Many parts of construction machinery such as bulldozers and excavators are cast steel castings, which often have shrinkage defects. Light shrinkage and porosity will increase the cost of repair and inspection, and heavy shrinkage and porosity defects will lead to the scrapping of steel castings.
Combined with the actual production process of casting enterprises, the research on eliminating shrinkage cavity and porosity defects of steel castings has important guiding significance and practical value for improving the process design level of enterprises, improving the quality of steel castings and reducing costs.
Based on the analysis of the shortcomings of traditional process design based on experience and process manual, a more perfect and reasonable casting process design method and production process control measures are provided to avoid the occurrence of shrinkage cavity and porosity defects. The main research results are summarized as follows:
(1) Taking a bracket steel casting as an example, the traditional steel casting process design is carried out based on the theories of filling capacity of liquid metal, solidification mode of casting and shrinkage of casting.
(2) During the trial production of steel castings, shrinkage defects appear. Through the anatomy and analysis of the defects, the shortcomings of the traditional process design method of steel castings are inferred, and the improvement measures are put forward, and then verified by production and application. According to the successful experience of trial production, the improved Wang Yi design method of steel castings is summarized.
(3) The correctness and effectiveness of the improved process design method for steel castings are verified by listing three examples of defect improvement of steel castings.
(4) The measures to prevent shrinkage cavity and porosity in production process control are analyzed.
(5) The methods of eliminating shrinkage cavity and porosity defects of steel castings are summarized.