Finite Element Simulation of Water Spray Quenching of Large Size NM450 Steel Plate

Water spray quenching is a cost-effective cooling process that is widely used in the manufacturing industry. It is used to cool and harden parts that have been exposed to heat treatments, such as forging and brazing. The process involves spraying a high-pressure stream of water onto the part. This pressure and large amount of water enables the parts to be cooled faster and more evenly than traditional cooling methods.
    
This article will discuss the results of a finite element analysis that simulated the water spray quenching of a large size NM450 steel plate. The bulk properties of the plate were determined using tensile tests, hardness tests and microstructure analysis. The plate was then subjected to water spray quench to a temperature of 100°C at different immersion depths of 0, 10 and 20mm.
    
The finite element analysis used the ABAQUS software package to simulate the cooling process. The plate was represented as a two-dimensional solid which was kept in a horizontal position. The hydrodynamic forces of the water spray were modeled using a turbulent flow model. The convective heat transfer to the plate was modeled using a coupled finite-element fluid flow analysis.
    
NM450 steel plate the results of the analysis showed that the cooling rate of the plate decreased with an increase in immersion depth. At an immersion depth of 0mm, the cooling rate was 4.02°C/second. This rate decreased to 3.80°C/second and 3.20°C/second at 10mm and 20mm immersion depths respectively. The analysis also showed that there was a notable increase in the cooling rate near the surface of the plate.
    
In order to further improve the cooling rate of the NM450 steel plate, the finite element analysis was repeated with a more aggressive water spray. This involved increasing the water velocity of the stream from 7m/s to 8m/s and the spray rate from 25kg/minute to 34kg/minute. The results showed a considerable improvement in the cooling rate of the plate, with values of 5.37°C/second and 4.27°C/second at 10mm and 20mm immersion depths respectively.
    
From the results of the finite element analysis, it can be concluded that the cooling rate of a large size NM450 steel plate can be improved by using an aggressive water spray quench. However, in order to achieve the optimum cooling rate, the immersion depth must be taken into account.

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