Experimental Investigation On Metallurgical Quality Of JX4D30 Cylinder Block

As a key component of engine, the cylinder-block is a typical complex casting with thin wall. During the engine operation, the cylinder-block suffers from circulate shock of high temperature and high gas Pressure. Therefore, the casting of the cylinder-block must have a high quality. The JX4D30 engine is a new type engine which will be put into operation recently by Jiangling's company. This paper is based on the casting of the cylinder-block, discussing the influential rule of Cu, Cr, Sn's content and addition of stream inoculant on structure and property, a comprehensive and valuable analysis was made between mechanical property and material cost.The experiment rests show that the content of Sn has the topmost influence on the tensile strength of grey iron, it is the most importance factor, the maximum tensile strength can be achieved when the content of Sn is about 0.06%; the content of Cu and the content of Cr are next in importance factor, the content of Cu and the content of Cr have the same influence on the tensile strength of grey iron, the maximum tensile strength can be achieved when the content of Cu is about 0.62%, the maximum tensile strength can be achieved when the content of Cr is about 0.29%; the addition of stream inoculant is the least importance factor, the maximum tensile strength can be achieved when the addition of stream inoculant is about 0.10%.The experiment rests show that the content of Sn has the topmost influence on the hardness of grey iron, it is the most importance factor, the maximum hardness can be achieved when the content of Sn is about 0.10%; the content of Cu is next in importance factor, the maximum hardness can be achieved when the content of Cu is about 0.62%; the content of Cr and the addition of stream inoculant are the least importance factors, the content of Cr and the addition of stream inoculant have the same influence on the hardness of grey iron, the maximum hardness can be achieved when the content of Cr is about 0.19%, the maximum hardness can be achieved when the addition of stream inoculant is about 0.15%.Considering mechanical property, the machining property and material cost totally, this type of cylinder-block should have the composition as follows: Sn=0.05%-0.07%; Cu=0.20%-0.25%; Cr=0.16%-0.22%; the addition of stream inoculant is about 0.10%.