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Wear Behavior and Phenomena
Published in Raymond G. Bayer, Mechanical Wear Fundamentals and Testing, Revised and Expanded, 2004
This distinction between initial and long-term wear behavior is significant for several reasons. One is that run-in and break-in are precursors to stable wear behavior. For the designer or engineer, this means that suitable break-in may be required to obtain the stable period of low wear rate needed for long life. If this break-in does not occur, higher wear rates and unstable behavior might persist, resulting in reduced life. It is also important in engineering because it is sometimes necessary to take into account the magnitude of the wear associated with this initial period. It is also significant in terms of its relationship to wear studies. To the investigator, this stable period provides a convenient region for wear study. It is typically the type of region
Necessity and suitability of in-line inspection for corrosion resistant alloy (CRA) clad pipelines
Published in Ships and Offshore Structures, 2023
Ahmed Reda, Mohamed A. Shahin, Ibrahim A. Sultan, Chiemela Victor Amaechi, Kristoffer K. McKee
The UT intelligent pigging used was launched at 12:40 and travelled with a relatively constant speed of 0.35 m/s. The pigging tool passed through all bends from the topside piping to the riser, including the gooseneck and expansion spools without stopping. The distance of 181 m was reached at 12:49. This distance indicates that the pigging tool passed all installations from topside to riser to gooseneck and expansion loop without any stops. The distance of 181 m was measured from the pig launcher to a position along a straight length of the pipeline on the seabed. The UT intelligent pigging tool travelled the first 181 m without any issues. At 12:48, the number of revolutions per minute (rpm) of the pump was slowed down to maintain the break tank level. The following data were valid for this stage:
Behaviors of novel manufacturing 1215MS+Bi steel in casting thermal processes
Published in Materials and Manufacturing Processes, 2023
Bin Liu, Rui-Shan Xin, Jian-Bo Xie, Jian-Xun Fu
However, when compared to these typical element-added steels mentioned above, the bismuth free-cutting steels have more advantages. (1) Bismuth is an eco-friendly element, similar to Pb in physicochemical properties, but smaller in density and macro segregation than Pb.[15–19] In 1941, Pray et al.[20] proposed to replace Pb by Bi to avoid heavy metal Pb polluting the environment and harming human health. (2) Bi has low melting point, 271.3°C, while the cutting temperature is higher than 300°C during dry cutting, so Bi film plays a good role in lubrication and melting embrittlement.[21,22] During the cutting process, a large amount of heat generated by the cutting friction makes Bi in the chip melt. The cutting tool is lubricated to avoid overheating and cutting “nodules”. The cutting energy is lower and the chip is easier to break, which improves the cutting efficiency and avoids deterioration of the surface finish of machining steel. (3) The addition of Bi in steel is only half of Pb, which can achieve the same machinability as Pb content steel.[19,23]
ATHLET Simulation of PKL I2.2 IB-LOCA Benchmark Test and Quantitative Assessment
Published in Nuclear Technology, 2022
Hong Xu, Aurelian Florin Badea, Xu Cheng
In view of the potential risks of nuclear energy, nuclear power plants (NPPs) are designed according to the principle of defense-in-depth (DID) and adopt multiple barrier protection measures.1 Regarding power plant design-basis accidents (DBAs), especially the loss-of-coolant accident (LOCA), the U.S. Nuclear Regulatory Commission (NRC) issued basic criteria for the analysis of light water reactor (LWR) accidents for the first time in the form of regulations in 1974. Based on the size of the break, LOCA can be divided into four types of scenarios: slow drain small-break loss-of-coolant accident (SB-LOCA), rapid drain SB-LOCA, intermediate-break loss-of-coolant accident (IB-LOCA), and large-break loss-of-coolant accident (LB-LOCA) (Ref. 2). IB-LOCA is defined as an accident with a rupture area between 11% and 25% of the maximum pipe cross section connected to the pressure vessel; ruptures smaller and larger than this range correspond to SB-LOCA and LB-LOCA, respectively.3