Casting method for Ni-B-Si alloy surface modified composite valve body

Abstract

The invention discloses a casting method for a Ni-B-Si alloy surface modified composite valve body. The casting method comprises the following steps: (1) preparing a pouring solution which comprises the following chemical components in percentage by weight: 0.22-0.26% of C, 0.25-0.45% of Si, 0.60-0.80% of Mn, 0.03-0.05% of Y, 0.05-0.10% of Pr, 0.10-0.15% of La, 0.15-0.25% of Cu, no more than 0.03% of P, no more than 0.02% of S and the balance of Fe; (2) preparing casting-infiltration coating; (3) pouring the valve body; and (4) performing heat treatment and finishing. A uniform and stable casting-filtration composite layer is formed on the surface of the valve body obtained through the casting method, and the valve body has the advantages of being high in anti-impact toughness, excellent in corrosion-resistant and high-temperature-resistant performance, high in finished product ratio, stable in quality, high in appearance quality and usability, and long in service life.

Description

technical field [0001] The invention relates to the technical field of valve casting, in particular to a casting method for a nickel-boron-silicon alloy surface-modified composite valve body. Background technique [0002] Valves are important components for the conveying and control of flowing materials. In use, in addition to meeting the requirements of technical indicators such as temperature and pressure, they must also meet the different needs of materials with different properties, such as corrosion, wear, adhesion, etc. At the same time, the sealing performance and service life of the valve are also very important technical indicators. [0003] The casting infiltration method is to make alloy powder and other raw materials into paint and brush it on the surface of the mold. When pouring, the matrix metal liquid penetrates into the capillary pores of the paint, and the alloy powder is melted and melted by the heat of the metal liquid, and is fused with the base metal. ...

AI Technical Summary

Problems solved by technology

However, due to the problems of pores, slag inclusions and uneven thickness of the surface composite layer, the casting infiltration technology is prone to problems, which will lead to casting defects when it is actually applied to the production of valve bodies, which will affect the appearance quality and service life of the valve body.

The literature "Research on Improving the Wear Resistance of Cast Steel Valves by Casting Infiltration" uses the casting infiltration process to make valves with good erosion resistance, which improves the service life of the valves, but it also points out that the problem of poor quality stability of the infiltration layer is still exists, needs to be further improved