Part of #Material , Structure and Hardness testing of Cast-iron safety parts by using NDT methods# :
Publishing year : 2008
Conference : Second International Conference on Technical Inspection and Non-destructive Test
Number of pages : 17
Abstract: In the past, the manufacturers of safety cast -iron parts were only executing a random check to control their production line as relatively high rate of defective parts were acceptable. Nowadays, due to the market demand, because of the production of high speed vehicles, they continue to reduce the weight of parts and consequently, using a lower safety design factor, and finally due to high competition in the word market, very high quality components are only required and very low rates Defective parts even lower than the range of PPM is acceptable. Therefore, the random check is no more adequate at all, and 100% of the products should be tested. In testing safety parts, 2 categories of test must be executed: 1-Flaw detection to find defects like: porosity, shrikage. cracks and inclusions .2- Checking material mix, structure, heat treating process, microscopic texture, graphite type and properties like tensile strength, hardness and case depth. In this study, we concentrate on the second category of tests. All of these tests can be done only by fast, reliable and re-producible NDT methods. Different NDT methods, such as Eddy Current Testing (ET), Ultrasonic Testing (UT), Resonance Testing , Vibration analysis (VA) or Thermograhy are used for 100% testing of such parts. In this paper, more common methods i. EESTI ET UT nd their capabilities as well as applications are described. A practical test for the production line of Pride passenger cars to check the nodularity and hardness of 3 types of cast iron to safety by both methods have been reported By comparing the results of both methods on the same parts, the conclusion and comments to select the proper test method has been presented.