However they are all functions of temperature, and with the extremely high temperature range experienced in internal combustion engines one can obtain significant errors. Correlations between fatigue performance and microstructure were made and discussed, with the results examined in light of current and proposed models for predicting fatigue performance based on computational methods, to see if any suitable models exist that might be used to assist in designing with these cast alloys.ДЄrchive/lib.dr./etd/14805/Eisenmann_iastate_0097E_15307. We recall from the previous section that the nominal specific heat capacity values used for air at 300K are C v 0.717 kJ/kg.K, and k 1.4. Follow on work involved high temperature fatigue testing of these two materials in order to better determine if the newer alloy, HSM is a better choice for exhaust manifolds. The initial examinations concluded that both cast irons performed fairly similarly, although the microstructure of the HSM samples did show slightly better resistance to high temperature as compared to that of the 50HS. Initial results obtained include microstructure examination after being exposed to high temperatures, grain size, nodule size, and hardness measurements. Course Overview and Classification of Internal Combustion Engines - Part 02.

Of particular concern for the high Si+C cast irons (and Mo in the case of the HSM cast iron) are subsurface microstructural changes that result due to heat treatment including (1) decarburization, (2) ferrite formation, (3) graphitization, (4) internal oxidation of the Si, (5) high temperature fatigue resistance, and (6) creep potential. Course Overview and Classification of Internal Combustion Engines - Part 01. For this study two different types of cast iron, 50HS and HSM will be examined. This thesis seeks to answer the question: вЂњCan observed microstructural changes and measured high temperature fatigue life in cast iron alloys be used to develop a predictive model for fatigue life?вЂќ the importance of this question lies in the fact that there is little data for the behavior of cast iron alloys at high temperature. Over time cast iron is susceptible to microstructural changes, corrosion, and oxidation which can result in failure due to fatigue. Cast iron has been used for manifolds for many years by auto manufacturers due to a combination of suitable mechanical properties, low cost, and ease of casting.

In the design of exhaust manifolds for internal combustion engines the materials used must exhibit resistance to corrosion at high temperatures while maintaining a stable microstructure.

Internal combustion 4 cast