New developments in nondestructive quality control at state bearing factory No. 4

Abstract

Reliability and endurance of roller bearings are mainly governed by the quality of materials used in their manufacture, heat treatment, and condition of the working surfaces. The stringent requirements set out for the efficiency of roller bearings and their assemblies give rise to the need for using methods of nondestructive quality control (NQC). Nondestructive control at State Bearing Factory No. 4 (GPZ4) is used extensively in different stages of production, starting with quality control for the metal and ending with quality control for the manufactured part. The main areas for use of NQC are revealing metallurgical and technological defects in the form of cracks in the original metal, blanks, and manufactured articles, monitoring of heattreatment quality and grade of material for blanks and articles, monitoring of the working surface of manufactured articles for the presence of defects associated with local structural inhomogeneity (e.g., grinding burns). Extensive use is made of magnetic powder, magnetic-luminescence, and luminescence defectoscopy, different electromagnetic monitoring methods and also ultrasonic monitoring. In the last 10 years the main development in this factory has been the use of an electrical induction method for nondestructive testing (the eddy-current method) providing high measurement accuracy with high productivity as a result of automation of the monitoring operations.