Solid State Joining of Creep Enhanced Ferritic Steels


Flat plate friction stir welds in HSLA65 plate, stay flat!
Flat plate friction stir welds in HSLA65 plate, stay flat!
Pacific Northwest National Laboratory (PNNL)
Website:  PNNL - Pacific Northwest National Laboratory
Award Number:  FWP-66059
Project Duration:  10/01/2014 – 09/30/2018
Total Award Value:  $1,075,000
DOE Share:  $1,075,000
Performer Share:  $0
Technology Area:  Plant Optimization Technologies
Key Technology:  High Performance Materials
Location:  Richland, Washington

Project Description

The goal of this project is to develop an alternative solid state joining technology, Friction Stir Welding (FSW), which can enable higher performance from Creep Strength Enhanced Ferritic (CSEF) steels, anticipated to be used in advanced ultrasupercritical (AUSC) coal-fired power plants. A primary problem in the high temperature application of welded CSEF steels is that the welds of these steels fail (Type IV cracking) at a creep life far below that of the base metal. This has led to a reduced performance - either a reduced calculation of strength and lifetime for assemblies made from these alloys, or the use of expensive post weld heat treatment procedures to recover base metal creep strength in the weldment. Previous work at PNNL on the NETL funded project. "Joining of Advanced High-Temperature Materials", showed that a new joining process, FSW, has the ability to produce welds in Grade 91M CSEF plate that have significantly improved creep performance over equivalent fusion welds.

Project Benefits

This project is expected to generate pertinent creep-fatigue data and develop new lifetime models that will allow accurate prediction of the lifetimes of those fossil fuel power plant components that are subjected to flexible operation (e.g., load cycle following of renewable power generation). Improvements to creep-fatigue data and lifetime models may advance the development of advanced power plant designs that will lead to improvements in efficiency and operational flexibility resulting in lower operating costs.

Contact Information

Federal Project Manager 
Vito Cedro:
Technology Manager 
Briggs White:
Principal Investigator 
Glenn Grant:

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