Engineering Design and Testing Corporation

Cayce, United States

Engineering Design and Testing Corporation

Cayce, United States
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Jur T.A.,Engineering Design and Testing Corporation | Harris R.D.,Engineering Design and Testing Corporation
Journal of Failure Analysis and Prevention | Year: 2014

A paper manufacturing machine experienced an in-service fracture of one of the machine's felt guide rolls. An engineering analysis of the fractured roll was conducted to determine the cause. Consideration was given to resonant vibration of the roll with respect to operation of the machine at or near the natural frequency of the roll. However, analysis demonstrated that vibration was not an issue. Rather, the roll fracture was attributed to a high cycle fatigue fracture mechanism associated with a plug weld at a threaded fastener used to attach a large balance weight to the inside of the roll. The balance weight was, in turn, installed to compensate for variation in the wall thickness of a pipe product used to make the roll. The cause of the roll fracture was defective manufacture. © ASM International 2014.


Jur T.A.,Engineering Design and Testing Corporation
Journal of Failure Analysis and Prevention | Year: 2013

The analysis concerns back-to-back losses of a spincaster used in the manufacture of rolls for rolling mills. Both losses involved the fatigue fractures of parts used to secure the mold for the roll being cast in position while spinning. The fractures are analyzed as to cause so as to avoid yet another occurrence. Further, since the loss incidents were accompanied by loud noises and by molten metal flying about, interpretation of the fracture also involved dispelling the notion that there was an "explosion." © 2012 ASM International.


Stewart G.,Engineering Design and Testing Corporation | Harris R.,Engineering Design and Testing Corporation
Materials Science and Technology Conference and Exhibition 2010, MS and T'10 | Year: 2010

Determining the scope of damages and repairs or replacements required after a commercial or industrial fire is the first step in restoration of the property. Knowledge of the properties of various engineering materials is an essential tool of the engineer conducting a scope of damage evaluation. Field observations combined with knowledge of material properties and the behavior of those materials with exposure to various temperatures allows the investigating engineer to determine the local temperature exposure experienced by different structures and equipment items. Armed with this knowledge of the local temperatures, knowledge of the properties of the materials of construction allows an immediate assessment of the likelihood of damages to specific components, even those not immediately accessible, without detailed disassembly and examination. This allows rapid segregation of items that are likely repairable from those that are probably not, leaving only any items still in question for detailed disassembly and examination. Copyright © 2010 MS&T'10®.


Jur T.,Engineering Design and Testing Corporation | Windham R.,Engineering Design and Testing Corporation
Materials Science and Technology Conference and Exhibition 2010, MS and T'10 | Year: 2010

Following a hurricane at a seaport, four cranes were found in a mass of deformed steel at the end of the dock. The cranes had all been tied down prior to the storm. Assuming effective tie down procedures and that there was no pre-storm loss of integrity, the cranes should have stayed in place. It so happened that the cranes belonged to two different shipping companies. The extent of the loss made it important to identify which of the cranes broke loose first, thereby allowing assignment of responsibility for the damage. By a careful study of the damaged condition of the cranes, a reconstruction confirmed assignment of responsibility. Copyright © 2010 MS&T'10®.


Traubert T.D.,Engineering Design and Testing Corporation | Jur T.A.,Engineering Design and Testing Corporation
Journal of Failure Analysis and Prevention | Year: 2010

Aluminum alloy pistons, one each from two of the same model internal combustion engines, experienced fracture. The alloy would have been heat treated-solution treated and aged-to obtain an intended as-manufactured hardness. Hardness tests suggested that both pistons had been subjected to elevated temperature and, hence, were overaged. To prove the point, material from an undamaged piston was purposely overaged. The overaged hardness was consistent with the hardness of the materials from the fractured pistons. Fragments from a damaged piston were then solution treated and optimum aged, the result being restoration of material hardness. The heat-treatment experiments determined that the reduced hardness of the fractured pistons was incident related and not manufacturing related. Physical evidence also indicated that the pistons had seized in the engines. The result was fracture of the pistons because of overaging by heating when the pistons seized. The result of the heating was to reduce the hardness and strength of the piston material. © 2009 ASM International.


Traubert T.D.,Engineering Design and Testing Corporation | Jur T.A.,Engineering Design and Testing Corporation
Journal of Failure Analysis and Prevention | Year: 2012

A pintle chain composed of a cast 310 stainless steel material experienced embrittlement, deformation, and multiple fractures after operating six months inside a furnace. The design is such that the chain travels the length of the furnace, experiencing temperatures cycling between ambient and 1,700 F in an oxidizing atmosphere. Pins comprising the individual chain links had experienced deformation, and in some cases, had also fractured in a brittle manner. The links comprising the chain had also experienced numerous fractures in a brittle manner. An analysis of the loads experienced by the pins and links determined that both the short-term yield strength and the long-term creep strength of the pins had been exceeded at the normal operating temperature of the furnace. Furthermore, metallurgical analysis of the pins and links determined that carburization had taken place, embrittling the pins and links. A change to the original design of the furnace had resulted in the unintended presence of the carburizing atmosphere inside the furnace during the first 6 months of operation. The carburizing atmosphere was alleviated by returning to the original furnace design. Upgrading the alloy selection for the chain provided further resistance to service-related embrittlement, increased ductility when cycling to ambient temperature, and increased high temperature strength. Increasing the size of the links and pins was recommended (an upgrade to a higher chain load rating), but was not practical, given the dimensional constraints of running the chain in the furnace. © ASM International 2012.


Traubert T.D.,Engineering Design and Testing Corporation | Jur T.A.,Engineering Design and Testing Corporation
Journal of Failure Analysis and Prevention | Year: 2012

A spiral heat exchanger (SHE) constructed of Grade 316L stainless steel developed a leak after 8 years of service as a condenser on a distillation tower. Examination of the SHE identified the leak as being located on the cooling water side in the heat affected zone (HAZ) of a weld joining two plates. Cooling water deposits were observed in a V-shaped corner formed by the weld. A metallurgical examination identified the presence of transgranular cracks at the HAZ on the cooling water side. Analysis of the cooling water revealed the presence of chlorides. Based on the metallurgical analysis and the presence of chlorides, it was determined that the cracks and resulting leak were the result of chloride stress corrosion cracking. © ASM International 2012.


Rose A.M.,Engineering Design and Testing Corporation
Journal of Failure Analysis and Prevention | Year: 2010

From drying your hair in the morning to using your computer at work to watching a DVD on your big screen TV at night, transformers are involved in the many things we do every day. As the name implies, transformers transform electricity from one voltage to another. In the early days of electricity, it was costly to move electricity from Point A to Point B. As a result, people who wanted electricity had to live very close to a power plant. At the 1893 World's Fair, George Westinghouse and Nikola Tesla introduced alternating current, or AC power, to the world. Up until this time, Thomas Edison's direct current, or DC power, was the only form of electricity in the United States. Among the many positive attributes of AC power, engineers discovered that if the power could be converted (or transformed) to use higher voltage and lower current, then it would be cost-effective to transport the electricity over longer distances from a power plant to a home or business. This discovery and the invention of the transformer led to the power distribution system as we know it today. Transformers are the backbone of our electrical transmission and distribution system. Of these, high- and medium-voltage transformers are the most complex and the most expensive pieces of equipment in this system. Consequently, it is important that transformers be properly constructed and maintained to ensure a long service life. © 2010 ASM International.

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