METHOD OF INTEGRATED CONTROL OF RAIL JOINT WELD QUALITY Russian patent published in 2019 - IPC G01N29/14 G01N29/04 

FIELD: methods and devices for metal processing.

SUBSTANCE: use: for integrated quality control of welded joint of rail joint. Summary of invention consists in the fact that conducting of continuous inspection of welded joints by ultrasonic (UTF) method and selective control of observance of preset welding mode by testing of reference natural samples for static transverse bend on press and measurements of hardness of metal in welded joints of rails, at that, in addition, continuous control is performed for presence of zones with martensite structure of metal in weld seam, acoustic emission (AE) method at stage of heat treatment of welded joints in process of air-water cooling of weld seam, simultaneously controlling temperature of weld cooling, and monitoring, by metal magnetic memory (MMM) method, welds on head and on rail foot feathers, wherein conclusion on modes of welding of rail joint, parameters of heat treatment of welded joint is made based on analysis of results obtained from all types of control, MMM is carried out to determine stress concentration zones (SCZ) in zone of thermal impact (ZTI) of weld, on its own magnetic scattering field by scanning the magnetometer sensor along the welded seam of the rail head surface and rails bottom feathers, in the SCZ, Hp is the magnetic field intensity, A/m, and the scattering magnetic field gradient Hp (dHp/dx), where x is the line of examination in the SCZ, the obtained information is stored as the initial one, then repeated diagnostics is carried out in the string in the SCZ with determination of Hp and its gradient dH/dx, when along path 50–150 mln. tons of cargo, the obtained information is stored as obtained after along path of 50–150 million tons, comparing the obtained data with the initial data obtained earlier, in case of MMM parameters growth, data are determined as maximally predisposed to destruction, identified welds are subjected to additional complex periodic inspection, in case of stable increase of MMM parameters and at detection of defect by other methods of non-destructive testing, cutting is performed.

EFFECT: technical result is possibility of detecting zones of brittle hardening structures (martensite) in welded seam of rail head.

5 cl, 8 dwg, 2 tbl