公开(公告)号：US4818935A

公开(公告)日：1989-04-04

申请号：US26793

申请日：1987-02-05

申请人： Michiaki Takahashi ,  Mitsuo Yoshida ,  Kazuyoshi Miyazawa ,  Sigeyuki Nitta ,  Junichi Fujisawa ,  Nobuji Obara ,  Shoji Hayashibe ,  Yoshikazu Sawada

发明人： Michiaki Takahashi ,  Mitsuo Yoshida ,  Kazuyoshi Miyazawa ,  Sigeyuki Nitta ,  Junichi Fujisawa ,  Nobuji Obara ,  Shoji Hayashibe ,  Yoshikazu Sawada

IPC分类号： G01N27/83 ,  G01N27/90 ,  G01R33/12

CPC分类号： G01N27/9013

摘要： Method and apparatus for non-destructive inspection of flaws in metal materials include exciting coils centered on a longitudinal axis of a cylindrical or columnar metallic material to be examined being arranged to surround the examinee material. A multiphase alternating current of such a relatively low frequency as to cause the exciting coils to generate a rotating magnetic field which rotates about the longitudinal axis of the examinee material is superimposed with a high frequency alternating current having an inspection frequency selected on the basis of the necessary sensitivity for detection of surface flaws of the examinee material. The composite multiphase current is applied to the exciting coils so that an electromagnetic effect induced in the surface of the examinee material by the high frequency alternating current is rotated for shifting circumferentially about the examinee material along with the rotating magnetic field. A detecting element group disposed in the proximity of the surface of the examined material detects the changing of the electromagnetic effect, dependent on the presence or absence of a surface flaw of the examinee material.

摘要翻译： PCT No.PCT / JP86 / 00340 Sec。 371日期1987年2月5日 102（e）日期1987年2月5日PCT提交1986年7月2日PCT公布。 公开号WO87 / 00287 1987年1月15日的日期。用于金属材料中的缺陷的非破坏性检查的方法和装置包括以被检查的圆柱形或柱状金属材料的纵向轴线为中心的励磁线圈，被布置成围绕受检材料。 这种相对低频率的多相交流电流使得激励线圈产生围绕受检材料的纵向轴线旋转的旋转磁场，其叠加有具有基于所述受检材料的纵向轴线选择的检查频率的高频交流电 检测被检物质表面缺陷的必要灵敏度。 将复合多相电流施加到励磁线圈，使得通过高频交流电流在受检材料的表面中感应的电磁效应被旋转，以便随着旋转磁场围绕受检材料周向移动。 设置在被检查材料的表面附近的检测元件组根据受检材料的表面缺陷的存在或不存在来检测电磁效应的变化。