Non-riser non-chill casting method for belt pulley

Abstract

The invention relates to a non-riser non-chill casting method for a belt pulley. The method comprises the following steps: S1, designing a casting system: according to the shape of the belt pulley, drawing a red blueprint and then manufacturing the casting system according to the red blueprint; S2, casting: adding a ferrosilicon inoculation agent accounting for 0.3-0.6% of molten metal flow in weight in a casting ladle, during casting, adding a stable inoculation agent accounting for 0.4-0.7% of the molten metal flow in weight along with the molten metal flow, cooling to room temperature after completion of casting, and taking out a belt pulley blank; and S3, machining. The method provided by the invention has the advantages as follows: the fact that melted iron enters a cavity to flow turbulently to cause unnecessary artificial hole shrinkage and hole looseness is avoided through the design of a runner. The process yield and production efficiency of the product are improved; a chill production process does not exist, the defect of artificial hole shrinkage caused by misuse of improper use of the chill is avoided; different inoculation agents are added at different periods and different inoculation modes area adopted, so that the advantages of multiple inoculation agents are effectively used.

Description

technical field [0001] The invention relates to the technical field of belt pulley production, in particular to a riser-free and chill-free casting method for a belt pulley. Background technique [0002] The pulley belongs to the disc and hub parts. In 2013 alone, the output of pulleys in my country exceeded 550 million pieces. As the main supporting part of the transmission system, the development of the pulley is the top priority of this industry and the entire industrial production. In traditional pulley casting, the inrunner is only designed in a generally rectangular or cylindrical shape. This type of design not only fails to form thermal pressure and temperature gradients, but also tends to cause faster heat dissipation in the inrunner and earlier solidification of the molten iron , thus blocking the subsequent flow and replenishment of molten iron. At the same time, the gating system with a riser is used in the traditional pulley gating system design. Generally, the...

AI Technical Summary

Problems solved by technology

This type of design scheme not only increases the amount of molten iron, cumbersome subsequent processing operations, and increases production costs; it is also easy to introduce external impurities and gases from the riser, forming inclusions and pore defects inside the casting, seriously affecting the internal quality of the casting and process yield

[0003] Cold iron is also an inevitable choice in the traditional pulley casting process design, but the cold iron is processed from low-carbon steel or wire rods coated with tinned or anti-adhesive film slurry. The material itself has limited the use of the cold iron and cannot be used multiple times. and high efficiency, which obviously cannot meet the current high-efficiency production mode

In addition, the use of cold iron requires the accumulation of experience of the workers and masters. If it is not used properly, it will not only fail to refine the primary crystallization and eliminate shrinkage cavities, but also cause temperature gradient chaos, solidification sequence disorder, and cause more internal defects.

At the same time, the complex manual operation of cold iron reduces production efficiency and increases production costs, which is not conducive to the improvement of economic benefits

[0004] The traditional inoculation of belt pulley is based on low carbon equivalent and the premise of ensuring that the original molten iron has sufficient supercooling degree, so the following problems will inevitably occur: 1. The fluidity of molten iron is poor, and castings are prone to cold laps, pores, slag inclusions, etc. , high scrap rate

2. The large shrinkage makes the casting easy to form shrinkage cavity, shrinkage porosity, crack, deformation, etc., and the scrap rate is high

3. The inoculation decline is fast, the supercooling tendency is large, and the section sensitivity is high, which will not only produce white spots in the thin-walled parts of the castings, which will bring difficulties to the cutting process, but also reduce the strength of the thick-walled parts of the castings, making it difficult to meet the requirements of mechanical properties. Require