The Study On Quantitative Phase Analysis Method And Application Of GH169 Alloy

The development of high temperature alloys started at 1930s, it resulted from the need of more heat-resistant materials in the supercharger of turbine in the engines airplanes, and the incessant development of aviation technology also accelerated it.There are many kinds of high temperature alloys, two kinds of series are basically used, nickel-based and iron-based high temperature alloys. GH169 (Inconel718) alloy is one kind of nickel-based high temperature alloy with ageing treatment rigidification. The ageing treatment intensification is mainly throughγ″phase of metal compound with the other effect of mensurableγ′phase. The remarkable trait of this kind of materials is that it contains much more quantities of Nb element. The component of materials changes with the claims of use of different parts, it is manifested in controlling the content of depositional intensified Nb element, microelements and gas.On the basis of the electrochemistry analysis of GH169 super-alloy and its precipitates, a respective extraction technique of (γ″+γ′),δand NbC phases was employed, and their quantitative analysis was successfully fulfilled. The quantitative phase analysis results are in good agreement with those obtained through the X-ray diffraction (XRD) quantitative phase analysis method previously proposed. According to the distribution relationship of alloy elements inγ″toγ′phase, the ratio of weight fraction ofγ″toγ′phase is calculated and is believed to be a constant equal to 3. This result is adopted for the correction of the XRD quantitative phase analysis method. Influences of cold rolling on the ageing behavior of GH169 were studied using the corrected XRD quantitative phase analysis method. The result shows that cold rolling has little effects on the morphology ofγ″andδphases, but accelerates its precipitation markedly. Moreδphase and lessγ″phase can be detected for the double rolling process related to the one rolling process. The direct ageing (DA) processes has little effect on the content ofγ″,γ′andδphase, and the corresponding microstructure is characterized as fine grain and high-density dislocation.GH169 is studied as one kind of commonly used objects, and the result is hoped to guide the thermal technics of these alloys and other high temperature alloys.