Optimizing Weld Integrity for X80 and X100 Linepipe

Overview

Fast Facts
Project No.	152
Contract No.	DTRS56-04-T-0011
Research Award Recipient	Edison Welding Institute, Inc. 1250 Arthur E. Adams Dr. Columbus, OH 43221-3560
AOTR	Frank Licari
Researcher Contact Info	Mr. Bill Bruce, EWI 1250 Arthur E. Adams Dr, Columbus, OH, 43221 Ph (614) 688-5188 Fax (614) 688-5001 Email william_bruce@ewi.org
Peer Review	More than Effective

Financial and Status Data
Project Status	Closed
Start Fiscal Year	2005 (10/05/2004)
End Fiscal Year	2007 (07/06/2007)
PHMSA $$ Budgeted	$311,387.48

Main Objective

The major objectives of this program are as follows:

To provide a better understanding of the factors that control strength and toughness in high strength girth welds.
To develop optimized welding consumables and welding procedures for high strength pipelines.
To develop best practice guidelines for the welding of high strength pipelines.
To disseminate best practice information to the pipeline industry.
To enable high integrity girth welds to be more reliably and economically achieved in high strength pipelines.

Public Abstract

This project will provide a better understanding of the factors that control strength and toughness in high strength girth welds and will enable high integrity girth welds to be more reliably and economically achieved in high strength pipelines. Reducing the cost of new pipelines is a major driving force within the pipeline industry and the use of high strength steels offers major cost benefits for long distance gas transmission pipelines. The move towards higher strength steels also comes at a time when design practices are evolving and there is greater focus on overmatching criteria for pipeline girth welds. In the case of X80 and X100 pipe, this leads to minimum weld metal tensile requirements of 100ksi and 120ksi while still maintaining high toughness and CTOD properties. One of the major challenges in high strength pipeline construction is producing girth welds that both overmatch the tensile properties of the parent pipe and also exhibit excellent toughness. Previous work has demonstrated that it can be difficult to achieve the optimum combination of tensile and toughness properties using commercially available welding consumables and that weld metal properties are very susceptible to process variables. The objectives of this proposed project are to review the current status of X80 and X100 pipeline welding technology and to examine the trend towards overmatching weld metals. A best practice guide will be developed for X80 welding based on existing commercially available welding technology and optimized welding consumables and procedures will be developed for X100 pipelines.

The project team is made up of the following organizations:

EWI - The largest Welding and Materials Joining Technology Center in North America Cranfield University - A leading provider of state-of-the-art pipeline welding technology EWI Microalloying - An internationally recognized materials consulting company. CANMET - a laboratory of the Canadian federal government and Canada's leading research facility in welding and pipeline integrity. El Paso Pipeline Group - The first U.S. operator to design and construct a major X80 gas transmission pipeline (Cheyenne Plains Pipeline). TransCanada Pipelines - The largest gas pipeline transmission company in Canada. Miller Electric Manufacturing Company – A leading developer and supplier of state of the art welding equipment and accessories for pipeline welding. Hobart Brothers Company – A leading developer of state of the art welding consumables with a strong emphasis on pipeline welding and construction. PRCI - An international consortium of pipeline companies.