Prior research in the development of 30% chromium-nickel alloy nuclear welding wires has resulted in the resolution of primary water stress corrosion cracking (PWSCC) and ductility dip cracking (DDC) as well as improvement in solidification cracking (SC) resistance. The resolution of DDC exhibits some Laves phase, which has a negative effect on SC resistance. In this study, the use of an alternate carbide former, tantalum (Ta), in combination with niobium (Nb) was researched. Three heats of recently designed Filler Metal 52MSS-Ta (i.e., HV1648, HV1673A, and VX131WXW) were melted, fabricated, and systematically studied. DDC and SC were evaluated with thermodynamic modeling using the Scheil solidification simulation model, two types of varestraint tests, and strain-to-fracture (STF) testing. The varestraint and STF test results showed an improved SC resistance with reduced Laves phase and concurrent excellent DDC resistance. Optimized compositions with low Laves phase also exhibited high threshold strain values (TSVs) in the STF test. VX131WXW — which contains 2.81 wt-% Ta, 0.6 wt-% Nb, and 6 wt-% iron (Fe) - exhibited a TSV of 24%. Thermo-Calc computed the Laves phase to be 0.24% for VX131WXW compared to 0.06% in HV1673A. This difference in Laves phase resulted in the lower SC resistance of VX131WXW compared to HV1673A when measured with longitudinal varestraint testing. The maximum crack distance for HV1673A was about 0.6 mm while that of heat VX131WXW was about 1.0 mm. The typical diluted weld deposit made with VX131WXW was also resistant to PWSCC due to the chromium content exceeding 24%. These simultaneous results mark progress toward crack-free welds and provide direction for further optimization of Ta-containing filler metals.
{"title":"Crack-Free 30% Chromium-Nickel Alloy Welding Products for Nuclear Service","authors":"S. Kiser, B. Baker, Zhili Feng, T. Dai, Yiyu Wang","doi":"10.29391/2022.101.024","DOIUrl":"https://doi.org/10.29391/2022.101.024","url":null,"abstract":"Prior research in the development of 30% chromium-nickel alloy nuclear welding wires has resulted in the resolution of primary water stress corrosion cracking (PWSCC) and ductility dip cracking (DDC) as well as improvement in solidification cracking (SC) resistance. The resolution of DDC exhibits some Laves phase, which has a negative effect on SC resistance. In this study, the use of an alternate carbide former, tantalum (Ta), in combination with niobium (Nb) was researched. Three heats of recently designed Filler Metal 52MSS-Ta (i.e., HV1648, HV1673A, and VX131WXW) were melted, fabricated, and systematically studied. DDC and SC were evaluated with thermodynamic modeling using the Scheil solidification simulation model, two types of varestraint tests, and strain-to-fracture (STF) testing. The varestraint and STF test results showed an improved SC resistance with reduced Laves phase and concurrent excellent DDC resistance. Optimized compositions with low Laves phase also exhibited high threshold strain values (TSVs) in the STF test. VX131WXW — which contains 2.81 wt-% Ta, 0.6 wt-% Nb, and 6 wt-% iron (Fe) - exhibited a TSV of 24%. Thermo-Calc computed the Laves phase to be 0.24% for VX131WXW compared to 0.06% in HV1673A. This difference in Laves phase resulted in the lower SC resistance of VX131WXW compared to HV1673A when measured with longitudinal varestraint testing. The maximum crack distance for HV1673A was about 0.6 mm while that of heat VX131WXW was about 1.0 mm. The typical diluted weld deposit made with VX131WXW was also resistant to PWSCC due to the chromium content exceeding 24%. These simultaneous results mark progress toward crack-free welds and provide direction for further optimization of Ta-containing filler metals.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45197748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deposition Rate in GMAW of ER1100 and ER5183 Aluminum Alloys","authors":"Zhaoyang Yan, Kevin Scott, Shujun Chen, P. Mendez","doi":"10.29391/2022.101.023","DOIUrl":"https://doi.org/10.29391/2022.101.023","url":null,"abstract":"Droplet temperature, wire resistivity, electrode extension.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47779032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The carbon fiber-reinforced polymer (CFRP) metal structure is widely used in various industries to reduce the weight and cost of the structure without compromising performance. The main challenge for manufacturing the CFRP metal structure comes from the lack of flexible and robust joining processes. In this study, a new laser joining process was developed that used a thin layer of polyamide 6 as an interlayer material lying between carbon fiber-reinforced thermosets and a quenching-partition (QP) 980 steel to achieve the joint since the laser can’t directly join the steel to the thermoset composite. It was found that the joint’s strength was seriously degraded by the porosity’s formation. The porosity formation mechanism was studied by online-recording the thermal history inside the joint during the laser joining process. Experimental results demonstrated that the emerging of the porosities in the joint was mainly caused by the cooling shrinkage instead of pyrolysis gas release. Furthermore, a new approach of controlling and optimizing the interfacial pressure was developed to suppress the porosity formation in the joint, which can significantly reduce the porosity rate from 25.8 to 1.2% and dramatically improve the joint shear strength from 10.69 to 18.6 MPa by 73.99%.
{"title":"Laser Joining of CFRTS and Steel by Interfacial Pressure Control","authors":"Jinyu Bai, Shanlu Yang, Zhe-An Lin, Qian Yin","doi":"10.29391/2022.101.022","DOIUrl":"https://doi.org/10.29391/2022.101.022","url":null,"abstract":"The carbon fiber-reinforced polymer (CFRP) metal structure is widely used in various industries to reduce the weight and cost of the structure without compromising performance. The main challenge for manufacturing the CFRP metal structure comes from the lack of flexible and robust joining processes. In this study, a new laser joining process was developed that used a thin layer of polyamide 6 as an interlayer material lying between carbon fiber-reinforced thermosets and a quenching-partition (QP) 980 steel to achieve the joint since the laser can’t directly join the steel to the thermoset composite. It was found that the joint’s strength was seriously degraded by the porosity’s formation. The porosity formation mechanism was studied by online-recording the thermal history inside the joint during the laser joining process. Experimental results demonstrated that the emerging of the porosities in the joint was mainly caused by the cooling shrinkage instead of pyrolysis gas release. Furthermore, a new approach of controlling and optimizing the interfacial pressure was developed to suppress the porosity formation in the joint, which can significantly reduce the porosity rate from 25.8 to 1.2% and dramatically improve the joint shear strength from 10.69 to 18.6 MPa by 73.99%.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43817596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dongsheng Wu, Junhao Sun, Zhuguo Li, Jian Huang, Ke Feng
Thin copper materials are difficult to weld using infrared lasers (IR) due to their low energy absorption. A blue laser with a wavelength of 450 nm strongly increases energy absorption and successfully realized the microjoining of a copper material with a thickness of 0.1 mm. The dynamic behaviors of a thin molten pool were investigated by a numerical simulation using a new blue laser heat source model. At both the top and bottom surfaces of the thin molten pool, the liquid metal flowed outward under the driving of Marangoni stress. The stability of the thin molten pool was studied, showing that Marangoni stress promoted the melt-through of the thin molten pool, while the viscous resistant stress, buoyant force, and surface tension pressure had minor influences on it. The Peclet and Marangoni numbers were adopted to predict the stability of the thin molten pool.
{"title":"Thin Molten Pool Behaviors in Blue Laser Microjoining","authors":"Dongsheng Wu, Junhao Sun, Zhuguo Li, Jian Huang, Ke Feng","doi":"10.29391/2022.101.021","DOIUrl":"https://doi.org/10.29391/2022.101.021","url":null,"abstract":"Thin copper materials are difficult to weld using infrared lasers (IR) due to their low energy absorption. A blue laser with a wavelength of 450 nm strongly increases energy absorption and successfully realized the microjoining of a copper material with a thickness of 0.1 mm. The dynamic behaviors of a thin molten pool were investigated by a numerical simulation using a new blue laser heat source model. At both the top and bottom surfaces of the thin molten pool, the liquid metal flowed outward under the driving of Marangoni stress. The stability of the thin molten pool was studied, showing that Marangoni stress promoted the melt-through of the thin molten pool, while the viscous resistant stress, buoyant force, and surface tension pressure had minor influences on it. The Peclet and Marangoni numbers were adopted to predict the stability of the thin molten pool.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44693289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The coarse-grained heat-affected zone (CGHAZ) samples were prepared from T23 steel with three different carbon contents on a thermal simulator, then isothermal slow strain rate tensile tests were carried out at 500° ~ 750°C, and the effect of carbon content on the stress-relief cracking (SRC) sensitivity of T23 steel was evaluated according to fracture ductility. The microstructure evolution of the CGHAZs in the process of SRC was observed by optical microscopy, structural equation modeling energy-dispersive spectroscopy, and transmission electron microscopy energy-dispersive spectroscopy/selected area electron diffraction to reveal the mechanism of SRC. Finally, the feasibility of adjusting carbon content to prevent SRC was discussed. The results showed the classical theory of intragranular precipitation hardening cannot explain the cause of SRC, and a new viewpoint was put forward that the precipitation of M23C6 at the grain boundary was the main reason for SRC. The precipitation of M23C6 carbide cannot only provide a preferred site for void nucleation but also leads to the depletion of alloy elements in the matrix near the grain boundary. The interaction of these two aspects leads to the direct weakening of grain boundaries. Moreover, the SRC of T23 steel could be inhibited when the carbon content was determined to be close to the ASME standard lower limit of 0.04 wt-%. In summary, reducing the carbon content can inhibit the SRC sensitivity of T23 steel, which is not due to reducing the relative weakening of the grain boundary by reducing the precipitation hardening in the grain interior but to inhibiting the direct weakening of the grain boundary by reducing the precipitation of M23C6 at the grain boundary.
{"title":"Effect of Carbon on Stress-Relief Cracking Susceptibility of T23 Steel","authors":"Xue Wang, Dongdong Zhang, Yong Li, Xianhong Lai, Wei Zhang","doi":"10.29391/2022.101.020","DOIUrl":"https://doi.org/10.29391/2022.101.020","url":null,"abstract":"The coarse-grained heat-affected zone (CGHAZ) samples were prepared from T23 steel with three different carbon contents on a thermal simulator, then isothermal slow strain rate tensile tests were carried out at 500° ~ 750°C, and the effect of carbon content on the stress-relief cracking (SRC) sensitivity of T23 steel was evaluated according to fracture ductility. The microstructure evolution of the CGHAZs in the process of SRC was observed by optical microscopy, structural equation modeling energy-dispersive spectroscopy, and transmission electron microscopy energy-dispersive spectroscopy/selected area electron diffraction to reveal the mechanism of SRC. Finally, the feasibility of adjusting carbon content to prevent SRC was discussed. The results showed the classical theory of intragranular precipitation hardening cannot explain the cause of SRC, and a new viewpoint was put forward that the precipitation of M23C6 at the grain boundary was the main reason for SRC. The precipitation of M23C6 carbide cannot only provide a preferred site for void nucleation but also leads to the depletion of alloy elements in the matrix near the grain boundary. The interaction of these two aspects leads to the direct weakening of grain boundaries. Moreover, the SRC of T23 steel could be inhibited when the carbon content was determined to be close to the ASME standard lower limit of 0.04 wt-%. In summary, reducing the carbon content can inhibit the SRC sensitivity of T23 steel, which is not due to reducing the relative weakening of the grain boundary by reducing the precipitation hardening in the grain interior but to inhibiting the direct weakening of the grain boundary by reducing the precipitation of M23C6 at the grain boundary.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42160890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muralimohan Cheepu, Hyo Jin Baek, Young Sik Kim, Sang-Myung Cho
This study proposes a novel method to estimate the weld penetration in gas tungsten arc welding (GTAW) with filler metal. So far, there is no standard parameter available to accurately estimate penetration in GTAW with filler metal. Until now, the penetration could be estimated by heat input only in GTAW with and without filler metal. But in this study, it was revealed that the conventional heat input could not accurately estimate the penetration in GTAW with filler metal. Therefore, the new concept of net heat input ratio (NHIR), which is a ratio of net heat input to the bead cross-sectional area, was developed to accurately estimate the penetration in GTAW with filler metal. Using a C-type filler metal during GTAW, the NHIR was calculated for various welding conditions. The results showed that the NHIR was proportional to the welding current and voltage and inversely proportional to the welding speed and filler feed speed. Even though the NHIR was the same, the penetration increased as the welding current became higher. Four linear equations between NHIR and penetration were obtained from the experimental results for four levels of welding currents. By applying the concept of NHIR, the penetration could be estimated for any welding current.
{"title":"Penetration Estimation of GTAW with C-Type Filler by Net Heat Input Ratio","authors":"Muralimohan Cheepu, Hyo Jin Baek, Young Sik Kim, Sang-Myung Cho","doi":"10.29391/2022.101.018","DOIUrl":"https://doi.org/10.29391/2022.101.018","url":null,"abstract":"This study proposes a novel method to estimate the weld penetration in gas tungsten arc welding (GTAW) with filler metal. So far, there is no standard parameter available to accurately estimate penetration in GTAW with filler metal. Until now, the penetration could be estimated by heat input only in GTAW with and without filler metal. But in this study, it was revealed that the conventional heat input could not accurately estimate the penetration in GTAW with filler metal. Therefore, the new concept of net heat input ratio (NHIR), which is a ratio of net heat input to the bead cross-sectional area, was developed to accurately estimate the penetration in GTAW with filler metal. Using a C-type filler metal during GTAW, the NHIR was calculated for various welding conditions. The results showed that the NHIR was proportional to the welding current and voltage and inversely proportional to the welding speed and filler feed speed. Even though the NHIR was the same, the penetration increased as the welding current became higher. Four linear equations between NHIR and penetration were obtained from the experimental results for four levels of welding currents. By applying the concept of NHIR, the penetration could be estimated for any welding current.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46621703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Coal-fired power plants often have welded joints made up of 347H stainless steel. However, this alloy is known to fail because of stress relaxation cracking. Thus, quantitative evaluation methods are needed as screening measures. In this study, a Gleeble® thermomechanical simulator was implemented in 347H and Super 304H alloy heat-affected zone (HAZ) simulation and stress relaxation testing. In the case of 347H, carbide dissolution in the HAZ reduced the hardness value and promoted grain growth. Alternatively, the respective extent of precipitate dissolution and hardness reduction in the nitrogen-containing Super 304H was relatively small. The stress relaxation tests were performed at a temperature of 700°C (1292°F), which was maintained for up to 70 h. Consequently, all 347H specimens fractured within 32 h. Furthermore, the time to rupture substantially decreased as the strain was increased from 5 to 10% and then to 15%. Additionally, the hardness near the fractured surface increased, and the plastic deformation primarily occurred near the grain boundaries. Conversely, the Super 304H specimens did not fracture during the 70-h testing period, at which time their hardness distribution was observed to still be relatively uniform. These results demonstrate that the susceptibility of stress relaxation cracking can be quantitatively determined according to the material and strain.
{"title":"Comparison of Stress Relaxation Cracking Susceptibility of Austenitic Stainless Steels","authors":"H. Lee, Bumcho Kim, Sun-Ig Hong","doi":"10.29391/2022.101.017","DOIUrl":"https://doi.org/10.29391/2022.101.017","url":null,"abstract":"Coal-fired power plants often have welded joints made up of 347H stainless steel. However, this alloy is known to fail because of stress relaxation cracking. Thus, quantitative evaluation methods are needed as screening measures. In this study, a Gleeble® thermomechanical simulator was implemented in 347H and Super 304H alloy heat-affected zone (HAZ) simulation and stress relaxation testing. In the case of 347H, carbide dissolution in the HAZ reduced the hardness value and promoted grain growth. Alternatively, the respective extent of precipitate dissolution and hardness reduction in the nitrogen-containing Super 304H was relatively small. The stress relaxation tests were performed at a temperature of 700°C (1292°F), which was maintained for up to 70 h. Consequently, all 347H specimens fractured within 32 h. Furthermore, the time to rupture substantially decreased as the strain was increased from 5 to 10% and then to 15%. Additionally, the hardness near the fractured surface increased, and the plastic deformation primarily occurred near the grain boundaries. Conversely, the Super 304H specimens did not fracture during the 70-h testing period, at which time their hardness distribution was observed to still be relatively uniform. These results demonstrate that the susceptibility of stress relaxation cracking can be quantitatively determined according to the material and strain.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49130614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new process is introduced for repair of structural components of aluminum alloys. Additive manufacturing, maintenance and repair welding, Al alloy, mechanical properties.
介绍了一种用于铝合金结构件修复的新工艺。增材制造，焊接维修保养，铝合金，机械性能。
{"title":"Wire-Based Friction Stir Additive Manufacturing toward Field Repairing","authors":"Huizi Chen, Jialin Chen, Xiangchen Meng, Yuming Xie, Yongxian Huang, Shunbi Xu, Yaobang Zhao","doi":"10.29391/2022.101.019","DOIUrl":"https://doi.org/10.29391/2022.101.019","url":null,"abstract":"A new process is introduced for repair of structural components of aluminum alloys. Additive manufacturing, maintenance and repair welding, Al alloy, mechanical properties.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41925565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One defect encountered in the fusion zone when welding aluminum alloys involves solidification cracking (i.e., the tearing apart of grain boundary liquid films at the trailing edge of the weld pool). This problem can often be mitigated by the proper selection of filler metal. Two key engineering examples, one aerospace and one maritime, where this has occurred were examined in terms of alloy development to achieve optimum mechanical properties while maintaining weldability. Specifically, base metal/filler metal systems susceptible to cracking were examined in terms of filler metal dilution. A mechanism for crack growth was presented based upon critical strain rate. Conditions needed for improved weldability through grain refinement were defined based upon the columnar-to-equiaxed solidification theory.
{"title":"Applying Solidification Theory to Aluminum Weldability and Consumable Development","authors":"C. Cross","doi":"10.29391/2022.101.016","DOIUrl":"https://doi.org/10.29391/2022.101.016","url":null,"abstract":"One defect encountered in the fusion zone when welding aluminum alloys involves solidification cracking (i.e., the tearing apart of grain boundary liquid films at the trailing edge of the weld pool). This problem can often be mitigated by the proper selection of filler metal. Two key engineering examples, one aerospace and one maritime, where this has occurred were examined in terms of alloy development to achieve optimum mechanical properties while maintaining weldability. Specifically, base metal/filler metal systems susceptible to cracking were examined in terms of filler metal dilution. A mechanism for crack growth was presented based upon critical strain rate. Conditions needed for improved weldability through grain refinement were defined based upon the columnar-to-equiaxed solidification theory.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48825883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanming Wu, J. Shan, Z. Li, Xinghua Wang, Yan Feng, Ming-lin Wang
In this study, a sine-oscillating laser was used to obtain narrow groove laser-arc hybrid welding (NGHW) of high-strength low-alloy (HSLA) steel. Then the effects of laser beam oscillation amplitude and space constraint on arc behavior, droplet transfer, weld geometry, and incomplete fusion of the weld beads were analyzed. Due to the minimum arc voltage principle and inherent arc self-regulation, when the laser did not oscillate, it was observed that the arc cathode spot was typically attached to one sidewall. As a result, the molten pool did not spread through the entire width of the gap , resulting in incomplete fusion. When the laser beam oscillated in a sinusoidal path, the energy density on both sides of the amplitude was higher than the centerline, and the aspect ratio of the weld decreased. The speed of the beam along the centerline was found to be much higher than the speed on both sides of the amplitude. The molten pool oscillated in the width direction under the action of the oscillating beam, forming a concave surface, which promoted melting of the sidewalls of the groove and suppressed incomplete fusion defects in the sidewalls. The technical feasibility of NGHW assisted by laser beam oscillation was verified using a 60-mm-thick weld, which was haracterized by a smooth layer transition and the absence of visible defects.
{"title":"•Narrow Groove Laser-Arc Hybrid Welding of Thick-Sectioned HSLA Steel Using Laser Beam Oscillation","authors":"Yanming Wu, J. Shan, Z. Li, Xinghua Wang, Yan Feng, Ming-lin Wang","doi":"10.29391/2022.101.014","DOIUrl":"https://doi.org/10.29391/2022.101.014","url":null,"abstract":"In this study, a sine-oscillating laser was used to obtain narrow groove laser-arc hybrid welding (NGHW) of high-strength low-alloy (HSLA) steel. Then the effects of laser beam oscillation amplitude and space constraint on arc behavior, droplet transfer, weld geometry, and incomplete fusion of the weld beads were analyzed. Due to the minimum arc voltage principle and inherent arc self-regulation, when the laser did not oscillate, it was observed that the arc cathode spot was typically attached to one sidewall. As a result, the molten pool did not spread through the entire width of the gap , resulting in incomplete fusion. When the laser beam oscillated in a sinusoidal path, the energy density on both sides of the amplitude was higher than the centerline, and the aspect ratio of the weld decreased. The speed of the beam along the centerline was found to be much higher than the speed on both sides of the amplitude. The molten pool oscillated in the width direction under the action of the oscillating beam, forming a concave surface, which promoted melting of the sidewalls of the groove and suppressed incomplete fusion defects in the sidewalls. The technical feasibility of NGHW assisted by laser beam oscillation was verified using a 60-mm-thick weld, which was haracterized by a smooth layer transition and the absence of visible defects.","PeriodicalId":23681,"journal":{"name":"Welding Journal","volume":null,"pages":null},"PeriodicalIF":2.2,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44891331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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