Microstructural and property assessment of creep aged 12cr steel after welding

The electricity public utility of Eskom (South Africa) has an ageing fleet of power generation equipment and due to shortage of capacity there is limited time for maintenance and replacements. Complete main steam pipework replacements are not practical and in many instances selective welding must be done on creep aged and sometimes creep damaged material. The question arises whether these repair welds damage the components to an unacceptable degree or not, and a complete replacement can be avoided. This work aims at studying the effect of the welding process on the damage state of the material on the example of the widely used X20 steel and advising Eskom on the weldability limits of this steel. Real welds consisting of new and creep aged steel were prepared and characterised. Furthermore, the heat input was simulated in additional samples using Gleeble thermomechanical equipment.

Grantor dc:publisher.institution

Centre for Materials Engineering

Year dc:date.issued

2013

Author dc:creator

• Molokwane, Teboho Jacob

Advisors dc:contributor.advisor

• Sonderegger, B
• Knutsen, Robert D

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/8678

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/8678