An Important Step in Heat Treatment of Precision Castings
For the needed mechanical, physical & chemical property during the precision casting , Except the selection of suitable materials and various techniques, heat treatment is essential. Steel is most widely used material in the machinery industry. Its microstructures are very complex and can be controlled through the heat treatment, so heat treatment for steels is the main part of metal heat treatments.
In addition, aluminum, copper, magnesium, titanium and its alloy can also change its mechanical, physical and chemical properties by heat treatment, in order to get different properties. Bulk heat treatment is heating the cast iron platform or precision casting entirely and then cooling with suitable speed. It is a kind of metal heat treatment that changes the entire mechanical property of the cast iron platform or precision casting.
At present, there are four basic techniques of the heat treatment, annealing, normalizing, quenching and tempering in China. Tempering techniques should be strictly followed in the tempering process and rib plate intensive part or easily deformed parts should be added the supporting ribs so as to prevent the deformation & breakage because of the tempering temperature. And tempering furnace should be watched and especially cared in order to prevent the temperature in too high or too low position, thus not affecting the heat treatment workpieces.
Precision casting parts after the ageing treatment can improve its performance and internal quality. Metal heat treatment has been an important process in the machinery manufacturing, compared to other processes. Heat treatment doesn’t change the sharpe and integral chemical composition of the workpiece and instead, by changing the internal microstructure or chemical composition of the precision casting parts’ surface or cast iron platform.. Its characteristic is to improve the internal quality of cast iron platform and casting parts.
