scholarly journals Constitutive Modeling for Prediction of Optimal Process Parameters in Tribo-corrosion Inhibition of Steel Pipes Carrying Fracking Fluid

2021 ◽  
Author(s):  
Jitendra narayan Panda ◽  
Edwin Yanez Orquera ◽  
Brandon Christopher Wong ◽  
Philip Egberts
Keyword(s):  
Wear Rate ◽  
Regression Model ◽  
Corrosion Behavior ◽  
Open Circuit ◽  
Wear Loss ◽  
Total Wear ◽  
Wear And Corrosion ◽  
Geological Formation ◽  
Individual Variables ◽  
The Individual

Abstract The present work examines the effect of three propriety corrosion inhibitors (Dynarate, DWP and CalGuard) on the tribo-corrosion behavior of AISI 4715 steels used to carry fracking liquid from their storage pool to the geological formation. The effect of these three additives on the wear and corrosion behavior of AISI 4715 steel was investigated using a reciprocating tribometer integrated with an open circuit potential electrochemical apparatus. Response Surface Methodology (RSM) was applied to statistically model the effects of various concentrations of Dynarate, DWP andCalGuard on the average coefficient of friction (COF) between the steel and a sapphire counter surface, as well as the total wear loss of the steel due to the combined action of wear-corrosion and inhibition efficiency during sliding. The mathematical regression models were derived from the analysis of variance (ANOVA) techniques. Optimization of the individual variables to minimize the friction and wear responses was estimated using RSM. A full quadratic regression model was established and authenticated before the variables were optimized for different responses. The overall results revealed that Dynarate significantly decreased the COF (0.147) and wear rate (0.3 mm/year) with an inhibitionefficiency of 480% at a concentration of 1%. To investigate the effectiveness of the regression model at predictingthe wear rate, the samples were characterized using 3D optical prolometer and scanning probe microscopy to describe the effect of various additive on the surface morphology of steel. The surface topography measurementsindicated the worn regions for the samples where the Dynarate additive was used was smoother compared with those having the DWP and CalGuard additives. This observation was attributed to the formation of protective lm which limits the transfer of aggressive ions transfer to the steel surface and reduced the total wear loss due to wear and corrosion.

scholarly journals Comparison of Ni-Based Self-Fluxing Remelted Coatings for Wear and Corrosion Applications

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3293
Author(s):  
Norbert Kazamer ◽  
Roxana Muntean ◽  
Petru Cristian Vălean ◽  
Dragoș Toader Pascal ◽  
Gabriela Mărginean ◽  
...  
Keyword(s):  
Wear Rate ◽  
Corrosion Behavior ◽  
Sliding Wear ◽  
Vacuum Furnace ◽  
Controlled Atmosphere ◽  
Corrosion Resistant ◽  
Post Process ◽  
Porosity Reduction ◽  
Wear And Corrosion ◽  
Corrosion Resistant Coatings

The present study investigates the possibility to apply a vacuum furnace thermal post-treatment as an alternative solution for flame sprayed NiCrBSi wear and corrosion-resistant coatings, deposited on a low alloyed structural steel. The controlled atmosphere offers advantages regarding the fusion of the coating, porosity reduction, and degassing. An improvement of the applied heating-cooling cycle was performed through the variation of time and temperature. The best performing samples were selected by comparing their porosity and roughness values. The chosen samples were subsequently characterized regarding their microstructure, microhardness, sliding wear, and corrosion behavior. The experimental work confirms that the use of a vacuum remelting post-process reduces the porosity below 1% and leads to the formation of a larger quantity of hard boron-containing phases, promoting a significant decrease of the wear rate, while maintaining a good corrosion behavior.

Direct and indirect corrosion wear performance of AISI 630 steel for the slipper/swashplate pair in a water hydraulic pump

2019 ◽  
Vol 233 (10) ◽  
pp. 1605-1615
Author(s):  
Liejiang Wei ◽  
Zhenhua Zhang ◽  
Songlin Nie ◽  
Xiangyang Wu
Keyword(s):  
Wear Rate ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Corrosion ◽  
Wear Loss ◽  
Corrosion Wear ◽  
Hydraulic Pump ◽  
Test Analysis ◽  
Wear Performance ◽  
Total Wear ◽  
Water Hydraulic

To explore feasibility of AISI 630 steel applied to slipper/swashplate pair of a water hydraulic pump. Frictional corrosion experiment simulating slipper/swashplate pair operation was systematically conducted under three different lubricating conditions, and the influence of lubricating medium and solution aging on corrosion wear of AISI 630 steel and indirect corrosion wear of its dual PEEK surface were evaluated by means of scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical corrosion test analysis. It was shown that synergistic effect of corrosion and wear played an important role on wear of AISI 630 steel and occupied up to 25% of its total wear loss. Solution aging of AISI 630 steel could help to decrease wear rate of its dual PEEK surface in freshwater, but would significantly increase friction coefficient and wear rate of AISI 630 in seawater and aggravate the wear and indirect corrosion wear of its dual PEEK surface. Therefore, for the water hydraulic slipper/swashplate pair, it is suggested that when taking service in freshwater, solution aging of AISI 630 steel can be considered to alleviate wear of its dual PEEK surface, but when taking service in seawater, solution aging is not recommended, and the original AISI 630 steel is more conducive to obtain preferable friction and wear performance.

Development of a German-Language Questionnaire to Measure Collective Orientation as an Individual Attitude

2017 ◽  
Vol 76 (3) ◽  
pp. 91-105 ◽  
Author(s):  
Vera Hagemann
Keyword(s):  
Team Performance ◽  
Reliability And Validity ◽  
Future Research ◽  
German Language ◽  
Team Members ◽  
Collective Orientation ◽  
Team Research ◽  
German Speaking ◽  
Individual Variables ◽  
The Individual

Abstract. The individual attitudes of every single team member are important for team performance. Studies show that each team member’s collective orientation – that is, propensity to work in a collective manner in team settings – enhances the team’s interdependent teamwork. In the German-speaking countries, there was previously no instrument to measure collective orientation. So, I developed and validated a German-language instrument to measure collective orientation. In three studies (N = 1028), I tested the validity of the instrument in terms of its internal structure and relationships with other variables. The results confirm the reliability and validity of the instrument. The instrument also predicts team performance in terms of interdependent teamwork. I discuss differences in established individual variables in team research and the role of collective orientation in teams. In future research, the instrument can be applied to diagnose teamwork deficiencies and evaluate interventions for developing team members’ collective orientation.

scholarly journals Eight Simple Guidelines for Improved Understanding of Transformations and Nonlinear Effects

2021 ◽  
pp. 109442812199190
Author(s):  
Mikko Rönkkö ◽  
Eero Aalto ◽  
Henni Tenhunen ◽  
Miguel I. Aguirre-Urreta
Keyword(s):  
Generalized Linear Model ◽  
Functional Form ◽  
Nonlinear Models ◽  
Nonlinear Effects ◽  
Recent Past ◽  
Organizational Research ◽  
Common Practices ◽  
Individual Variables ◽  
The Individual ◽  
The Relationship

Transforming variables before analysis or applying a transformation as a part of a generalized linear model are common practices in organizational research. Several methodological articles addressing the topic, either directly or indirectly, have been published in the recent past. In this article, we point out a few misconceptions about transformations and propose a set of eight simple guidelines for addressing them. Our main argument is that transformations should not be chosen based on the nature or distribution of the individual variables but based on the functional form of the relationship between two or more variables that is expected from theory or discovered empirically. Building on a systematic review of six leading management journals, we point to several ways the specification and interpretation of nonlinear models can be improved.

scholarly journals Wear and Corrosion of Cast Al Alloy Piston with and without Brake Oil

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Olawale Olarewaju Ajibola ◽  
Daniel Toyin Oloruntoba
Keyword(s):  
Wear Rate ◽  
Corrosion Rate ◽  
Aqueous Solutions ◽  
Al Alloy ◽  
Material Loss ◽  
Abrasion Test ◽  
Brake Fluid ◽  
Wear And Corrosion ◽  
Aa6061 Aluminium Alloy ◽  
Combined Actions

The effects of wear and corrosion of cast AA6061 aluminium alloy were studied with and without brake fluid using a wear jig while the corrosion rate was determined in brake fluid for 70 days under two experimental set-ups. The tests, yielded 0.00000123 g/mm2/min highest wear rate at 147000 wear cycles and 0.0334 mg/mm2/yr as the highest corrosion rate within the early 39th day of immersion in oil, the values being considered comparatively lower than those obtained for Al alloy in most common wet abrasion test and corrosion in aqueous solutions as previously reported in literature. The material loss rates to wear and corrosion were determined from the equations relating to wear and corrosion based on the ASTM designations. The results show that the combined actions of wear and corrosion contribute to the total loss of piston material immersed in brake oil. This is greater than either of their effects individually on cast Al alloy in the brake oil.

Error Analysis of a Mobile Terrestrial LiDAR System

GEOMATICA ◽  
2014 ◽  
Vol 68 (3) ◽  
pp. 183-194 ◽  
Author(s):  
M. Leslar ◽  
B. Hu ◽  
J.G. Wang
Keyword(s):  
Point Cloud ◽  
Point Clouds ◽  
Sensitivity Study ◽  
Error Sources ◽  
Terrestrial Lidar ◽  
Lever Arm ◽  
Ideal Situation ◽  
Individual Variables ◽  
The Individual ◽  
Source Of Error

The understanding of the effects of error on Mobile Terrestrial LiDAR (MTL) point clouds has not increased with their popularity. In this study, comprehensive error analyses based on error propagation theory and global sensitivity study were carried out to quantitatively describe the effects of various error sources in a MTL system on the point cloud. Two scenarios were envisioned; the first using the uncertainties for measurement and calibration variables that are normally expected for MTL systems as they exist today, and the second using an ideal situation where measurement and calibration values have been well adjusted. It was found that the highest proportion of error in the point cloud can be attributed to the boresight and lever arm parameters for MTL systems calibrated using non-rigours methods. In particular, under a loosely controlled error condition, the LiDAR to INS Z lever arm and the LiDAR to INS roll angle contributed more error in the output point cloud than any other parameter, including the INS position. Under tightly controlled error conditions, the INS position became the dominant source of error in the point cloud. In addition, conditional variance analysis has shown that the majority of the error in a point cloud can be attributed to the individual variables. Errors caused by the interactions between the diverse variables are minimal and can be regarded as insignificant.

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