DAMAGE ANALYSIS OF A RETIRED GAS TURBINE DISC
Gas turbine discs operate mostly at high temperature gradients and are subjected to mechanical loads simultaneously.The high thermal and mechanical loads eventually could result in degradation and damages in disc material,thereby increasing the risk of disc failure.In this study,a damage analysis was performed in a retired gas turbine disc made of Inconel 718.Oxidation attack and microstructural degradation as the consequence of the high service temperature have been found to be the main damages that take place in the non-contact area of the retired disc.In the blade/disc contact area,fretting fatigue occurs,with a result that cracks initiate from the oxide/metal interface and propagate in the disc alloy parallel to the sliding direction of fretting,consequently reducing the stability and safety of the disc.Meantime,oxygen diffuses into the fretting fatigue cracks,thereby exacerbating the oxidation attack.A multi-layered scale with periodic formation of the Fe-oxide/spinel layer and the metallic layer is formed on the contact surface.In both contact and non-contact area,recrystallization and α-Cr precipitation take place in the surface layer of the disc alloy.The locations where α-Cr precipitates are commonly considered to be the natural sites for mechanical weakness.
Damage Retired gas turbine disc Inconel 718 Oxidation Fretting fatigue
Zhe Chen Johan Moverare Ru Lin Peng Sten Johansson
Division of Engineering Materials,Link(o)ping University,SE-58183 Link(o)ping,Sweden Division of Engineering Materials,Link(o)ping University,SE-58183 Link(o)ping,Sweden;Siemens Industr
国际会议
Energy Materials 2014(第一届能源材料国际会议)
西安
英文
405-410
2014-11-04（万方平台首次上网日期，不代表论文的发表时间）