Inspection and test are important means to ensure the quality of steel castings and the process quality of steel castings. In the production process of coupler, in addition to the inspection of raw materials, the real-time monitoring of various process parameters of medium sand in sand treatment system, and the inspection of chemical composition, mechanical properties, metallographic structure, inclusion morphology and hardness of steel castings, the physical quality and state of steel castings need to be inspected and evaluated in all links of steel castings circulation. Before the steel castings are painted with oil, special inspectors shall inspect the finished products of the hook body and hook tongue (including surface quality, flaw detection and sample inspection), and the small parts of the outer hook (hook tongue pin, lower lock pin rotating shaft, etc.) shall be used after passing the incoming inspection.
After the steel castings of the coupler are assembled, special inspectors shall inspect the assembly clearance, three state action and anti jumping performance of each part. Meanwhile, during the trial production of coupler steel castings, relevant material tests and type tests were carried out as required, such as dynamic tear, end hardenability and ton pull test.
In conclusion, the quality inspection items of coupler steel castings mainly include: physical and chemical properties, compactness of specified section, surface quality and appearance size, hardness, FeO content of slag sample in reduction period, dynamic tear, hardenability, static load tension, etc.