The cost of heat treatment through the selection of appropriate quenching media for NF6357A cast alloy for wear resistance application can be reduced significantly. Forced Air cooled is the cheapest and most environmental friendly mean of quenching recommended for all casting of this composition provided the section thickness is within 50 to 120 mm. Castings thicker than 120 mm should be quenched in oil to avoid hardness and microstructural changes, which in turn will affect the wear resistance of NF635A composition
It is recommended that all alloy compositions be evaluated on the basis of the findings from Figure 2, so that appreciate and suitable heat treatment temperature can be established. By so doing, residual austenite measurements can then be carried out as a matter of routine quality control in the foundry