前言我厂应用的3～7毫米之薄鋼板在原材料檢查中发現其內存在有夹杂层。由于原材料檢查为破坏性檢查,为了进一步保証产品质量,我們有必要寻找无損檢查的方法。从五月下旬开始,我們对7毫米厚的鋼板进行了試驗,取得了一些效果。在超声波領域中,我們采用的方法有:双斜探头法、单斜探头法、钢板多次反射法、液层增厚法及双聚焦探头法。除此而外,我們对电位差 Preface Our factory application of 3 to 7 mm thin steel plate found in the raw material inspection there are mixed layers. Due to the destructive inspection of raw materials, in order to further ensure product quality, we need to find non-destructive inspection methods. From late May, we tested the 7mm thick steel plate and achieved some results. In the field of ultrasound, we use the method: double-angle probe method, single-angle probe method, multiple reflection plate method, the liquid layer thickening method and the dual-focus probe method. In addition, we are on the potential difference