Alert: Export Control Check Required
Thank you for requesting a TWI Industrial Members Report.
To meet UK government requirements, your request will undergo an Export Control Check. This process reviews the technical content of the report, identifies the end user, and addresses any concerns.
Please submit your request to CRP@twi.co.uk including your name, member company that you work for and your location. We will contact you regarding the request within 2 working days and any additional information required to complete the necessary checks.
We look forward to receiving your request and processing it through our export control procedure.
Thank you,
TWI CRP Operations Team
This content is only available to Industrial Members, Find out how to become a Member of TWI.
TWI Industrial Member Report Summary 590/1997
G Ferguson
Heat input limits are imposed for the welding of large steel structures since use of high arc energies results in slower cooling rates, which may adversely affect both weld metal and heat affected zone (HAZ) properties. In the HAZ, the deterioration in mechanical properties, in particular toughness, arises partly from increased grain coarsening.
Background
A review of previous work carried out on the effect of Ti-containing particles on the HAZ microstructure and toughness properties of steels has been carried out. In addition, a series of bead-in-groove test welds using arc energies in the range 1-9 kJ/mm, have been carried out on steels supplied by several steelmakers as being suitable for high heat input welding in order to investigate the effect of heat input on the HAZ grain size and microstructure. Transmission electron microscopy was used to characterise the second phase particles in the parent steels and in the HAZs in order to identify their role with respect to HAZ grain coarsening and microstructure. HAZ toughness testing was carried out using 9 kJ/mm heat input multipass butt welds made from the steels showing the most promising HAZ characteristics, in terms of both grain coarsening behaviour and microstructural development.
Objectives
- To identify which particles are effective in restricting grain growth and nucleating ferrite, and to identify which characteristics of the particles control their effectiveness.