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Influence of Thermal Modification on Al-Si Coating of Hot-Stamped 22MnB5 Steel:Microstructure,Phase Transformation,and Mechanical Properties

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Journal of Shanghai Jiaotong university(Science) 2021年第6期26卷 747-756页

作者： WANG Qiongyan LIN Wenhu LI Fang SHEN Chen hua xueming School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Center for Adaptive System Engineering ShanghaiTech UniversityShanghai 201210China

The hot-stamped steel with ultrahigh strength is a promising material for the fabrication of automotive ***,the coating on the sheet surface leads to a softening problem in the welded *** of the costly coating removal process,heat treatment is an economical and effective method for the diffusion process,which can decrease the Al concentration in the *** this study,a preheating treatment was carried out on Al-Si-coated 22MnB5 hot-stamped steels for the homogeneity of Al,followed by laser welding and hot *** effects of the preheating on the microstructure and mechanical properties of the laser-welded joints were *** the preheating treatment,the Al-Si coating transformed into an Fe-Al intermetallic compound and the difference in Al content between the coating and substrate was *** Al content in the weld of the specimen with the preheating treatment was reduced,compared with that without the preheating *** amount ofδ-ferrite in the weld after laser welding was reduced *** distribution of long-bland-like segregation was changed to a fine and uniform *** the preheating treatment,the tensile strength of the welded joint was significantly improved and comparable to that of the decoated *** conclusion,the preheating treatment before the welding is an effective method to suppress the formation ofδ-ferrite and improve the mechanical properties of the welded joint.

关键词： hot-stamped steel laser welding Al-Si coating microstructure mechanical properties

Different metabolomic responses of grass carp(Ctenopharyngodon idellus)to dietary tannin and rapeseed meal

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Aquaculture and Fisheries 2022年第1期7卷 40-51页

作者： Jingting Yao Ning Liu Ningyu Li Xiang Li xueming hua Centre for Research on Environmental Ecology and Fish Nutrition(CREEFN)of the Ministry of Agriculture Shanghai Ocean UniversityShanghai201306China Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of AgricultureShanghai201306China National Demonstration Center for Experimental Fisheries Science Education Shanghai Ocean UniversityShanghai201306China College of Food Science&Technology Shanghai Ocean UniversityShanghai201306China

In order to study the metabolomic responses of rapeseed meal on grass carp and the role that tannin plays in those responses,grass carp were fed four diets for an eight week *** were practical diets:FM diet contained 10%fishmeal without rapeseed meal,RM diet contained 50%rapeseed meal without fishmeal;the other two were semi-purified diets without(T0)or with 1.25%(T1)of supplemental hydrolysable *** tannin content in the RM diet was close to that of *** rate of weight gain for RM was significantly lower than FM,while the feed conversion ratio in the T1 was significantly higher than *** muscle lipid and protein content was significantly lower and glycogen higher in the RM and T1 compared to the other *** percent of muscle-saturated fatty acid(SFA)in the RM and T1 groups was significantly lower than FM and T0 groups,respectively,while the mono-unsaturated fatty acid(MUFA)in the RM group was significantly higher than *** hepatic activities of alanine aminotransferase and aspartate aminotransferase were lower and the hepatic glycogen and malonaldehyde were higher in the T1 and RM than the other *** total serum protein,globulin,and triglycerides were significantly higher in T1 and RM;the alanine aminotransferase in the T1 was significantly higher than T0;and the aspartate aminotransferase in the RM and T0 groups were significantly higher than the other *** a metabolomic assay,29 differential metabolites were identified between T0 and T1,23 metabolites were downregulated,and 6 metabolites were upregulated in T1 compared to ***-two differential metabolites were identified between FM and RM,31 metabolites were downregulated,and 61 metabolites were upregulated in RM compared to *** indicated that lipid utilization and carbohydrate metabolism might be improved,while the protein metabolism was suppressed by rapeseed *** abnormal protein and lipid metabolism may be partly caused by tannin in the rapeseed meal

关键词： Ctenopharyngodon idellus Hydrolysable tannin Rapeseed meal Metabolite Metabolic pathway

Effects of dietary vitamin K_(3) levels on growth,coagulation,calcium content,and antioxidant capacity in largemouth bass,Micropterus salmoides

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Aquaculture and Fisheries 2023年第2期8卷 159-165页

作者： Xiang Wei Ying Hang Xiang Li xueming hua Xiangming Cong Wanting Yi Xu Guo Centre for Research on Environmental Ecology and Fish Nutrition(CREEFN)of the Ministry of Agriculture Shanghai Ocean UniversityShanghai201306China Key Laboratory of Freshwater Aquatic Genetic Resources Ministry of AgricultureShanghai Ocean UniversityShanghai201306China National Demonstration Center for Experimental Fisheries Science Education Shanghai Ocean UniversityShanghai201306China

An 8-week feeding trial investigated the optimum dietary vitamin K3 requirements of largemouth bass.A total of 600 healthy fish(12.96±0.07 g)were fed diets containing varying levels of vitamin K3 at 0.78(K0),5.80(K5),10.82(K10),15.84(K15),and 20.85(K20)mg/kg with four replicates per *** showed that dietary vitamin K3 enhanced growth,with weight gain rate and specific growth rate in K15 trials significantly higher than K0 trials(P0.05).However,the supplementation of vitamin K3 significantly contributed to calcium accumulation in muscle tissues and vertebrae(P0.05).The antioxidant capacity was improved with the addition of vitamin K3,which was inconsistent with the changes in malondialdehyde and MK-4(a form of menaquinone)within liver and serum,suggesting that the toxicity of excessive artificial vitamin K3 may account for this *** regression analysis,the appropriate dietary vitamin K3 levels within a largemouth bass diet was determined to be in the range of 9.93-15.22 mg/kg,which will provide a reference for the preparation of vitamin premix and artificial diet for largemouth bass.

关键词： Growth Blood coagulation Antioxidant capacity Largemouth bass Vitamin K3

High Efficiency and Quality of Multi-Pass Tandem Gas Metal Arc Welding for Thick Al 5083 Alloy Plates

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Journal of Shanghai Jiaotong university(Science) 2019年第2期24卷 148-157页

作者： JIANG Zhao hua xueming huaNG Lijin WU Dongsheng LI Fang CAI Yan Shanghai Key Laboratory of Materials Laser Processing and Modification Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai Jiao Tong University

Multi-pass tandem gas metal arc welding(TGMAW) for Al 5083 alloy plates with 30 mm thickness is carried out to study its high efficiency and high quality. The welding process is evaluated by high-speed photographs and electrical signals. The deposition rate and welding time are calculated to characterize the welding efficiency. The bead formation, porosity, microstructure and mechanical properties are tested and analyzed. The results indicate that though arc deflection occurs due to the electromagnetic interference between two arcs during TGMAW process, it does not affect the welding process stability significantly. The deposition rate and welding time of TGMAW process are about 15 g/min larger and about 16.7% less than those of gas metal arc welding(GMAW)process respectively, accompanied by the reduction of heat input. The TGMAW welded joint has less porosity and more refined microstructure to contribute to the improvement of mechanical properties(micro-hardness, tensile strength and ductility). It can be concluded that TGMAW process yields excellent performance of welded joint with improved welding efficiency, which makes it extremely practical during welding of thick plates.

关键词： multi-pass welding tandem gas metal arc welding(TGMAW) welding efficiency porosity microstructure mechanical property

Serum osmolality and ions,and gill Na^(+)/K^(+)-ATPase of spottedtail goby Synechogobius ommaturus(R.)in response to acute salinity changes

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Aquaculture and Fisheries 2018年第2期3卷 79-83页

作者： Chun Shui Yonghai Shi xueming hua Zhonghua Zhang Haiming Zhang Genhai Lu Yongde Xie Key Laboratory of Freshwater Fishery Germplasm Resources Ministry of AgricultureShanghai Ocean UniversityShanghai 201306China Shanghai Fisheries Research Institute Shanghai 200433China

This study was carried out to determine the effects of abrupt salinity change on osmoregulatory ability of the spottedtail goby Synechogobius ommaturus.720 juvenile fish(65.3±11.8 g)were transferred to 200 L tanks(with 40 juveniles in each tank),in which salinities were abruptly changed from 10 to 20,30,40,50 and *** rate,serum osmolality,electrolytes(Na^(+),Cl^(-),and K^(+))and gill Na^(+)/K^(+)-ATPase(NKA)activity were assessed successively in 528 *** showed serum osmolality,ion concentrations and gill Na^(+)/K^(+)-ATPase activity increased significantly when fish were transferred to salinity 40 and 50 and all fish in these groups died by the end of the *** osmolality,Na^(+),Cl^(-)and K^(+)in fish transferred to a salinity of 20,30 and freshwater were not affected and no mortality was *** with the control group,a significantly decrease of NKA activity happened in the freshwater group,but the activity in 20 and 30 groups was not affected *** results indicated that *** could adapt rapidly and maintain homeostasis in a wide range of salinities(from freshwater to salinity 30)and this species may be suitable for aquaculture in estuarine and coastal areas where rapid salinity fluctuations commonly occur.

关键词： Osmolality Gill Na^(+)/K^(+)-ATPase Synechogobius ommaturus

铝硅镀层热成形钢拼焊板箔材填充激光焊的组织与性能研究

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焊接学报 2023年第6期44卷 90-94,I0008页

作者：林文虎李芳华学明上海科技大学创意与艺术学院智造系统工程中心上海201210 上海交通大学材料科学与工程学院上海市激光制造与材料改性重点实验室上海200240

铝硅镀层热成形钢是一种重要的汽车用先进高强钢,但在拼焊板制造过程中受到铝硅镀层的影响,焊接接头的性能远低于母材.文中选择了3种相同厚度不同箔材作为铝硅镀层热成形钢激光焊的填充材料,并经热成形工艺处理.通过比较焊接接头的微观... 详细信息

铝硅镀层热成形钢是一种重要的汽车用先进高强钢,但在拼焊板制造过程中受到铝硅镀层的影响,焊接接头的性能远低于母材.文中选择了3种相同厚度不同箔材作为铝硅镀层热成形钢激光焊的填充材料,并经热成形工艺处理.通过比较焊接接头的微观组织、硬度分布、拉伸力学性能和断口形貌,阐明不同箔材填充激光焊的影响作用.结果表明,Ni箔和Cu箔都促进了焊缝板条马氏体比例的增加和δ铁素体比例的减少,但Cu箔填充接头的断口呈沿晶断裂,塑性远低于Ni箔,与Ni固溶增强增韧Fe基体有关.Fe箔在一定程度上产生稀释的作用,也提高了焊缝板条马氏体含量.

关键词：热成形钢激光拼焊填充

光纤激光与GMAW-P复合焊接等离子体及熔滴过渡动态特征研究

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中国激光 2017年第4期44卷 83-88页

作者：李敏张旺华学明李芳上海电力学院能源与机械工程学院上海200090 上海交通大学上海市激光制造与材料改性重点实验室上海200240 液化空气(中国)研发有限公司上海200233

研究了高功率光纤激光与脉冲气体保护焊(GMAW-P)复合焊接中的等离子体动态行为、熔滴过渡模式以及电信号特征。结果表明,光纤激光焊接可以采用纯Ar气作为保护气体,GMAW-P电弧与光纤激光复合后会导致激光等离子体膨胀增大,电弧的弧长变... 详细信息

研究了高功率光纤激光与脉冲气体保护焊(GMAW-P)复合焊接中的等离子体动态行为、熔滴过渡模式以及电信号特征。结果表明,光纤激光焊接可以采用纯Ar气作为保护气体,GMAW-P电弧与光纤激光复合后会导致激光等离子体膨胀增大,电弧的弧长变短。比较电压概率密度可以看出,激光引导模式相较于电弧引导模式时的负载动态波动更为剧烈。

关键词：激光技术光纤激光复合焊接焊接等离子体熔滴过渡模式

304L不锈钢扫描激光搭接焊熔池流动与焊缝成形研究

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中国激光 2022年第22期49卷 69-76页

作者：杨晖李芳华学明陈科上海交通大学材料科学与工程学院激光制造与材料改性重点实验室上海200240

针对MARK III型液化天然气(LNG)船围护系统中的304L不锈钢波纹板搭接接头进行了圆形扫描激光焊接工艺研究。对于圆形扫描激光焊接的搭接接头,其下板焊缝边缘存在咬边,且在较大扫描幅度和较高扫描频率下咬边现象尤其明显。通过高速摄影发... 详细信息

针对MARK III型液化天然气(LNG)船围护系统中的304L不锈钢波纹板搭接接头进行了圆形扫描激光焊接工艺研究。对于圆形扫描激光焊接的搭接接头,其下板焊缝边缘存在咬边,且在较大扫描幅度和较高扫描频率下咬边现象尤其明显。通过高速摄影发现,焊接过程中圆形扫描轨迹内部存在未熔化区域。激光斑点除自身的扫描运动外还叠加了沿焊接方向的移动,随着扫描路径的重复叠加,在扫描激光焊接熔池的内部,未熔化区域逐渐减小,最终达到稳定状态。当扫描幅度或频率提高时,单位长度母材吸收的激光能量减小,熔池温度降低,当前扫描周期下形成的熔池前沿快速凝固,从而导致未熔化区尺寸无法进一步缩小。当扫描幅度降至1.5 mm或者扫描频率降至50 Hz时,未熔化区域较小甚至完全消失,咬边现象也随之消失。

关键词：激光技术扫描激光焊接咬边搭接焊圆形扫描 304L不锈钢

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光束焦点位置对双相不锈钢光纤激光焊接焊缝成形和组织的影响

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上海交通大学学报 2017年第4期51卷 418-425页

作者：赖睿蔡艳吴岳华学明上海交通大学材料科学与工程学院上海市激光制造与材料改性重点实验室上海200240

通过焊接热模拟方法和现代材料组织分析技术,研究了光束焦点位置对于双相不锈钢2205光纤激光焊接焊缝成形和组织的影响.结果表明,激光焦点位置影响了接头温度场分布,随着激光焦点下移进入工件内,焊缝上部逐渐收窄变短,焊缝内气孔数量显... 详细信息

通过焊接热模拟方法和现代材料组织分析技术,研究了光束焦点位置对于双相不锈钢2205光纤激光焊接焊缝成形和组织的影响.结果表明,激光焦点位置影响了接头温度场分布,随着激光焦点下移进入工件内,焊缝上部逐渐收窄变短,焊缝内气孔数量显著下降,热影响区尺寸无显著改变.此外,光束焦点位置对双相不锈钢焊缝组织具有影响.正离焦时,焊缝中部的奥氏体含量最高;当离焦量为0mm时,焊缝金属上部、中部和下部的奥氏体分布最为均匀.

关键词：双相不锈钢光纤激光焊接两相比焊缝组织