scholarly journals Microstructure and Corrosion Resistance of Underwater Laser Cladded Duplex Stainless Steel Coating after Underwater Laser Remelting Processing

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4965
Author(s):  
Congwei Li ◽  
Jialei Zhu ◽  
Zhihai Cai ◽  
Le Mei ◽  
Xiangdong Jiao ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Phase Composition ◽  
Duplex Stainless Steel ◽  
Electrochemical Corrosion ◽  
Chemical Components ◽  
Laser Remelting ◽  
Underwater Environment ◽  
Underwater Laser ◽  
Electrochemical Corrosion Resistance

Combined with the technologies of underwater local dry laser cladding (ULDLC) and underwater local dry laser remelting (ULDLR), a duplex stainless steel (DSS) coating has been made in an underwater environment. The phase composition, microstructure, chemical components and electrochemical corrosion resistance was studied. The results show that after underwater laser remelting, the phase composition of DSS coating remains unchanged and the phase transformation from Widmanstätten austenite + intragranular austenite + (211) ferrite to (110) ferrite occurred. The ULDLR process can improve the corrosion resistance of the underwater local dry laser cladded coating. The corrosion resistance of remelted coating at 3 kW is the best, the corrosion resistance of remelted coating at 1kW and 5kW is similar and the corrosion resistance of (110) ferrite phase is better than grain boundary austenite phase. The ULDLC + ULDLR process can meet the requirements of efficient underwater maintenance, forming quality control and corrosion resistance. It can also be used to repair the surface of S32101 duplex stainless steel in underwater environment.

Structure and Corrosion Resistance of Iron Coatings Containing Silicon Powders

2011 ◽  
Vol 399-401 ◽  
pp. 1926-1931 ◽  
Author(s):  
Yi Wang ◽  
Gang Chen ◽  
Wei Dong Liu ◽  
Qiong Yu Zhou ◽  
Qing Dong Zhong
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Thermal Treatment ◽  
Surface Morphology ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Active Surface ◽  
Active Surface Area ◽  
Two Phase ◽  
Electrochemical Corrosion Resistance

Fe + Si coatings were prepared by iron deposition from a bath containing a suspension of silicon powders. These coatings were obtained at galvanostatic conditions, at the current density of jdep=−0.020 A cm−2 and at the temperature of 338 K. For determination of the influence of phase composition and surface morphology of these coatings on changes in the corrosion resistance, these coatings were modified in an argon atmosphere by thermal treatment at 873 K for 2h. A scanning electron microscope was used for surface morphology characterization of the coatings. The chemical composition of the coatings was determined by EDS and phase composition investigations were conducted by X-ray diffraction. It was found that the as-deposited coatings consist of a two-phase structure, i.e., iron and silicon. The phase composition for the Fe + Si coatings after thermal treatment is markedly different. The main peaks corresponding to Fe and Si coexist with the new phases: FeSi. Electrochemical corrosion resistance investigations were carried out in 3.5wt% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. On the basis of these investigations it was found that the Fe + Si coatings after thermal treatment are more corrosion resistant in 3.5wt% NaCl solution than the as-deposited coatings. The reasons for this are a reduction in the amount of free iron and silicon, the presence of new phases (in particular silicides), and a decrease of the active surface area of the coatings after thermal treatment.

Characterization of corrosion resistance of Zn-Ni-W and Zn-Ni-P-W heat-treated coatings

2021 ◽  
Vol 25 (3-4) ◽  
pp. 13-17
Author(s):  
Magdalena Popczyk ◽  
Jolanta Niedbała
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Surface Morphology ◽  
Electrochemical Corrosion ◽  
Nacl Solution ◽  
Heat Treated ◽  
Electrochemical Corrosion Resistance

The paper presents results of research concerning the evaluation of corrosion resistance of heat-treated alloy coatings (Zn-Ni-W/320°C and Zn-Ni-P-W/320°C). The surface morphology and phase composition of the obtained coatings were determined. Electrochemical corrosion resistance was studied in 5% NaCl solution. On the basis of these studies it was found that the corrosion resistance of Zn-Ni-P-W/320°C coating is higher than Zn-Ni-W/320°C coating.

EDM performance characteristics and electrochemical corrosion analysis of Co-Cr alloy and duplex stainless steel: A comparative study

2020 ◽  
pp. 095440892097673
Author(s):  
Amit Mahajan ◽  
Gurpreet Singh ◽  
Sandeep Devgan ◽  
Sarabjeet Singh Sidhu
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Duplex Stainless Steel ◽  
Electrode Materials ◽  
Removal Rate ◽  
Electrochemical Corrosion ◽  
Machining Parameters ◽  
Chromium Alloy

Cobalt-chromium alloy (F-90) and duplex stainless steel (DSS-2205) belong to the family of metallic biomaterials, which are frequently used for the manufacture of dental prosthetics, artificial implants including knee and hip joints. This article addresses the investigation highlights of electrical discharge machining (EDM) of Co-Cr alloy and duplex stainless steel using different electrode materials for the evaluation of optimum machining parameters. The samples with superior machining performance and surface integrity were analyzed by electrochemical corrosion testing and found that the EDM treated samples portrayed a notable improvement in the corrosion resistance compared to bare metal. Our results demonstrated that both the substrates i.e. Co-Cr alloy and DSS-2205 were dominantly affected by the intensity of the applied current, and participated in the material removal rate with a contribution of 93.81% (23.37 mm3/min., Co-Cr alloy) and 87.32% (39.76 mm3/min., DSS-2205) respectively. However, the surface roughness of the machined Co-Cr alloy (1.080 µm) was majorly influenced by the current (contribution: 67.24%) and electrode (contribution: 28.27%). Whereas, pulse-on (contribution: 58.37%) and electrode (contribution: 30.52%) were significant for the surface roughness (1.150 µm) of the machined DSS-2205. Moreover, the machined surface also demonstrates the porosity (∼3 to ∼5 µm) and formation of intermetallic oxides, carbon phases on the samples machined at a higher value of current i.e. 16 Ampere. Field emission scanning electron microscopy and X-ray diffractometer were used to scrutinize the surface topography and compositional analysis of the machined substrates. The alternation of the substrate surface observed helpful in enhancing the corrosion resistance of Co-Cr alloy and duplex stainless steel by 80.88% (corrosion rate: 0.00029 mm/year) and 96% (corrosion rate: 0.00763 mm/year), comparative to their respective untreated samples.

Electrochemical corrosion resistance of thermal oxide formed on anodized stainless steel

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hongda Deng ◽  
Yongliang Liu ◽  
Zhen He ◽  
Xiantao Gou ◽  
Yefan Sheng ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Design Methodology ◽  
Electrochemical Corrosion ◽  
Constant Density ◽  
Content Type ◽  
Thermal Oxide ◽  
Pitting Corrosion Resistance ◽  
Dynamic Potential ◽  
Electrochemical Corrosion Resistance

Purpose The purpose of this paper is to investigate and explain thermal oxide effect on electrochemical corrosion resistance anodized stainless steel (SS). Design/methodology/approach Electrochemical corrosion resistance of thermal oxides produced on anodized 304 SS in air at 350°C, 550°C, 750°C and 950°C in 3.5 wt.% NaCl solution have been investigated by dynamic potential polarization, EIS and double-loop dynamic polarization. Anodized 304 SS were obtained by anodization at the constant density of 1.4 mA.cm-2 in the solution containing 28.0 g.L-1H3PO4, 20.0 g.L-1C6H8O7, 200.0 g.L-1H2O2 at 70°C for 50 min. SEM and EDS had been also used to characterize the thermal oxides and passive oxide. Findings Interestingly, anodized 304SS with thermal oxide produced at 350°C displayed more electrochemical corrosion and pitting resistance than anodized 304 SS only with passive oxide, as related to the formation of oxide film with higher chromium to iron ratio. Whereas, anodized 304SS with thermal oxide formed at 950°C shows the worse electrochemical corrosion and pitting resistance among those formed at the high temperatures due to thermal oxide with least compact. Originality/value When thermally oxidized in the range of 350°C–950°C, electrochemical corrosion and pitting corrosion resistance of anodized 304 SS decrease with the increase of temperature due to less compactness, more defects of thermal oxide.

scholarly journals Investigation on Microstructure and Properties of Duplex Stainless Steel Welds by Underwater Laser Welding with Different Shielding Gas

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4774
Author(s):  
Kai Wang ◽  
Changlei Shao ◽  
Xiangdong Jiao ◽  
Jialei Zhu ◽  
Zhihai Cai ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Pitting Corrosion ◽  
Heat Affected Zone ◽  
Shielding Gas ◽  
Pure Nitrogen ◽  
Pitting Corrosion Resistance ◽  
Underwater Laser ◽  
The Impact

Taking S32101 duplex stainless steel as the research object, underwater laser wire filling welding technology was used for U-groove filling welding. The influence of different shielding gas compositions on the ferrite content, microstructure, mechanical properties and pitting corrosion resistance was studied by simulating a water depth of 15 m in the hyperbaric chamber. The results show that, under the same process parameters, the size and proportion of austenite in the weld when using pure nitrogen as the shielding gas are larger than those protected by other shielding gases. In a mixed shielding gas, the increase in nitrogen content has little effect on the strength and toughness of the weld. Regardless of the shielding gas used, the base metal was the weakest part of the weld. At the same time, intermetallic inclusions have an adverse effect on the impact toughness of the weld. The pitting corrosion resistance of the welds depends on the Cr2N content in the heat-affected zone. The precipitation and enrichment of Cr2N causes local chromium deficiency, which is the main factor for the weak pitting corrosion ability of the heat-affected zone. Pure nitrogen protection has a better corrosion resistance than other gas protection.

ZERON 100

Alloy Digest ◽  
1993 ◽  
Vol 42 (11) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Duplex Stainless Steel ◽  
Heat Treating ◽  
Super Duplex Stainless Steel ◽  
Corrosion Performance ◽  
Temperature Performance ◽  
Offshore Oil

Abstract ZERON 100 is a super duplex stainless steel which is manufactured to give a guaranteed corrosion performance by using an equation to control the chemistry in those elements which will determine the corrosion resistance of the material. Major usages in seawater applications, particularly offshore oil gathering systems. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: SS-555. Producer or source: Weir Material Services Ltd.

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