The Experts below are selected from a list of 186 Experts worldwide ranked by ideXlab platform
Y X Wu - One of the best experts on this subject based on the ideXlab platform.
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effects of preheating temperature on Cold Cracks microstructures and properties of high power laser hybrid welded 10ni3crmov steel
Materials & Design, 2011Co-Authors: L H Hu, Zhigang Li, Jianguo Huang, Y X WuAbstract:Abstract Laser hybrid welding has become one of the most promising welding methods for high strength low alloy steels due to combining the advantage of the laser and arc. A novel Y-groove Cold Cracking test adapted to laser hybrid welding is designed to assess the weldability of 10Ni3CrMoV steels at room temperature and different preheating temperatures. The experimental results show that the orientation of the predominant root Cracks generally follows the contour of the fusion line. As the temperature increases from 25 °C to 150 °C, at first the root Crack rate decreases and then slightly increases at 150 °C. The root Crack rate obtained at 120 °C is the lowest. The fracture model changes from a brittle cleavage fracture to a mixture fracture with quasi-cleavage facets and dimples. The thermal cycle curves of laser hybrid welding obtained by temperature measurement systems are used to evaluate the Crack resistance and microstructure transformation. The microstructures of welded joints obtained at different temperatures are analyzed by optical microscope (OM). The results reveal that the microstructures of the coarse grained region and the fusion zone at 120 °C have higher Cold Crack resistance and good impact toughness. Mechanical properties of the welded joint obtained at 120 °C and 150 °C are comprehensively evaluated by microhardness test, uniaxial tensile test and charpy V-notch impact test with side notches. Fractographs of the impact specimens are studied by scanning electron microscopy (SEM). The test results show that the welded joints obtained at 120 °C have satisfactory mechanical properties that can meet the technical requirements for shipbuilding industry.
L H Hu - One of the best experts on this subject based on the ideXlab platform.
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effects of preheating temperature on Cold Cracks microstructures and properties of high power laser hybrid welded 10ni3crmov steel
Materials & Design, 2011Co-Authors: L H Hu, Zhigang Li, Jianguo Huang, Y X WuAbstract:Abstract Laser hybrid welding has become one of the most promising welding methods for high strength low alloy steels due to combining the advantage of the laser and arc. A novel Y-groove Cold Cracking test adapted to laser hybrid welding is designed to assess the weldability of 10Ni3CrMoV steels at room temperature and different preheating temperatures. The experimental results show that the orientation of the predominant root Cracks generally follows the contour of the fusion line. As the temperature increases from 25 °C to 150 °C, at first the root Crack rate decreases and then slightly increases at 150 °C. The root Crack rate obtained at 120 °C is the lowest. The fracture model changes from a brittle cleavage fracture to a mixture fracture with quasi-cleavage facets and dimples. The thermal cycle curves of laser hybrid welding obtained by temperature measurement systems are used to evaluate the Crack resistance and microstructure transformation. The microstructures of welded joints obtained at different temperatures are analyzed by optical microscope (OM). The results reveal that the microstructures of the coarse grained region and the fusion zone at 120 °C have higher Cold Crack resistance and good impact toughness. Mechanical properties of the welded joint obtained at 120 °C and 150 °C are comprehensively evaluated by microhardness test, uniaxial tensile test and charpy V-notch impact test with side notches. Fractographs of the impact specimens are studied by scanning electron microscopy (SEM). The test results show that the welded joints obtained at 120 °C have satisfactory mechanical properties that can meet the technical requirements for shipbuilding industry.
Jianguo Huang - One of the best experts on this subject based on the ideXlab platform.
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effects of preheating temperature on Cold Cracks microstructures and properties of high power laser hybrid welded 10ni3crmov steel
Materials & Design, 2011Co-Authors: L H Hu, Zhigang Li, Jianguo Huang, Y X WuAbstract:Abstract Laser hybrid welding has become one of the most promising welding methods for high strength low alloy steels due to combining the advantage of the laser and arc. A novel Y-groove Cold Cracking test adapted to laser hybrid welding is designed to assess the weldability of 10Ni3CrMoV steels at room temperature and different preheating temperatures. The experimental results show that the orientation of the predominant root Cracks generally follows the contour of the fusion line. As the temperature increases from 25 °C to 150 °C, at first the root Crack rate decreases and then slightly increases at 150 °C. The root Crack rate obtained at 120 °C is the lowest. The fracture model changes from a brittle cleavage fracture to a mixture fracture with quasi-cleavage facets and dimples. The thermal cycle curves of laser hybrid welding obtained by temperature measurement systems are used to evaluate the Crack resistance and microstructure transformation. The microstructures of welded joints obtained at different temperatures are analyzed by optical microscope (OM). The results reveal that the microstructures of the coarse grained region and the fusion zone at 120 °C have higher Cold Crack resistance and good impact toughness. Mechanical properties of the welded joint obtained at 120 °C and 150 °C are comprehensively evaluated by microhardness test, uniaxial tensile test and charpy V-notch impact test with side notches. Fractographs of the impact specimens are studied by scanning electron microscopy (SEM). The test results show that the welded joints obtained at 120 °C have satisfactory mechanical properties that can meet the technical requirements for shipbuilding industry.
Zhigang Li - One of the best experts on this subject based on the ideXlab platform.
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effects of preheating temperature on Cold Cracks microstructures and properties of high power laser hybrid welded 10ni3crmov steel
Materials & Design, 2011Co-Authors: L H Hu, Zhigang Li, Jianguo Huang, Y X WuAbstract:Abstract Laser hybrid welding has become one of the most promising welding methods for high strength low alloy steels due to combining the advantage of the laser and arc. A novel Y-groove Cold Cracking test adapted to laser hybrid welding is designed to assess the weldability of 10Ni3CrMoV steels at room temperature and different preheating temperatures. The experimental results show that the orientation of the predominant root Cracks generally follows the contour of the fusion line. As the temperature increases from 25 °C to 150 °C, at first the root Crack rate decreases and then slightly increases at 150 °C. The root Crack rate obtained at 120 °C is the lowest. The fracture model changes from a brittle cleavage fracture to a mixture fracture with quasi-cleavage facets and dimples. The thermal cycle curves of laser hybrid welding obtained by temperature measurement systems are used to evaluate the Crack resistance and microstructure transformation. The microstructures of welded joints obtained at different temperatures are analyzed by optical microscope (OM). The results reveal that the microstructures of the coarse grained region and the fusion zone at 120 °C have higher Cold Crack resistance and good impact toughness. Mechanical properties of the welded joint obtained at 120 °C and 150 °C are comprehensively evaluated by microhardness test, uniaxial tensile test and charpy V-notch impact test with side notches. Fractographs of the impact specimens are studied by scanning electron microscopy (SEM). The test results show that the welded joints obtained at 120 °C have satisfactory mechanical properties that can meet the technical requirements for shipbuilding industry.
Krishnasamy Senthilkumar - One of the best experts on this subject based on the ideXlab platform.
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Multi objective optimization of Cold Crack susceptibility of high strength low alloy steel 950A using Grey Relational Analysis
Materials Today: Proceedings, 2020Co-Authors: Velumani Manivelmuralidaran, Krishnasamy SenthilkumarAbstract:Abstract Cold Cracking is one of the problems associated with joining of high strength low alloy steels. The selection of optimum parameters for welding process decides the properties and joint integrity of the welds. The effects of process parameters on Cold Cracking susceptibility of HSLA 950A has been studied. Heat input, temperature of preheating and oxide particles content are taken as input parameters. Impact strength and Cracking percentage are taken as responses. In this work, the multi objective optimisation has been attempted using Grey Relational Analysis to optimize process parameters for controversial responses. The recommended parameter levels for the high grey relation grade has been determined. Heat input, preheating temperature and oxide particles that are added to the weld have equal contribution to the impact strength. The oxide particles that are added to the weld also an influence on the hydrogen induced Cold Cracking resistance of the HSLA 950A weld metal. Percentage increase in Grey Relational Grade is about 75%. The results of the model have been checked by conducting the confirmation experiment. The result lies within the acceptable level of confidence interval.
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artificial neural network modelling of Cold Crack resistance of high strength low alloy steel 950a
The Journal of Engineering, 2019Co-Authors: Velumani Manivelmuralidaran, Krishnasamy SenthilkumarAbstract:The objective of the study is to predict the Cold Cracking resistance of high strength low alloy 950A welded joints using an artificial neural network (ANN) model. A bead on plate welding is carried out using the gas metal arc welding process. The identified process parameters for the ANN are preheating temperature, oxide particle content, and heat input. The impact strength of the weld metal is considered as the output parameter. A feed-forward back propagation model with ten neurons in the hidden layer is developed to predict the impact strength of the weld metal. The neural network model is created, trained, and tested with a set of experimental data. The proposed model correctly predicted the impact strength of the given input parameters. The predicted value of the impact strength is in agreement with the experimental data. The error percentage between the predicted and observed values is <5% and the root mean square error value is 2.2%. Sensitivity analysis is performed to identify the significance of input parameters. It is evident that the preheating temperature contributes 50.04%, oxide particles content contributes 37.15%, and heat input contributes 12.81% to impact strength.