Session: 05-02-4: Experimental Testing - Session four

Paper Number: 133981

133981 - What Are My Options? Review of Non-Destructive Mechanical Tests for Steel Linepipe Yield Strength 

Abstract: 

The prospect of eliminating destructive tensile testing for line pipe steel is tantalizing. For over 100 years, researchers have explored methods utilizing material deformation responses to concentrated loads from small indenters for assessing key material characteristics, including yield strength, ultimate tensile strength, toughness, and ductility. From Brinell's correlation of hardness to ultimate tensile strength in 1900 to Tabor's identification of the 3:1 ratio of mean contact pressure to uniaxial yield stress in 1950, and the evolution to contemporary techniques such as Instrumented Indentation Testing (IIT), Hardness, Strength, and Ductility (HSD), and Profilometry-based Indentation Plastometry (PIP), the question arises: have we arrived at the definitive nondestructive method for identifying steel yield strength?

This presentation delves into the merits and drawbacks of indentation-based approaches, and other approaches, for the non-destructive estimation of line pipe steel yield strength. Methods for non-destructive estimation of steel linepipe yield strength yield strength are surveyed, recognizing that yield strength is important for grade estimation. Operators seek rapid, accurate, precise, reliable, and repeatable non-destructive testing methods to estimate pipe yield strength as part of the process to determine Maximum Allowable Operating Pressure (MAOP), burst pressure, and to perform other critical calculations. We provide a description of several methods to estimate steel linepipe yield strength, including conventional hardness tests such as ultrasonic contact impedance (UCI), and portable Rockwell testing. Then recently developed tests to directly estimate YS and ultimate tensile strength (UTS) are discussed, including Instrumented Indentation Testing (IIT), Hardness, Strength, and Ductility (HSD), and Profilometry-based Indentation Plastometry (PIP). One approach for estimating strength based on composition and microstructure alone (PRCI’s Checkmate) is also discussed. For each method the discussion includes the mechanism (working principle), logistics, dimensional considerations, potential pitfalls, and example models. By offering a thorough overview, we aim to assist operators in identifying the most suitable non-destructive test for their specific requirements.

This presentation explores the mechanisms of deformation, the damage (indentation) left behind, the measurements taken, and the correlations or first principles calculations applied by each test. A brief portion of the talk will also be used to address test logistics, test duration, and test preparation requirements. By offering an educational perspective, this talk aims to assist operators in evaluating the most suitable non-destructive test for their specific requirements.

Presenting Author: Nathaniel Switzner RSI Pipeline Solutions

Presenting Author Biography: Nathaniel Switzner is a metallurgical engineering consultant with RSI Pipeline Solutions and an Assistant Professor in the Mechanical Engineering Department at American University of Iraq-Sulaimani. His research focuses on the practical implications of the microstructure and mechanical properties of steel and other metal alloys.

Authors:

Nathaniel Switzner RSI Pipeline Solutions
Bill Amend RSI Pipeline Solutions
Peter Martin RSI Pipeline Solutions
Joel Anderson RSI Pipeline Solutions