AXLES USING NON-DESTRUCTIVE TESTING
A company for the maintenance of railway vehicles in Slovenia carried out, in collaboration with the Institute of Metal Structures (IMK), Ljubljana, testing and relevant analyses of the state of carriage axles. In order to detect cracks at carriage axles and to evaluate the quality of axles surfaced, ultrasonic and magnetic particle testing methods were used. Ultrasonic testing with normal and angle probes was used to detect internal cracks in the carriage axles using the distance gain size (DGS) diagram and the distance amplitude correction (DAC) method for reference specimens. Additionally, the magnetic particle testing method, with an apparatus permitting the detection of transverse and longitudinal cracks, was used to search for surface cracks. The tests performed at numerous railway carriages provided results, which make it possible to predict a premature axle fracture in further service. The non-destructive testing methods used permitted the detection of the cracks present, causes for the crack initiation were established, and the risks of crack propagation were evaluated. A critical evaluation of the carriage axles in terms of crack initiation and size is given. The prediction of the remaining life of an axle with reference to the potential propagation of the existing cracks is given taking into account the load axle acting on the axle and the axle age.
Magnetic particle inspection equipment for testing railway wheelsets
As a matter of routine, railway axles which have been in service are periodically tested for possible surface-breaking cracks. One method of testing is the highly sensitive magnetic particle inspection technique which detects any fatigue cracks on the axle
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.