Cost-Effective Techniques for Weld Property Measurement and Technologies for Improving Weld HE and IGSCC Resistance for Alternative Fuel Pipelines

Main Objective

Built upon proven technologies, this proposal research aims at (i) advancing the general knowledge related to fatigue and fracture properties of pipeline steel welds subject to high pressure hydrogen atmosphere and (ii) developing technologies for weld property improvement.

• Apply Multiple-Notch Tensile and Spiral Notch Torsion Tests for measuring the local tensile strength and fracture toughness of weld region in high-pressure hydrogen.
• Develop a cost-effective low-frequency cyclic fatigue testing technique for measuring the weld fatigue property in high-pressure hydrogen.
• Develop the technical basis and database of hydrogen-induced degradation of weld mechanical properties as a function of pressure, temperature and microstructure.
• Evaluate technologies for improving the HE and IGSCC resistance of steel welds. The technologies include (1) tailoring residual stress by overlay welds, (2) new welding consumables, and (3) friction stir welding.

Public Abstract

Comprehensive knowledge of mechanical properties of pipeline steels in high-pressure hydrogen is essential for the structural integrity of a pressurized hydrogen transport system. This project focuses on obtaining much needed data on fracture toughness and fatigue life for weld regions. For testing of weld regions, cost-effective testing techniques developed in previous federal-funded programs will be further refined and applied to investigate the effects of pressure and temperature on the degradation of weld fracture toughness in high-pressure hydrogen. A novel cost-effective low-frequency fatigue test apparatus will be developed to determine the weld fatigue life under realistic in-service cyclic loading frequencies of hydrogen pipelines. These property data will be critical to support industry consensus standards for hydrogen transport via pipeline, and to support the design and maintenance operation by pipeline operators. In addition, advanced welding techniques will be demonstrated to control the weld residual stress and to tailor the weld microstructure for improving weld resistance to HE and IGSCC.

Final Report

Final Report 1231 7

Final_Report_1231_7.pdf (6,235,680 bytes) [View] [Download/Save...]

Technical Reports and Documents

Paper presented titled "MICROSTRUCTURE AND MECHANICAL PROPERTY PERFORMANCE EVALUATION OF COMMERCIAL GRADE API PIPELINE STEELS IN HIGH PRESSURE GASEOUS HYDROGEN"

Stalheim_-_Microstructure_and_Mechanical_Prop_in_Gaseous_Hydrogen_-_Final_Manuscript.pdf (401,627 bytes) [View] [Download/Save...]

Paper titled "Design Analysis of steel concrete composite vessel for Stationary Storage of High-Pressure Hydrogen

design_analysis_of_steel.pdf (523,983 bytes) [View] [Download/Save...]

Other Files

2007 NACE paper on hydrogen

NACE_Corrosion_2007_Paper_No__07493.pdf (10,414,893 bytes) [View] [Download/Save...]

Project status presentation on weld propertys research October 2012

Weld_Property_in_H2_-_Oct2012_Update.pdf (975,553 bytes) [View] [Download/Save...]