Harendra Kumar

Student Name

Harendra Kumar

Research Title

An integrated approach for detection of subsurface microscopic damage in steel

Keywords

Type IV creep, HTHA, ultrasonic, P91 steel

Sponsor

TWI

Affiliated University

Brunel University London

Supervisors

Dr Channa Nageswaran (TWI Ltd.), Prof Hari Babu Nadendla and Prof Tat-Hean Gan (Brunel University London)

Start Date

May 2016

Project Outline

This PhD is aligned with core research at TWI on early detection of creep damage in creep strength enhanced ferritic (CSEF) steels. A number of premature failures of welded CSEF steel components have been reported in power industry. Failure analysis indicates Type IV creep to be the dominant failure mechanism. Type IV creep incubates subsurface in the form of creep voids which accumulates for a significant portion of creep life of a component. Subsequently these void coalesces under stress and results in sudden failure with no detectable warning sign on the surface. At present there is no reliable field deployable technique for assessment of such degradation. This research aims at developing and validating a highly sensitive ultrasonic technique enabling reliable assessment of Type IV creep at an early stage. Positive outcome of this research may be a step towards unification of Type IV creep monitoring and assessment approach in power plants globally.

Publications

Towards a viable field deployable ultrasonic technique for detection of Type IV creep damage in CSEF steels at an early stage; Harendra Kumar, Jack W. Lambert, Channa Nageswaran, Hari Babu Nadendla and Tat-Hean Gan; ASME  pressure vessels & piping conference 2019, San Antonio, Texas, USA

https://doi.org/10.1115/PVP2019-93692

Detection of early-stage creep damage in welded steels; Harendra Kumar, Jack Lambert and Channa Nageswaran

https://www.twi-global.com/what-we-do/research-and-technology/research-reports/industrial-member-reports/early-stage-creep-in-csef-steels-1113-2019