Improved Welding Procedures for Dissimilar Joints

In this section

Back to Core Research Programme AMorph – 4D Printing for Field Morphing Structures Automation of Composite and Hybrid Joining Process Coaxial Wire Additive Manufacturing Processes and In-Line Monitoring Tools Development of Coded Excitation Technique for Non-Metallic Pipes Inspection Development of Digital Twin technology as a demonstrator for real-time integrity assessment of crack growth in tensile specimens Development of Friction Stir Welding (FSW) for Hydrogen Fuel Storage Tanks Development of Leak-Before-Break Hydrogen Storage Composite Pressure Vessels With Polymeric Liner Establishing Assessment Methods for Determining Safe Service Limits of High-Temperature Materials in Extreme Environments Fracture toughness in aggressive environments: effect of crack monitoring techniques on test results In-process detection and non-destructive testing of electron beam weld imperfections Internal Bore Coatings for Applications in Corrosion and Hydrogen Environment Joining of Additively Manufactured Materials Long term behaviour of polymeric liner materials/coatings in hydrogen service Techniques for High Temperature Ultrasonic Inspection of Arc Welding Ultimate Leverage Fund

Project Code: 0902-03

Objectives

Identify welding and heat treatment procedures giving improved resistance of dissimilar metal interfaces to in-service failures.

Project Outline

Welding will be undertaken to provide a series of dissimilar welds for characterisation and validation testing purposes, including welds made using a range of heat inputs to produce a range of interface chemistries. Chemistry and microstructure assessment of the partially mixed zone, as-welded, will be undertaken to provide understanding of the complex microstructure and chemistry of the partially mixed zone, and the effect of welding parameters on the microstructure and chemistry of this particular region.

In addition, PWHT trials will be performed to provide understanding of the effect of PWHT on microstructure and chemistry, particularly carbon diffusion, via electron microprobe analysis and scanning electron microscopy, including EBSD.

A series of environmental tests will be performed to produce data on relative susceptibilities of different joints. Data from current weld practice and the derived optimised weld processes will be generated, to establish the degree of control of performance that can be achieved.

Relevant Industry Sectors

Oil and Gas, Power

Technical and Economic Benefits

Through the development of physically based models capable of predicting the microstructures developed after welding and heat treatment of dissimilar metal joints, considerable savings are possible by minimizing the need for physical testing of new metal combinations and reducing the risk of in-service failure by avoiding microstructures susceptible to cracking in the environments of interest.

The output of the research will provide welding industries with an integrated tool to guide the discovery of new materials and/or process routes to manufacture weld components with improved interface properties which improve their performance, through the choice of appropriate components and an improved tuning of the welding process.