where a requirement is to improve some prop...The dissimilar metal weld is demanding as well as the similar weld, however, dissimilar weld is more complex than similar weld due to the necessity of being applied in zones where a requirement is to improve some properties. In this work the main purpose is to know the mechanical behavior of a dissimilar weld between HSLA Steel and Superduplex Stainless Steel (SDSS) to establish if the joint is feasible or not. The alloys were welded with GTAW process using a 60-deg and 90-deg single-V groove test specimens in order to observe the effect of the weld pass. The filler metal was chosen with the aid of Schaeffler diagram. It was found that the ER 25.10.4L filler metal provided the best equilibrium between ferrite and austenite phase in the Superduplex Stainless Steel final microstructure and a band of martensite in the HSLA steel final microstructure. The dissimilar joint presented acceptable mechanical properties which are superior to the HSLA in the as-received condition, but lower than the SDSS in the as-received condition, proving that the filler metal was the adequate.展开更多
This paper analyses the performance request of arc welding power source used in intelligent control of weld pool shape in pulsed GTAW, and develops a sample power source. The main circuit of the power source takes the...This paper analyses the performance request of arc welding power source used in intelligent control of weld pool shape in pulsed GTAW, and develops a sample power source. The main circuit of the power source takes the structure of single ended inverter with two switches, and takes IGBTs as power switches. The working frequency of the inverter is set at 20 kHz. The control circuit takes PWM circuit as center, and uses single chip computer to complete the manage functions such as the control of working sequence, setting and changing of the welding parameters, sensing of the welding states and communication with outside computer etc. The dynamic reacting time of the whole power is 1 ms, the range of the output current is 5～250 A, the precision of the output current reaches to 1 A. The power strikes arc by contacting workpiece under 5 A, and have convenient interface with system computer. All above shows this power source is one with high performance.展开更多
文摘Artificial neural networks (ANN) were used to model the strength, ductility and hardness of multi-pass welds deposited by gas tungsten arc welding (GTAW) in plates of commercial titanium alloys. The input parameters of the ANN are the alloy composition and heat treatment conditions and its output is one of the mechanical properties of the weld metal of titanium alloys, namely ultimate tensile strength (UTS), yield strength, elongation, reduction of the area (ROA) and hardness. The titanium alloys used in the work include commercially pure titanium, alpha or near-alpha titanium, alpha-beta titanium and beta or near-beta titanium.
文摘The dissimilar metal weld is demanding as well as the similar weld, however, dissimilar weld is more complex than similar weld due to the necessity of being applied in zones where a requirement is to improve some properties. In this work the main purpose is to know the mechanical behavior of a dissimilar weld between HSLA Steel and Superduplex Stainless Steel (SDSS) to establish if the joint is feasible or not. The alloys were welded with GTAW process using a 60-deg and 90-deg single-V groove test specimens in order to observe the effect of the weld pass. The filler metal was chosen with the aid of Schaeffler diagram. It was found that the ER 25.10.4L filler metal provided the best equilibrium between ferrite and austenite phase in the Superduplex Stainless Steel final microstructure and a band of martensite in the HSLA steel final microstructure. The dissimilar joint presented acceptable mechanical properties which are superior to the HSLA in the as-received condition, but lower than the SDSS in the as-received condition, proving that the filler metal was the adequate.
文摘This paper analyses the performance request of arc welding power source used in intelligent control of weld pool shape in pulsed GTAW, and develops a sample power source. The main circuit of the power source takes the structure of single ended inverter with two switches, and takes IGBTs as power switches. The working frequency of the inverter is set at 20 kHz. The control circuit takes PWM circuit as center, and uses single chip computer to complete the manage functions such as the control of working sequence, setting and changing of the welding parameters, sensing of the welding states and communication with outside computer etc. The dynamic reacting time of the whole power is 1 ms, the range of the output current is 5～250 A, the precision of the output current reaches to 1 A. The power strikes arc by contacting workpiece under 5 A, and have convenient interface with system computer. All above shows this power source is one with high performance.
