Menu
Search
Filters
Close
Menu

Celebrate World Corrosion Awareness Day with 20% off eCourses and eBooks with code WCAD2024 at checkout!

Finite Element Analysis to Locate Maximum Values of the First and Second Principal Strains in the Tensile Pull-Off Test for Coating Adhesion on Large Pipes

Picture for Finite Element Analysis to Locate Maximum Values of the First and Second Principal Strains in the Tensile Pull-Off Test for Coating Adhesion on Large Pipes
Available for download

The tensile pull-off test, as in ASTM 4541, in which a round metal ‘dolly’ is glued to a coating then pulled off is a very common method for measuring adhesion of a coating to its substrate. This technique is very well known to produce joint failures that are not at the intended coating steel interface but may initiate within the coating, within the glue or at the glue-coating interface. 

Product Number: 41214-814-SG
Author: S. G. Croll, C. Siripirom, B. D. Keil
Publication Date: 2014
Industries: Pipelines, Tanks, and Underground Systems , Coatings
$0.00
$20.00
$20.00

The tensile pull-off test, as in ASTM 4541, in which a round metal ‘dolly’ is glued to a coating then pulled off is a very common method for measuring adhesion of a coating to its substrate. This technique is very well known to produce joint failures that are not at the intended coating steel interface but may initiate within the coating, within the glue or at the glue-coating interface. It also provides results that are very inconsistent in magnitude. Nevertheless, the method is used as a quality assurance procedure to evaluate the surface treatment of a steel pipe substrate and the subsequent coating application in order to assure the likely corrosion protection that the coating might provide for the pipe. This seemingly simple test is affected by many experimental and material variables. The joint will fail, and the strength be measured, in the material that suffers the most deformation. Determinations were made of the Young’s modulus and Poisson’s ratio of three coating materials, two glues and the metal dolly and substrate. Then finite element calculations were made of the stresses and strains in the coating and the dolly glue. These simple calculations show how differences in mechanical properties between glue and coating, substrate curvature and misalignment of the dolly, may determine which part of the adhesive joint suffers the most deformation and thus determines the locus of failure. Adhesion test failure modes found in practice are very consistent with the results of these calculations.

The tensile pull-off test, as in ASTM 4541, in which a round metal ‘dolly’ is glued to a coating then pulled off is a very common method for measuring adhesion of a coating to its substrate. This technique is very well known to produce joint failures that are not at the intended coating steel interface but may initiate within the coating, within the glue or at the glue-coating interface. It also provides results that are very inconsistent in magnitude. Nevertheless, the method is used as a quality assurance procedure to evaluate the surface treatment of a steel pipe substrate and the subsequent coating application in order to assure the likely corrosion protection that the coating might provide for the pipe. This seemingly simple test is affected by many experimental and material variables. The joint will fail, and the strength be measured, in the material that suffers the most deformation. Determinations were made of the Young’s modulus and Poisson’s ratio of three coating materials, two glues and the metal dolly and substrate. Then finite element calculations were made of the stresses and strains in the coating and the dolly glue. These simple calculations show how differences in mechanical properties between glue and coating, substrate curvature and misalignment of the dolly, may determine which part of the adhesive joint suffers the most deformation and thus determines the locus of failure. Adhesion test failure modes found in practice are very consistent with the results of these calculations.

Product tags
Also Purchased
Adhesion Measurements of Coatings on Cylindrical Steel Pipes: Variability & Significance
Available for download

Adhesion Measurements of Coatings on Cylindrical Steel Pipes: Variability & Significance

Product Number: 41214-815-SG
Author: S. G. Croll, B. D. Keil
Publication Date: 2014
$20.00

Quality assurance of coatings on steel water pipes commonly relies on tensile pull-off measurements of the coating-steel adhesion, according to ASTM D4541. These tests are performed by adhering a metal ‘dolly’ to the coating with an adhesive, then scoring around the dolly circumference, through the coating down to the steel surface, before recording the stress necessary to pull the dolly (and coating) away from the steel pipe. 
Field and Laboratory Experience with Polyurethane Pipe Linings
Available for download

Field and Laboratory Experience with Polyurethane Pipe Linings

Product Number: 41214-863-SG
Author: Allen Skaja, David Tordonato, Bobbi Jo Merten
Publication Date: 2014
$20.00

The Bureau of Reclamation’s Materials Engineering Research Laboratory has been evaluating polyurethane pipe linings for severe immersion exposure, specifically for outlet works and penstock linings. Polyurethanes have several advantages over other coatings, such as application temperature range, faster cure times in cold temperatures, rapid return to service, coat large surface area rapidly, low viscosity (i.e., accommodates pumping over longer distances), and greater impact resistance. 
Pull-Off Adhesion Testing of Coatings - Improve Your Technique
Available for download

Pull-Off Adhesion Testing of Coatings - Improve Your Technique

Product Number: 41215-893-SG
Author: JF Fletcher, DJ Barnes
Publication Date: 2015
$20.00

Pull-off adhesion testing is widely used to assess the protective coating process. It is also used to determine if a coating is fit for service in new construction and for repairs to existing structures. The result is often critical to the acceptance or rejection of a coating process, as the adhesion value quoted by the paint manufacturer can be adversely affected by aspects of the coating process. Low adhesion values are indicative of premature failure of the coating and are often due to inadequate surface preparation of the substrate. 
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