渗透探伤是利用某些渗透液体对狭窄缝隙的渗透性来检查试件和材料表面缺陷的一种无损检测方法。检测时,将渗透液涂敷于试件表面或置试件于渗透液中浸渍,由于毛细现象,渗透液被吸入缺陷内,虽经清洗仍然停留在缺陷深处。当在试件表面涂上一层极薄的吸收材料时(这种材料相当于一种显影剂),缺陷内部的残留渗透液就会被吸出,在试件表面稍稍扩展并形成与缺陷形状相 Impermeable flaw detection is a nondestructive testing method that uses the permeability of certain penetrating liquids to narrow gaps to inspect the surface defects of the test pieces and materials. During the test, the permeate is coated on the surface of the test piece or the test piece is immersed in the permeate. Due to the capillary phenomenon, the permeate is drawn into the defect and remains in the depth of the defect even after cleaning. When the specimen surface coated with a thin layer of absorbent material (this material is equivalent to a developer), the residual permeate inside the defect will be sucked out of the specimen surface slightly expanded and formed with the defect shape phase