Best of Schadensanalyse an Turbomaschinen – die Highlights aus 20 Jahren LaborpraxisMittwoch (21.09.2016) 15:40 - 16:10 Uhr Hörsaal A Bestandteil von:
In this contribution, the most interesting and educating failure cases are presented that the author came across during his some twenty years of laboratory practice as manager of the Materials Testing Laboratory of the Berlin Gas Turbine Plant of Siemens’ Power and Gas Division. The case studies are presented and categorised in accordance with VDI Guideline 3822, the German failure analyst’s guide to the subject of how to organise and run a root cause failure analysis. An effort was made to have each of the main four categories of failure causes represented, namely failures due to mechanical loading, corrosive failures, failures due to thermal loading, and tribological failures. Case studies include turbomachinery components that failed due to tensile overload, stress corrosion cracking, intergranular corrosion, hydrogen embrittlement, hot cracking, fretting, erosion, and galling. Affected components include valves, retaining rings, tubing and piping, burners, rotor disks, lifting lugs, and casings. Some of the presented cases were published in the new section “Failure Analysis” of Practical Metallography between October 2011 and the present time. Others were oral presentations at the Metallography conferences held during that time. The focus of discussion of the failure cases in this paper is the metallurgical evaluation of failure causes. This is the approach taken in many small and industrial laboratories. A holistic approach of a failure case, which includes calculation and simulation methods such as finite element analysis, and which also implies a knowledge of the service stresses intended by design as well as the actual loading situation of the failed part, is not the aim of this contribution.