When the tensile stress is bigger than the limits of the liquid layer strength, the content crystal would be draw away

　　During the normal production period of the wheel loader tooth pin, if the total tensile stress is bigger than the biggest strength limits of the liquid layer, then the content crystal would be draw away, so if there are some abandon metal liquid near this position, these metal liquid would flow into the draw cracks position, so under the influence of this phenomenon, the casting piece of the wheel loader tooth pin would has some heating cracks or never has some heat cracks.

　　So the wheel loader tooth pin production manufacture said the main reason causes the heat cracks happen is because the parts can be fully and uniform shrink during the deformation period, so during the part mold filling period, production manufacturer need to ensure the temperature of the mold is uniform, so it can produce a very lower production pressure and can be fully shrink, so the surface of the wheel loader tooth pin would never has some cracks.