Installation for automatic ultrasonic examination of mill rollers


Installation for automatic ultrasonic examination of mill rollers

The installation is intended for the automatic ultrasonic examination of the metal of drums from Ø1200 to 1600 mm and from 1000 to 4000 mm long, and conical necks of forged mill support rollers manufactured as per OST 24.013.04-90E from 60HN and 75HMF, 90HF steel, in order to detect and measure defects according to the requirements of OST 24.023.22-81.

Structure of the installation

An installation for automatic ultrasonic examination includes the following main units and systems:

  • acoustic unit with ultrasonic converters;
  • scanning mechanism, consisting of rotary table, gear box for raising/lowering the acoustic unit bracket, and cleaning brush for cleaning roller surfaces;
  • “SCANNER” 8-channel automatic ultrasonic gaging installation;
  • computer-based data processing, display and archiving system;
  • acoustic unit coordinate tracking system, including:
    • roller swivel angle transducer;
    • longitudinal coordinate counter;
  • reference point recognition transducer;
  • contact fluid feed system;
  • auxiliaries.

urally the installation is designed as a dust- and moisture-proof instrument rack mounted on a free area (platform) of a grinding lathe frame, with a removable scanning mechanism mounted in a tool holder, and an acoustic unit. The installation uses the echo method of ultrasonic examination in the 1.25–2.5 MHz frequency band. In terms of resistance to adverse environmental conditions (climatic factors, dust, moisture) the installation is compliant with 4.1. as per GOST 23049-84. For protection against dust and moisture penetration inside the electronic device, the installation complies with group IP54.

Capabilities of the installation

The automatic ultrasonic examination installation provides automatic testing of drums and necks of support rollers made of 60HN, 75HMF and 90HF steel of the following dimensions:

  • drum diameter: 1200–1600 mm;
  • drum length: 1000–4000 mm;
  • number of channels: 8;
  • configurations for scanning of roller drum and neck, and type of piezoelectric converter:
  • upright piezoelectric converter to scan the entire thickness of the drum and neck;
  • oblique piezoelectric converter with a 40° introduction angle in centerline plane and minimum scanning depth to the roller centerline;
  • oblique piezoelectric converter with a 50°(55°) introduction in centerline plane and scanning depth to the roller centerline;
  • oblique piezoelectric converter with a 60° introduction in centerline plane and minimum scanning depth to 0.2 of the roller drum thickness;
  • oblique piezoelectric converter with a 70°(65°) introduction in centerline plane and minimum scanning depth to 0.2 of the roller drum thickness;
  • surface waves in centerline and radial planes of the roller for surface defect detection;
  • head waves in centerline plane for detection of subsurface transverse defects;
  • for examination of rollers with deposited metal there is the possibility of replacing one of the piezoelectric converters by a separated-combined piezoelectric converter for detecting incomplete fusion between base metal and deposited metal;
  • scanning range (longitudinal waves): 0–2400 mm;
  • linear scanning speed: 100–300 mm/sec;
  • registration increment:
    • path along generator: 5 mm;
    • roller swivel angle: 1 °;
    • defect coordinate determination error (without account of quasi-distortion of directional diagram): not more than 1%;
    • operating mode setting time: not more than 1 minute;
    • data presentation: digital and graphical forms;
    • data archiving in computer;
  • Dimensions of the installation:
    • flaw detector: 620 x 210 x 230 mm;
    • scanning mechanism with acoustic unit: 400 x 1400 x 300 mm;
  • Power supply: AC 220 V±22%.