How to repair Casting impregnation

1. How to repair Casting impregnation The defects in the pressure-bearing stainless steel castings (porosity, pinholes, shrinkage and shrinkage, etc.) seriously affect the compactness of the castings, so that the castings are scrapped and the economic losses are huge. The impregnation of castings is the easiest and effective way to solve the leakage repair method. Infiltration is putting the glue-like infiltration into the pores of the casting, and then solidifying the infiltrant into the inner casting wall as a whole, which repairs the leakage. 1. Infiltrant 1) Inorganic infiltrant mainly composed of sulphates, aluminates, chlorides, silicates and molten low melting point metal. Currently the most widely used infiltrant is modified silicate impregnant. It is non-toxic, non-polluting the environment, easy to store, enduring acid &alkali, high temperature, good interstitial ability, solidified in room temperature, easy to wash with water ,wide source of raw materials, easy manufacture, low prices and so on. 2) Organic infiltrant is composed of synthetic oil and epoxy resin, phenolic resin, alkyd resin, polyester, anaerobic and other synthetic resin infiltrants. Ordinary synthetic resin infiltrant has a good sealing effect, which can fill a small pore (minimum pore size 0.2ram), corrosion resistance,

2. high temperature (2000c) endurance, and so on. But it has pollution of the environment, needs heat curing and other shortcomings and now it is uncommonly use. Anaerobic resin infiltrant has good curing performance, small surface tension, less than 20mPa • s of viscosity , high penetration efficiency, solvent-free, no expanding and shrinking when curing, infiltration processing 0.5mm below of pores , insulation and fluorine resistance. But the price is high, the commonly used anaerobic resin infiltrants are AIs ~ 10A , AIS a 10B , AIS ~ 10zY-sI .The first is used for cast iron and cast aluminum pieces; the second is used for copper castings; the third is mainly used for microporous local infiltration treatment of steel , Iron, copper, aluminum castings. 2. The infiltration process 1) Local infiltration: It includes brushing method, injection method, infiltration method and vacuum decompression local infiltration and other methods and is applicable to small batch production with simple equipment, construction convenience, low cost. Therefore, the mostly used is anaerobic resin infiltrant and modified silicate impregnant or ordinary resin-based infiltrant can also replace it. Between the casting and the cover, it uses a rubber to seal. When the hood was pumped into a vacuum, due to the role of pressure difference, infiltration solution to infiltrate and fill the casting porosity. Once the infiltration liquid dripping into the bottom of stainless steel casting, the vacuum can be released. Before sealing and after curing, the casting needs to be cleaned. 2) Vacuum pressure infiltration: After being treated (decontamination, cleaning, degreasing, drying) the leakage castings after being sealed need to be vacuumized to remove the gas, moisture, dust in the holes of casting caused by defects to eliminate air cushion effect when increasing pressure. Then, fulfill the container with infilrant and let it fill in the tiny holes under pressure differences. Next fulfill the container with compressed air to further make infilrant penetrate into depth of tiny hole. At last, the pressure infiltration is finished. More parfect casting foundry news , welcome to visit website :https://www.casting-forgings.com to know more