检索结果-南通市图书馆

Journal of Materials Science & Technology 2019年第9期35卷 1817-1824页

作者： Jingjing Yang Yun Wang Fangzhi Li Wenpu Huang Guanyi Jing Zemin Wang Xiaoyan Zeng Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Xi'an Space Engine Factory Xi'an710100China

Laser welding is a promising process for joining small components produced by selective laser melting (SLM) to fabricate the large-scale and complex-shaped parts. In the work, the morphology, microstructure, microhardness, tensile properties and corrosion resistance of the laser welded stress-relieved SLMed 304 stainless steel joints are investigated, as the different sections of stress-relieved SLMed 304 stainless steel are joined. Results show that the SLMed 304 stainless steel plates have a good laser weldability. The microstructure of laser-welded joints consists of the cellular dendrites in austenite matrix within columnar grains, exhibiting a coarser dendrite structure, lower microhardness (~220HV) and tensile properties (tensile strength of ~750 MPa, and area reduction of ~27.6%), but superior corrosion resistance to those of SLMed plates. The dendrite arm spacing of the joints varies from ~3.7μm in center zone, to ~5.0 (xm in fusion zone, to ~2.5 in epitaxial zone. The SLMed anisotropy shows a negligible effect on the microstructure and performance of the laser-welded joints. The laser welding along the building directions of the SLMed base plates can induce a slightly finer dendritic structure and higher tensile properties.

关键词： Selective laser melting Laser welding 304 stainless steel Anisotropy

Optimization of gas tungsten arc welding parameters for the dissimilar welding between AISI 304 and AISI 201 stainless steels

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2019年第2期15卷 170-178页

作者： Wichan Chuaiphan Loeshpahn Srijaroenpramong Department of Mechanical and Industrial Engineering Faculty of Engineering Rajamangala University of Technology Krungthep Department of Metallurgical Technology Faculty of Education Rajamangala University of Technology Krungthep

This present study applied gas tungsten arc welding in order to join AISI 304 and AISI 201 stainless *** objective was to find the optimum welding condition that gave a weld bead in accordance with DIN EN ISO 25817 quality level B, pitting corrosion potential of the weld metal of not less than that of the AISI304 base metal and a ratio of delta-ferrite in austenite matrix of the weld metal of not lower than 3%.Such a ratio is a criterion widely accepted to protect the weld metal from solidification cracking. At the welding current of 75 A and by using pure argon as a shielding gas 0 to 8 vol.% and applying a welding speed in the range of 2-3.5 mm·s^(-1) was found to give a complete weld bead with an increased depthper-width ratio(promote weldability). For welding speed in the range of 3 and 3.5 mm·s^(-1)(promote corrosion resistance). Increasing the welding speed in such a range decreased the amount of delta-ferrite in the austenite matrix, and increased the pitting corrosion potential of the weld metal to be 302 mV_(SCE).This value was still lower than the pitting corrosion potential of the AISI 304 base metal. Mixing nitrogen in argon shielding gas increased the nitrogen content in the weld. The optimum condition was found when using a welding speed of 3 mm· s^(-1) and mixing 1 vol.% of nitrogen in the argon shielding gas(promote weldability and corrosion resistance). Pitted areas after potentiodynamic test were observed in the austenite in which its Cr content was relatively low.

关键词： Dissimilar weldment AISI 304 stainless steel AISI 201 stainless steel Gas tungsten arc welding(GTAW) Nitrogen Corrosion behavior Mechanical behavior

Characterization of Passive Films Formed on As-received and Sensitized AISI 304 Stainless Steel

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2019年第2期32卷 61-72页

作者： Yubo Zhang Hongyun Luo Qunpeng Zhong Honghui Yu Jinlong Lv Key Laboratory of Aerospace Materials and Performance (Ministry of Education) School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics The Collaborative Innovation Center for Advanced Aero-Engine (CICAAE) Beijing University of Aeronautics and Astronautics Beijing Key Laboratory of Advanced Nuclear Materials and Physics Beijing University of Aeronautics and Astronautics China Waterborne Transport Research Institute Beijing Key Laboratory of Fine Ceramics Institute of Nuclear and New Energy Technology Tsinghua University

The current research of corrosion resistance of stainless steels mainly focuses on characterization of the passive films by point defect mode and mixed-conduction model. The corrosion resistance of the passive films formed on asreceived and sensitized AISI304 stainless steel in borate bu er solution were evaluated in this paper. The degree of sensitization and corrosion resistance of AISI304 stainless steels was evaluated by double loop electrochemical potentiodynamic reactivation and electrochemical impedance spectroscopy. The passive films formed on the stainless steels were studied by XPS technique. It was found that as-received specimen had higher pitting corrosion potential and corrosion resistance than sensitized one. The Mott-Schottky results showed that sensitized stainless steel had more defects in the passive film than as-received one. The compositions of the passive films were mainly Cr and Fe oxides according to XPS results.

关键词： 304 stainless steel Sensitization Passive films XPS Impedance

The role of atomic hydrogen and hydrogen-induced martensites in hydrogen embrittlement of type 304L stainless steel

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2002年第2期45卷 175-183页

作者：潘川褚武扬李正邦梁东图宿彦京乔利杰 Department of Welding Research Central Iron and steel Research Institute Beijing Beijing China Department of Materials Physics University of Science and Technology Beijing Beijing China

The role of atomic hydrogen and hydrogen-induced martensites in hydrogen embrittlement in slow strain rate tensile tests and hydrogen-induced delayed cracking (HIC) in sustained load tests for type 304 L stainless steel was quantitatively studied. The results indicated that hydrogen-induced martensites formed when hydrogen concentration C 0 exceeded 30 ppm, and increased with an increase in C 0, i.e. M(vol%)=62–82.5 exp (?C 0/102). The relative plasticity loss caused by the martensites increased linearly with increasing amount of the martensites, i.e. l δ(M), %=0.45 M (vol %)=27.9?37.1 exp(?C0/102). The plasticity loss caused by atomic hydrogen l δ(H) increased with an increase in C 0 and reached a saturation value l δ(H)max=40% when C 0>100 ppm. l δ(H) decreased with an increase in strain rate $\dot \varepsilon $ , i.e. l δ(H), $\% = - 21.9 - 9.9\dot \varepsilon $ , and was zero when $\dot \varepsilon \geqslant \dot \varepsilon _c = 0.032/s$ . HIC under sustained load was due to atomic hydrogen, and the threshold stress intensity for HIC decreased linearly with in C 0, i.e. K IH (Mpam1/2)=91.7?10.1 In C 0 (ppm). The fracture surface of HIC was dimple if K 1 was high or/and C 0 was low, otherwise it was quasi-cleavage. The boundary line between ductile and brittle fracture surface was K 1-54+25exp(?C 0/153)=0.

关键词： type 304 L stainless steel,hydrogen embrittlement,hydrogen-induced cracking,hydrogen-induced martensites.

Enhancing the Stability of Passive Film on 304 SS by Chemical Modification in Alkaline Phosphate–Molybdate Solutions

在线全文

学校读者我要写书评

暂无评论

Transactions of Tianjin University 2020年第2期26卷 135-141页

作者： Chengcheng Pan Yang Song Weixian Jin Zhenbo Qin Shizhe Song Wenbin Hu Da-Hai Xia Tianjin Key Laboratory of Composite and Functional Materials Tianjin 300354China School of Materials Science and Engineering Tianjin UniversityTianjin 300354China Zhoushan Marine Corrosion Institute of Central Research Institute of Iron and Steel Zhoushan 316003China

The purpose of this work was to enhance the corrosion resistance of the passive fi lm on 304 stainless steel(SS)by chemical modifi cation in alkaline phosphate–molybdate *** 304 SS was passivated in both phosphate and phosphate–molybdate mixed solutions to investigate the eff ect of molybdate on its corrosion *** experimental results indicated that the passive fi lm showed better corrosion resistance in Cl?-containing solutions after modifi cation in phosphate–molybdate solutions than in phosphate-only ***-dispersive spectroscopy analyses revealed that the passive fi lm formed in phosphate–molybdate solutions contained Mo and P after modifi cation,which is the reason for the enhanced corrosion resistance.

关键词： Passive fi lm 304 SS Corrosion Phosphate Molybdate

Influence of Welding Power to the Microstructure and Properties of 304 Stainless Steel Sheet Joints in CO_2 La-ser Welding

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S4期40卷 106-110页

作者： T Akiyama Japanese ICEMAN Corporation Ltd Fukuoka 8301111Japan

The optical microscope,SEM,XRD,microhardness and tensile tests are used to analyze the microstructure,microhardness and tensile strength of the joints of 304 stainless steel sheet joint by CO2 laser welding with different welding *** results show that microstructure of laser welding seam is the ferrite phase and austenite *** has an epitaxial solidification phenomenon and fine grains in the fusion *** the welding power is 1.4kW,the microhardness reaches a maximum value of 205HV in welding seam center,which is the transition zone of two directional dendritical *** coarser equiaxed grains lay in the 1.8kW welding seam center,and microhardness reached a minimum value of 195HV in the welding seam *** the welding power increases,the effective bearing area of lap welding seam builds up rapidly,and the maximum loads of the double welding seams joints also increase from 4500N to 6000N in tensile test.

关键词： laser welding 304 stainless steel microstructure properties

304不锈钢纤维/ZL104铝合金复合泡沫的孔结构、力学、吸声性能及其机理

在线全文

学校读者我要写书评

暂无评论

材料研究学报 2023年第3期37卷 175-183页

作者：苗琪左孝青周芸王应武郭路王坦黄蓓昆明理工大学材料科学与工程学院昆明650093 云南省科学技术院高新技术中心昆明650051

用渗流铸造法制备ZL104合金泡沫和304不锈钢纤维/ZL104合金复合泡沫,对比研究了两种泡沫的孔结构、力学和吸声性能及其机理。结果表明,调控盐(次盐)的作用使合金泡沫和复合泡沫的孔壁上出现次孔结构而生成多孔孔壁结构;纤维复合后的泡... 详细信息

用渗流铸造法制备ZL104合金泡沫和304不锈钢纤维/ZL104合金复合泡沫,对比研究了两种泡沫的孔结构、力学和吸声性能及其机理。结果表明,调控盐(次盐)的作用使合金泡沫和复合泡沫的孔壁上出现次孔结构而生成多孔孔壁结构;纤维复合后的泡沫以孔壁纤维、穿孔纤维和孔间纤维三种状态存在,与相同孔隙率的合金泡沫相比,复合泡沫的孔隙率为77%~86%、主孔径为0.35 mm、纤维直径为0.1 mm,具有更高的压缩性能和吸声性能。复合泡沫的压缩性能和吸声性能,都随着孔隙率和纤维含量的提高先提高后降低。孔隙率为82%的复合泡沫,纤维含量(体积分数)为5%时力学性能达到2.6 MPa,纤维含量为8%时其平均吸声系数(吸声性能)为0.893。有限元分析结果表明,复合泡沫受力时,孔壁纤维和穿孔纤维能传递和分散应力,并通过位移和偏转等方式消耗能量,使其强度提高;J-A模型分析结果表明,突出到孔隙中的纤维使复合泡沫的表面粗糙度和比表面积和声波在泡沫内的损耗增大,是其吸声性能较高的原因。

关键词：复合材料 304 不锈钢纤维/ZL104 复合泡沫渗流铸造吸声性能力学性能孔隙率

Bi_(2)S_(3)/CdS/TiO_(2)纳米复合材料的制备及对304不锈钢的光生阴极保护性能研究

在线全文

学校读者我要写书评

暂无评论

中国腐蚀与防护学报 2024年第2期44卷 372-380页

作者：叶梦颖于佳汇王彤彤高荣杰中国海洋大学材料科学与工程学院青岛266100

通过超声辅助连续离子层吸附和反应法在TiO_(2)纳米管上负载CdS和Bi_(2)S_(3),通过SEM、XRD、XPS等手段对材料的形貌、结构、元素组成和价态进行表征,在模拟太阳光下,系统研究TiO_(2)纳米复合材料的电化学性能。结果表明,负载CdS和Bi_(2... 详细信息

通过超声辅助连续离子层吸附和反应法在TiO_(2)纳米管上负载CdS和Bi_(2)S_(3),通过SEM、XRD、XPS等手段对材料的形貌、结构、元素组成和价态进行表征,在模拟太阳光下,系统研究TiO_(2)纳米复合材料的电化学性能。结果表明,负载CdS和Bi_(2)S_(3)的TiO_(2)纳米复合材料的光吸收范围扩展到可见光区,载流子的复合率也大大降低,光电流密度提升至850μA·cm-2,是改性前的3.4倍;将其与304不锈钢耦合后,电位降至-0.99 V,比改性前的耦合电位低约70 mV,可以进一步提升对304不锈钢的光生阴极保护效果。

关键词：光生阴极保护改性 Bi_(2)S_(3)/CdS/TiO_(2) 304 不锈钢

在线全文

学校读者我要写书评

暂无评论

SUS304不锈钢点焊接头疲劳寿命研究

机械强度 2023年第4期45卷 1005-1010页

作者：赵佳伟陶友瑞裴佳星张禹河北工业大学机械工程学院天津300401 秦皇岛烟草机械有限责任公司秦皇岛066000

为了准确预测工程机械上SUS304不锈钢点焊接头的疲劳寿命,提出了一种用于焊点寿命预测的S-N曲线。根据常见的几种点焊接头的结构形式,制备了不同板厚组合的拉剪疲劳试件,通过疲劳试验获取了试件的疲劳寿命数据。利用CT扫描实验获取了准... 详细信息

为了准确预测工程机械上SUS304不锈钢点焊接头的疲劳寿命,提出了一种用于焊点寿命预测的S-N曲线。根据常见的几种点焊接头的结构形式,制备了不同板厚组合的拉剪疲劳试件,通过疲劳试验获取了试件的疲劳寿命数据。利用CT扫描实验获取了准确的焊核直径,建立了试件的有限元模型,并通过光学应变测量试验验证了该模型的准确性。然后,基于Rupp等效结构应力法和疲劳试验数据建立了综合不同板厚组合和载荷比的结构应力-寿命曲线(S-N曲线),并使用Goodman修正法消除了载荷比的影响。最后,建立了振动输送机有限元模型,并进行瞬态动力学分析获取了振槽焊点的结构应力,基于建立的S-N曲线预测了焊点寿命。结果显示,振槽各焊点接头无疲劳问题,存在焊点冗余情况,可以做轻量化设计。

关键词： 304 不锈钢点焊 S-N 曲线疲劳寿命振动输送机

维普期刊数据库博看期刊

Effect of Pipe Diameter on Electrochemical Behavior of Stainless Steel Type 304 Pipes in Tap Water

在线全文

学校读者我要写书评

暂无评论

Materials Sciences and Applications 2019年第11期10卷 697-708页

作者： Noriyuki Tanaka Shigeru Sato Itaru Ikeda Tadahiko Uchida Motoki Kuratani Yutaka Yamada Osamu Sakurada Technical Research Laboratory DAI-DAN Co. Ltd. Saitama Japan Gifu University Gifu Japan

We investigated the effects of pipe diameter on the corrosion resistance of stainless steel type 304 pipes using electrochemical measurements. Compared to plate steel, pipes have harder physical properties and tend to be harder and showed greater permeability with decreasing inner diameter. We found that the maximum corrosion current density in the secondary active state, which is the starting point of secondary passivation, appeared in the polarization curve measurement in tap water. Similar to the Vickers hardness and the maximum current density in the secondary active state, the permeability tended to increase as the diameter decreased. This is thought to increase the amount of deformation-induced martensitic and increase corrosion susceptibility. The peak of the secondary active current density was clearly seen as the potential sweep speed was increased. In addition, potential sweep speed dependence was observed in the corrosion susceptibility evaluation of deformation-induced martensite. In comparison with acid treatment, the formation of deformation-induced martensite was considered to occur in the extreme surface layer. The maximum corrosion current density in the secondary active state is expected to be a new susceptibility evaluation method for evaluating the deformation-induced martensitic transformation.

关键词： Stainless Steel Type 304 Electrochemical Consideration Pipe Diameter Electrochemical Behavior Tap Water