| 摘要 |
993,985. Detecting flaws in surfaces. UNITED STATES STEEL CORPORATION. Feb. 8, 1963 [Feb. 23, 1962], No. 5326/63. Heading G1S. Surface defects on solid articles are detected by applying a vaporizable material to the surface of the article, the material having the characteristic of being able to penetrate into surface defects on the article, thereafter removing substantially all of the material which has not penetrated into any surface defect, maintaining the article in a condition which will allow material remaining in any defects to vapourize,and detecting vapours emitted from the material in the defects. In one embodiment, liquid trichloroethane is applied by a nozzle 20. The surface is subsequently cleared by air jet 24 and the body 11 is then heated by a coil 28 and vapour from any defects is detected by a chlorine detector 30. In an alternative embodiment for use when the body 11 is at a high temperature, a solid salt is applied to its surface, which due to the heat of the body, flows into any surface defects. The vapour escaping from the defects is detected by applying a flame to the surface. Any vapour of the salt imparts a characteristic colour to the flame and this may be detected spectroscopically. |
