scholarly journals Evaluation of environmental friendly Ag-PTFE composite coating for use in threaded compression fittings

2017 ◽  
Vol 232 (5) ◽  
pp. 503-512 ◽  
Author(s):  
Raymond Sieh ◽  
Huirong Le
Keyword(s):  
Stainless Steel ◽  
Solid Lubricant ◽  
Composite Coatings ◽  
Operating Conditions ◽  
Vacuum System ◽  
Environmental Friendly ◽  
Potential Risks ◽  
Fluid Transfer ◽  
Electroplating Process ◽  
Torque Angle

Threaded tubular fittings are used in a wide variety of industries for critical applications involving fluid transfer in a pressurised or vacuum system. These fittings are made of corrosion resistant metals such as stainless steel which are desirable in corrosive operating conditions; however, stainless steel is prone to galling which can cause threads to seize, resulting in loss of productivity. To prevent this, threads are electroplated using silver (Ag) coatings which prevent galling and serve as a solid lubricant during the connection make-up process. The Ag cyanide electroplating process currently used in industry is both hazardous to human health and its wastes are detrimental to the environment. The objective of this work is to evaluate environmental friendly self-lubricating Ag and Ag-polytetrafluoroethylene composite coatings using a non-cyanide electroplating process against the commercially available cyanide Ag coating through the analysis of torque-angle signatures and the torque-angle slope which characterises the make-up process. Results from the experiments suggest that the non-cyanide Ag-polytetrafluoroethylene coating is a potentially viable replacement option. Investigation and analysis of the coating performance have also highlighted potential risks of failure through poor lubrication during the make-up process and suggestions for improving the make-up process.

High temperature friction and wear properties of graphene oxide/polytetrafluoroethylene composite coatings deposited on stainless steel

RSC Advances ◽  
2016 ◽  
Vol 6 (7) ◽  
pp. 5977-5987 ◽  
Author(s):  
N. Nemati ◽  
M. Emamy ◽  
S. Yau ◽  
J.-K. Kim ◽  
D.-E. Kim
Keyword(s):  
Stainless Steel ◽  
Graphene Oxide ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Composite Coatings ◽  
Friction Material ◽  
Wear Properties ◽  
Low Friction ◽  
Solid Lubricant Coating ◽  
Friction And Wear Properties

Polytetrafluoroethylene (PTFE) coating is known as a low friction material that is often used as a solid lubricant coating.

Adaptive Solid Lubricant Transfer Films for Conductivity and Oxidation Control

2012 ◽  
Author(s):  
Patrick S. M. Dougherty ◽  
Cecily M. Sunday ◽  
C. Fred Higgs
Keyword(s):  
Solid Lubricant ◽  
Composite Coatings ◽  
Solid Lubricants ◽  
Operating Conditions ◽  
Low Friction ◽  
Composite Powders ◽  
Electrically Conductive ◽  
Transfer Films ◽  
Oxidation Resistant ◽  
Complex Deposition

The success of solid lubricants to exhibit ultra-low friction and wear behaviors in oil-prohibiting environments, has led to a major effort to optimize their performance and enhance their applicability. Depending on the operating conditions, solid lubricants may take on a plethora of forms including fabricated composite coatings, thick-film powder lubricants, nano-particle additives for hard surfaces or liquid lubricants, and self-replenishing transfer films. One of the benefits of transfer films are their freedom from the complex deposition techniques required for most other solid lubricant systems. In this work, the potential for adaptive self-replenishing transfer films was explored by creating composite powders of well-known powder lubricants and electrically conductive or anti-oxidation materials. MoS2, WS2, and Graphite Powders were mixed in varying composition with Cu, Sb2O3, and BO3 additives and compacted to form “tuned” or adaptive powder pellets. Relationships between friction, wear, electrical resistance, tribo-induced oxidation and powder composition, will be presented in order to investigate the potential of composite property optimization for lubricious, highly conductive, and oxidation resistant transfer films.

REMANIT 4306

Alloy Digest ◽  
1997 ◽  
Vol 46 (4) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Austenitic Stainless Steel ◽  
Cold Working ◽  
Heat Treating ◽  
Operating Conditions ◽  
Low Carbon ◽  
Corrosion Resistant ◽  
Temperature Performance

Abstract Remanit 4306 is a low-carbon chromium nickel austenitic stainless steel that is superior in corrosion resistance to type 302 (see Alloy Digest SS-99, revised September 1998). Due to its low carbon content, Remanit 4306 is intergranular corrosion resistant under continuous operating conditions up to 350 C (652 F). This grade is particular suitable for high degrees of cold working and for sequential drawing. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-679. Producer or source: Thyssen Stahl AG.

Alginate/Bioglass® composite coatings on stainless steel deposited by direct current and alternating current electrophoretic deposition

2013 ◽  
Vol 233 ◽  
pp. 49-56 ◽  
Author(s):  
Qiang Chen ◽  
Luis Cordero-Arias ◽  
Judith A. Roether ◽  
Sandra Cabanas-Polo ◽  
Sannakaisa Virtanen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Electrophoretic Deposition ◽  
Direct Current ◽  
Composite Coatings ◽  
Alternating Current

The Resistive Properties of Proton Exchange Membrane Fuel Cells With Stainless Steel Bipolar Plates

2010 ◽  
Vol 7 (4) ◽  
Author(s):  
Shuo-Jen Lee ◽  
Kung-Ting Yang ◽  
Yu-Ming Lee ◽  
Chi-Yuan Lee
Keyword(s):  
Stainless Steel ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Single Cells ◽  
Operating Conditions ◽  
Pure Oxygen ◽  
Bipolar Plates ◽  
Transfer Resistance ◽  
Treated Cell ◽  
Ohmic Resistance

In this research, electrochemical impedance spectroscopy is employed to monitor the resistance of a fuel cell during operation with different operating conditions and different materials for the bipolar plates. The operating condition variables are cell humidity, pure oxygen or air as oxidizer, and current density. Three groups of single cells were tested: a graphite cell, a stainless steel cell (treated and original), and a thin, small, treated stainless steel cell. A treated cell here means using an electrochemical treatment to improve bipolar plate anticorrosion capability. From the results, the ohmic resistance of a fully humidified treated stainless steel fuel cell is 0.28 Ω cm2. Under the same operating conditions, the ohmic resistance of the graphite and the original fuel cell are each 0.1 Ω cm2 and that of the small treated cell is 0.3 Ω cm2. Cell humidity has a greater influence on resistance than does the choice of oxidizer; furthermore, resistance variation due to humidity effects is more serious with air support. From the above results, fuel cells fundamental phenomenon such as ohmic resistance, charge transfer resistance, and mass transport resistance under different operating conditions could be evaluated.

scholarly journals Laser Cladding of Ni-Co-W Composite Coating on Stainless Steel to Enhance Wear Resistance

2021 ◽  
Author(s):  
Linlin ZHANG ◽  
Dawei ZHANG
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Eutectic Structure ◽  
Wear Properties ◽  
Fine Grained ◽  
Noticeable Improvement ◽  
Enhance Wear Resistance

Ni-Co-W composite coatings modified by different contents of Co-based alloy powder in the Ni-based alloy with 35 wt.% WC (Ni35WC) were deposited on stainless steel by laser cladding. The influence of compositional and microstructural modification on the wear properties has been comparatively investigated by XRD, SEM, and EDS techniques. It was found that the austenite dendrites in the modified coating adding 50 wt.% Co-based alloy were refined and a lot of Cr23C6 or M23(C, B)6 compounds with fine lamellar feature were formed around austenitic grain boundaries or in the intergranular regions. The contribution of element Co to the modification of Ni35WC coating is that it cannot only promote the formation of more hard compounds to refine austenite grains, but also refine the size of precipitates, and change the phase type of eutectic structure as a result of disappeared Cr boride brittle phases. A noticeable improvement in wear resistance is obtained in the Ni35WC coating with 50 wt.% Co-based alloy, which makes the wear rate decreased by about 53 % and 30% by comparison to that of the substrate and the Ni35WC coating, respectively. It is suggested that the improvement is closely related to the composite coating being strengthened owing to the increase of coating hardness, formation of a fine-grained microstructure caused by Co, and fine hard precipitate phases in the eutectic structure.

scholarly journals Enhanced Mechanical and Tribological Capabilities of a Silicon Aluminum Alloy with an Electroplated Ni–Co–P/Si3N4 Composite Coating

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Zhijie Li ◽  
Fei Ma ◽  
Dongshan Li ◽  
Shanhong Wan ◽  
Gewen Yi ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Composite Coating ◽  
Composite Coatings ◽  
Engine Oil ◽  
Si Substrate ◽  
Wear Performance ◽  
Cobalt Layer ◽  
Hard Chrome ◽  
Electroplating Process ◽  
Hardness Values

Ni–Co–P/Si3N4 composite coatings were fabricated over an aluminum–silicon (Al–Si) substrate using a pulse-current electroplating process, in which the rapid deposition of an intermediate nickel–cobalt layer was used to improve coating adhesion. The microstructure, mechanical, and tribological behaviors of the electroplated Ni–Co–P/Si3N4 composite coating were characterized and evaluated. The results revealed that the electroplated Ni–Co–P/Si3N4 composite coating primarily consisted of highly crystalline Ni–Co sosoloid and P, and a volumetric concentration of 7.65% Si3N4. The electroplated Ni–Co–P/Si3N4 composite coating exhibited hardness values almost two times higher than the uncoated Al–Si substrate, which was comparable to hard chrome coatings. Under lubricated and dry sliding conditions, the electroplated Ni–Co–P/Si3N4 composite coating showed excellent anti-wear performance. Whether dry or lubricated with PAO and engine oil, the composite coating showed minimum abrasive wear compared to the severe adhesive wear and abrasive wear observed in the Al–Si substrate.

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