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Abstract: This paper focuses on the locations, causes, and improvement measures of cracks that are prone to occur in the pump body of multi-stage pumps during sand casting. Starting from the structure of the multi-stage pump body and combining with the key processes of sand casting, a systematic analysis is conducted. The study indicates that the flange connection area of the multi-stage pump body, the root of the blades, and the areas with sudden changes in wall thickness are the high-risk points for cracks. The main reasons are structural stress concentration, improper casting process control, and the characteristics of stainless steel material. The main text deeply explores the influence mechanism of each process on casting defects (such as cracks), and proposes targeted optimization solutions, including improving the structural design, enhancing the strength of the sand mold, and controlling the pouring parameters. The full text emphasizes reducing the occurrence rate of cracks in the casting pump body through refined operation management and improving the reliability and production efficiency of the stainless steel multi-stage pump body.

Recently, Dalian Jiachuang Metal Manufacturing Co., Ltd. (hereinafter referred to as "Jiachuang Metal") has achieved a major technological breakthrough in the field of sand casting. Its independently developed patent technology has successfully solved the manufacturing challenges of OH pump steel casting impellers. According to third-party testing, the comprehensive qualification rate of impellers has increased from the industry average of 85% to 99%, and the production cycle has been shortened by 40%. This achievement not only fills the technical gap in high-end pump castings in Northeast China but also marks the innovative strength of local small and medium-sized enterprises in industrial upgrading.

On October 26th, the 17th Asian Foundry Conference and the 2025 China Foundry Week, themed "Green Foundry, Innovative Asia," opened at the Xi'an International Convention and Exhibition Center. On the first day of the conference, six technical forums were launched, the international foundry exhibition gained increasing popularity, and the atmosphere for professional exchange and business negotiations became increasingly vibrant.

As a core flow component in fluid machinery, guide vanes are extensively used in critical equipment such as water turbines, pumps, and compressors. Their performance directly impacts the efficiency, stability, and service life of the entire system. These components must withstand complex hydrodynamic loads, material corrosion, and temperature fluctuations, requiring stringent specifications for material properties, structural precision, and surface quality. Casting serves as the primary manufacturing method for guide vanes, involving multiple critical processes including material selection, mold design, melting and casting, heat treatment, and quality inspection. The quality of the casting process directly determines the final product's performance. This article will delve into the technical aspects, process optimization, and quality control of cast guide vanes.

Abstract: This paper systematically analyzes the causes, common processes and locations of sand hole defects in the sand casting process of BB3 type multistage pump bodies in cast steel parts, and proposes targeted solutions. Through literature review and case analysis, it was found that the defects of sand holes mainly result from insufficient strength of the molding sand, design flaws of the gating system and improper operation, and are prone to occur in the molding, core setting, closing and pouring processes. The specific locations include gates, risers, thick parts of castings and inner cavities. By optimizing the proportion of molding sand, improving the design of the gating system and strengthening process control, the occurrence rate of sand holes can be effectively reduced and the quality of castings can be improved.

Recently, Dalian Jiachuang Metal Manufacturing Co., Ltd. (hereinafter "Jiachuang Metal") has made a critical breakthrough in sand casting of steel casting impellers—the core of OH pumps—via independently developed patents.

In sand casting, shrinkage cavities and shrinkage porosity are the most common internal defects in castings. Shrinkage cavities typically manifest as irregular large cavities in thick areas or heat center zones of the casting, characterized by rough walls and dendritic crystals. Shrinkage porosity appears as fine dispersed pore clusters, predominantly occurring along casting axes or at thickness junctions. These defects severely compromise mechanical properties and airtightness, potentially leading to cracks and premature failure. As core processes in the casting workflow, mold design and core-making operations play a decisive role in preventing shrinkage porosity and cavities. This article systematically outlines effective measures to reduce their occurrence rates by focusing on critical aspects of mold-making procedures.

Castings, as an important component of modern manufacturing, are widely used in multiple fields such as automobiles, aerospace, construction, and machinery. It is not merely a process of transforming metals or other materials into specific shapes, but also a complex technology that integrates art and science. This article will delve deeply into the definition, process flow, application fields and future development trends of castings.

According to customs data, from January to October 2024, the total import and export volume of 20 HS codes of castings in my country was 5.172 million tons, a year-on-year increase of 12.31%, and the total import and export value was 157.5 trillion, a year-on-year increase of 6.92%; among them, exports accounted for the main part, with an export volume of 5.066 million tons, a year-on-year increase of 12.39%, and a total export value of US$14.19 billion, a year-on-year increase of 5.78%; the import volume was 106,000 tons, a year-on-year increase of 8.72%, and the total import value was US$1.56 billion, a year-on-year increase of 18.62%.