Menu
Search
Filters
Close
Menu

Save 20% on select best sellers with code MONSTER24 - Shop The Sale Now

Effect of Cyclic Torquing on the Corrosion Resistance and Nut Factor Consistency of Coated High- Strength Steel Bolting

Picture for Effect of Cyclic Torquing on the Corrosion Resistance and Nut Factor Consistency of Coated High- Strength Steel Bolting
Available for download

Almost every piece of equipment and machinery in the Oil and Gas industry requires the use of bolted joints due to numerous advantages that they offer regarding productivity and maintenance however these advantages vanish by inadequate materials selection and installation procedures. Most anti-corrosion coatings applied to bolts do not offer a consistent tightening and they are affected by torqueing during assembly; the nut factor relates the bolt’s installation torque to the tension required to tighten the bolt maintaining a consistent nut factor would solve problems such as over-torquing and corrosion resulting from the coatings peeling-off which may lead to leaking from the joint and even to joint failure. Organic coatings have historically suffered from flaking and peeling when torqued hence metallic coatings such as Ni-Co electroplating may offer a more reliable performance.In order to obtain experimental data comparing the behavior of coatings used in bolted joints simulating service conditions cyclic torquing (up to 5 cycles) was applied to fasteners with different coatings and the nut factor and corrosion resistance was evaluated. The tested samples were B7M ASTM A193/A193M bolts and 2HM ASTM A194/A194M nuts with the following coating conditions: 1) No coating 2) Ni-Co Electroplating 3) zinc undercoat with PTFE topcoat and 4) TSA / PTFE. All samples were tested with dry runs (no lubricant) and two different commercial lubricants. A Skidmore-Wilhelm load cell was used to apply the cyclic torquing and to calculate the nut factor on each cycle. Corrosion tests were performed before and after torquing following ASTM G59 standard and environmental exposure following ASTM B368 standard to evaluate the materials corrosion resistance without torque. Ni-Co electroplating showed a better performance compared to the other tested coatings it offered the highest nut factor consistency and the lowest corrosion rate after the cyclic torqueing and after environmental exposure.The main impact of this work is providing consistent and reliable test data about nut factor and corrosion resistance of coatings; this data can be used to compare available coated fasteners for selection of the best solution for bolting in oilfield and industrial application. Ni-Co electroplating is featured as a coating that provides corrosion resistance and nut factor consistency regardless the number of assembly/disassembly cycles it is proposed as a solution to avoid joint leaking and likely catastrophic failures.

Product Number: 51319-13268-SG
Author: Omar Rosas-Camacho
Publication Date: 2019
$0.00
$20.00
$20.00
Also Purchased
Picture for Evaluation of Test Techniques for Determining Susceptibility Nickel Based Alloys to Hydrogen Assiste
Available for download

51316-7828-Evaluation of Test Techniques for Determining Susceptibility Nickel Based Alloys to Hydrogen Assisted Cracking in Seawater with CP Conditions

Product Number: 51316-7828-SG
ISBN: 7828 2016 CP
Author: Brandon Rollins
Publication Date: 2016
$20.00
Picture for Probabilistic Performance Assessment of Bolts Used in Oil and Gas Drilling and Production Systems
Available for download

51318-10524-Probabilistic Performance Assessment of Bolts Used in Oil and Gas Drilling and Production Systems

Product Number: 51318-10524-SG
Author: Narasi Sridhar / Ramgopal Thodla / Christopher Taylor
Publication Date: 2018
$20.00

The effect of the combined uncertainties on the performance of bolts in drilling and production systems using a Bayesian probabilistic approach.  Also - managing the performance of bolts.
Picture for Hydrogen Embrittlement of ASTM A320 L7 & L43 Grade Carbon Alloy Steel Bolts in Subsea Environments
Available for download

Hydrogen Embrittlement of ASTM A320 L7 & L43 Grade Carbon Alloy Steel Bolts in Subsea Environments

Product Number: 51319-12785-SG
Author: Herman Amaya
Publication Date: 2019
$20.00

This paper reports an approach towards studying the susceptibility of materials to hydrogen embrittlement of several yield strength levels of ASTM A320 L7 & L43 grade carbon alloy material used for bolting . The test method used is based on ASTM E1820 using pre-cracked compact tension (CT) specimens in a seawater environment and under cathodic protection. The procedure has been to monitor the crack growth and the crack growth rate (CGR) at various constant stress intensity (K-levels) and at varying cathodic protection potentials. In this way these two parameters can be seen as representative of the susceptibility to embrittlement cracking of the materials at the specific stress intensity levels and as a function of the varying CP levels.The results indicate the strong effect that both stress intensity K-values and applied potential have on crack growth rates in environment and on the resulting susceptibility of the material to embrittlement. On the practical operational level the results also highlight the importance of actively monitoring and controlling cathodic protection (CP) potential levels as a means of increasing the allowable margin of error of the intersection between material quality design factors and the effect of the challenging environments of Oil & Gas subsea drilling and production operations.
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support