تخمين عمر باقيمانده خزشي پره هاي توربين گازي ساخته شده از سوپرآلياژ پايه نيكل IN 792

Remaining Creep Life Assessment of Gas Turbine Blade Made of IN 792 Nickel-Base Superalloy

در اين مطالعه، عمر باقيمانده پره ي توربين ساخته شده از IN 792 كه به مدت 80000 ساعت در دماي 1000 درجه سانتيگراد كاركرده است، با استفاده از بررسي هاي ريزساختاري، تحليل هاي نرم افزاري و آزمون هاي مكانيكي بررسي گرديد. در اثر كاركرد در دماي بالا، تحت تنش ثابت و زمان طولاني فازهاي مخرب در ريزساختار پره توربين تشكيل شده و مورفولوژي فاز رسوبي گاما پرايم از حالت ايده ال خود انحراف پيدا كرده است و استحكام تنش-گسيختگي پره نسبت به آلياژ كارنكرده، افت نشان مي دهد. كه نتيجه آن اين است كه عمر كاري به پايان رسيده است

During the operation, the turbine blades of hot gas path suffer service induced degradation due to different causes such as creep, fatigue, oxidation, corrosion and etc. The present study was carried out the effect of long-term service at the high temperature exposure to remaining life assessment gas turbine blade made of Inconel 792 nickel base superalloy. That is investigated by studying on microstructure by optical and scanning electron microscopy, mechanical properties such as high temperature tensile and stress-rupture test and stress analyses of turbine blade. The result has been shown the gamma prime rafting and TCP phase formation has occurred at the microstructure. Because of long-term service at high temperature, stress- rupture properties of blade reduced and 20% lower than new IN 792 alloys. The stress analyses with ANSYS software and creep life assessment results by use Larson-miller parameter, the safety factor of blade lower than 1 and life time of turbine blade is finished.