Search Results

A major concern in head gasket reliability of an industrial diesel engine is flange cracking. This paper will discuss head gasket flange cracking and the head gasket joint environment as they relate to an industrial diesel engine head gasket joint. The paper will discuss metallographic and finite element analysis of head gasket field failures. The metallographic analysis will discuss the evaluation of production, assembled, laboratory tested, and field tested gaskets. The above will give head gasket designers and engine manufacturers insight into the industrial head gasket joint environment. The metallographic work will explain the method of creating micro sections as well as micro section measurements to aid in the understanding of the head gasket loading.

This paper will discuss metallurgical failure analysis of microwelded iron piston rings and aluminum pistons in internal combustion engines. “Microwelding” is defined as adherence of sporadic particles of aluminum from the piston to the bottom side of the piston ring. The paper will describe the high output water-cooled two-stroke engine accelerated test which reproduces the microwelding phenomenon in 30 minutes. SEM and EDS analyses have been used in the identification of the mechanism of this surface damage. Evidence of extreme temperatures during pre-ignition and normal operating conditions was obtained by studying hardness distributions through the piston cross section. As a potential solution, decreasing temperature through use of a thermal barrier coating was investigated. Also, test results of piston ring coatings, including molybdenum and tungsten disulfide, electroplated chromium, PVD titanium and chromium nitride, and fluoroplastic materials were compared.

This paper discusses corrosion fatigue and the corrosive environment as they relate to an industrial engine head gasket joint. The paper will identify possible corrosive elements which initiate corrosion fatigue failures. The sources of the corrosive elements will be cited with the associated concentration levels. The paper will formulate a hypothesis as to how the corrosive elements are transferred through the engine coolant system. Utilizing a Scanning Electron Microscope (SEM) and an Energy Dispersive X-ray Spectroscope (EDX), an analysis of coolant residue at the fracture will show evidence of the corrosive elements to verify the proposed hypothesis. Information from engines in the field will be compared to laboratory engine tests to show how laboratory and field results are significantly different. The main corrosive failure of the engine head gasket is flange cracking.