Effect of solidification pressure on mechanical properties of cast chromium white cast iron

The results show that the morphology and distribution of primary phase and eutectic structure in the solidification structure of chromium white cast iron are greatly changed under pressure, and the phase composition is also changed. In this chapter, the hardness, impact toughness, impact wear and other properties of chromium white cast iron under different pressure were characterized, and the effect of pressure on the mechanical properties of chromium alloy with specific composition was obtained. In addition, the influence mechanism of different pressure on the mechanical properties of the alloy will be discussed in combination with macro, micro structure and phase composition.

(1) The results show that the hardness of the two kinds of chromium white cast iron is obviously improved under the action of solidification pressure. Compared with the normal pressure, the hardness of alloy 1 increases about 17% at 170 MPa, and that of alloy 2 increases about 25% at 160 MPa. The fine grain strengthening under pressure, the increase of carbide content and the transformation of carbide type are all factors to improve the hardness of the alloy.

(2) The impact toughness of chromium white cast iron does not necessarily increase with the increase of pressure. For alloy 1, the increase of solidification pressure does not improve the impact toughness of the alloy, but further reduces it. For alloy 2, the impact toughness at 160 MPa is 1.5 times of that at normal pressure.

(3) When the solidification pressure is about 170 MPa, the impact wear resistance of the alloy is 1.5 times higher than that of the normal pressure casting; When the solidification pressure is about 160MPa, the impact wear resistance of alloy 2 ᦇ is nearly twice as high as that of normal pressure casting.

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