الفهرس 
Chapter 1 : IntroductionOnly 14 pages are availabe for public view
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Abstract
This study concerned with fabrication and checking Egyptian steel flat-bottom-hole reference blocks which are used to establish performance characteristics of ultrasonic flaw detection systems. They are also used to standardize and control the adjustment of systems for the inspection of steel products. The result of these studies could be used in the future to establish accept –reject criteria for many worked steel products.
Procedures for inspection of the material quality, fabrication of the blocks and evaluation of their physical and ultrasonic characteristics are described. Two standard steel reference sets of blocks are designed in National Institute of Standards NIS and fabricated with high precision in the metric system in Sakr Factory, Egypt.
Artificial defects of flat bottom surface are fabricated inside the blocks. The material of the blocks is the low carbon steel, which is used in Egypt in many strategy products.
These two sets are:
1-Area-Amplitude set (5 blocks) of different hole diameters (1.6, 2.0, 2.4, 2.8, 3.2 mm) and have the same metal distances above the hole (75 mm).
2-Distance-Amplitude set (12 blocks) that consists of blocks with the same hole diameter (2 mm) and different metal distances (12.5, 25, 37.5, 50, 62.5, 75, 87.5, 100, 112.5, 125, 137.5, 150 mm).
The blocks are fabricated from the same raw material of low carbon steel rod. The ultrasonic attenuation is calculated before the fabrication and it shows that, the material is homogeneous and free from any defects. The blocks are heat treated according to DIN 45120 Designation Standard and its mechanical properties are measured before and after the heat treatment. The heat treatment effect on the microstructure of the blocks material indicates that, there is no significant change in the grain size of the used steel. The ultrasonic longitudinal and shear velocities are measured in the blocks and the elastic parameters of the blocks are calculated.