Glass bead peening

The circumferential (hoop) stress in a cylinder of 1045 steel, due to water quenching followed by glass bead peening, is measured with a diffractometer (Cr Ka radiation, 211 reflection). The line shift A20 when a stiess-free specimen is rotated from = 0 to ij/ = 45° is -0.10°. Take the stress constant A", as 90 ksi/deg. The time 1 given below is the time required to accumulate 20,000 counts at each angle. 

Abrasives is a term given to various materials with different physical formats (such as aggregate, grains, shot, particles bonded with an adhesive, and so forth) that are used to wear down stufaces to desired dimensions or surface finishes or for some other purpose. They may be used in their raw state, such as with shot or glass in shot or glass-bead peening operations. Or they may be used in conjunction with adhesives and fillers to make belts, wheels, and tool surfaces. 

Example case history 1. A gas turbine s compressor rotor developed blade tensile stresses while in operation that would quickly lead to failure. The OEM specified that a glass-bead peening process needed to be conducted all over the surface of the... 

During one of the turbine s overhauls, the repair facility mistakenly only glass-bead peened one side of the compressor blades. Two engines failed during operation before the error was discovered. It was not known with which turbines the error had been made. The only way to determine this without doubt was to destructively test the compressor blades with X-ray diffraction. The entire fleet of engines that the overhaul shop had handled with that SB included had to be recalled. 

Mechanical treatment including brushing, grinding, polishing, and sandblasting and shot peening with various kinds of shot, such as metallic particles, corundum, and glass beads... 

Pickling in acid will probably be used less intensively in the coming years because of environmental problems. In many cases, optimized mechanical treatment (e.g., micropeening, an optimized form of shot peening with glass beads) will then be the substitute [2]. 

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