Development Of The New Material And Study Of Confectioning Process Of Grinded Paste Machine Cylinder

Firstly, microstructure and composition of screwy sheath's material is analyzed by making use of scanning electron microscope (SEM), digital metallographic microscope and other analysis methods. Then proposal of new material research is put forward. Secondly, research of new material of the NMS cast iron is carried out by method of contrast experiment. Influence rule of microstructure and performance of NMS cast iron is studied when different mass fraction Ni, C is added. The results show that: the content of the austenite increases continually and the hardness increases firstly and then declines with the increasing of Ni when the content of Cr and C is invariable. When the content of Ni is 4%, the hardness reach the vertex, NMS cast iron resistant wearing reach the vertex, resistant corrosion reach the vertex too. The toughness of the NMS cast iron increases firstly and then it decline with the increasing of content of Ni. The toughness of the NMS cast iron is the best when the content of Ni is 6%. The amount of the carbide of the NMS cast iron increases, the hardness increases, resistant wearing promotes but the toughness declines and the corrosion of the NMS cast iron increases firstly and then it declines with the increasing of C when the content of Cr and Ni is invariable. The corrosion is better when the content of C is 2.8%. Further more, the centrifugal casting process of producing double spiral roller grinded-paste machine is explored by making use of NMS cast iron. Dope selection, mould temperature and mould rotational speed is studied. The results show that: dope thickness and brushing process influence directly microstructure of casting surface, air hole and inclusion deficiency, the thickness of the dope should be controlled between 2.0mm and 3.0mm, the coating should adopt the spraying process of the airbrush; the mould temperature should be controlled about at 450 ℃, and when the temperature of the mould is too low, the casting is apt to present the deficiency of cold shut and crack. The rotational speed is the most important factor of affecting the quality of castings. Castings appear the deficiency of drop when the rotational speed is low. When rotational speed is high, casting cooling speed is fast and castings are apt to produce deficiency of layer, the rotational speed should be controlled at 1400r/min. Microstructure of centrifugal castings gets fine, orientation growth and consistence of microstructure is a lot higher than that of ordinary sand mould castings. Much dimple is found in the fracture, the toughness of castings is improved a lot. At last, cylinder of double spiral roller grinded-paste machine is produced by centrifugal casting. Experiment results show that lifespan is treble longer than that of traditional material and cost is equal to that of traditional material.