Test And Research On Wear Resistance Material For High Speed Railway Freight Car Bogie

CNR Qiqihar Railway Rolling Stock (Group) Co.,Ltd. (QRRS) developed a new type of swing Motion (SM) bogie with maximum running speed of 160 km/h to meet the needs of freight wagons running at higher speed. SM bogie is improved on the basis of original three-piece (bolster and side frames) bogie, through add of a spring plank (lateral connecting girder) between the two side frames, laying of the bolster and spring sets on the spring plank and connection of bottom of spring plank with rocker seats. Although SM bogie looks like three-piece steel casting bogie in the structure, all components are re-designed entirely. The service conditions of two wear fits, rocker seat to base portion and plate member to adapter, are very strict. The two wear fits meet strength requirements and prevent themselves from deterioration due to excess wear and contact fatigue. Five types of metallic materials are selected for the project. The different heat-treatment processes are contrastively tested and studied. Selected materials and heat-treatment processes are as following: grade B casting steel (normalization, normalization + surface quenching), grade C casting steel (normalization, normalization + surface quenching), grade E casting steel (quenching and tempering, quenching and tempering + surface quenching), 45# casting steel (normalization, quenching and tempering) and spherical cast iron (Bainite quenching: soft, semi-harden and harden). Rolling contact fatigue test and wear test are mainly carried out besides the conventional mechanical performance tests for materials above. The test indicates that contact fatigue life and wear resistance of surface quenched casting steels and Bainite quenched spherical cast iron are increased largely. These two wear fits are better produced by surface quenched grade C casting steel in normalization condition or surface quenched grade E casting steel in quenching and tempering condition and Bainite quenched spherical cast iron . Grade C casting steel is used for adapter, grade E casting steel for rocker seat and spherical cast iron (by 880 ~900℃heating and 300 ~ 340℃Bainite quenching) for plate member and base portion. The conventional mechanical properties of three types of materials above can meet the requirements of design .