Abstract

BULBRING, D.L.H.; HATTINGH, D.G.; BOTES, A.  and  ODENDAAL, D.H.. Friction Hydro Pillar Process as an alternative repair technology for creep evaluation sites on thick-walled 10CrMo910 creep-resistant steel structures. J. S. Afr. Inst. Min. Metall. [online]. 2013, vol.113, n.2, pp.129-136. ISSN 2411-9717.

The removal of a cylindrical core from thick-wall sections for creep analysis by the relatively new Weldcore^® process represents a very exciting methodology for obtaining more representative creep damage data from large engineering structures. The cylindrical core that is removed, representing about 60% of the wall thickness, leaves a substantial removal site that needs to be repaired. This paper presents data pertaining to taper Friction Hydro Pillar Processing as an alternative repair technique for filling the core removal site. Process parameters were evaluated with special attention being paid to the effect of downward force on process response variables, weld defects, and mechanical properties of 10CrMo910 steel. Process temperature and torque response as well as total process energy input were also considered. This paper also assesses the static and dynamic performance of this repair technique. The influence of a varying downward force and the occurrence and position of discontinuities were quantified. Downward force was shown to have the most notable effect on weld joint dynamic performance and was found to be related to the process temperatures achieved in close proximity to the weld interface.

Keywords : friction hydro pillar processing; coring; creep damage; welding; downward force.

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