Composite manufacturing method of corrosion-resistant impeller of sea water pump

Abstract

The invention provides a composite manufacturing method of a corrosion-resistant impeller of a sea water pump. The method specifically comprises two processes of material adding and material reducing.The material adding process comprises the following steps: A1, casting a base metal by using vermicular graphite cast iron and cleaning the surface; A2, preparing a welding material, and uniformly coating the surface of the base metal with a layer of 316 L stainless steel in a deposition mode by a strip electrode electroslag surfacing method till the external dimension reaches the subsequent machining requirement. The material reducing process comprises the following steps: B1, planning a milling cutter path and process parameters according to the shape of a finished product, and B2, millingthe finished product through material reducing machining. The method has the technical advantages that process operation is simple, production automation is convenient to realize, universality is high, and the method can be applied to manufacturing other parts; the performance advantages of high strength of the vermicular graphite cast iron and strong corrosion resistance of the 316 L stainless steel are fully combined, and the manufactured finished product has the characteristics of high strength and corrosion resistance; and meanwhile, the strip electrode electroslag surfacing is mainly adopted to deposit corrosion-resistant alloy, and the defect of the large dilution rate of an MIG additive manufacturing method is overcome.

Description

technical field [0001] The invention relates to the technical field of seawater pumps, in particular to a compound manufacturing method for corrosion-resistant impellers of seawater pumps. Background technique [0002] Seawater pump is a kind of machine that transmits the mechanical energy of the motor to seawater. It is widely used in coastal firefighting, seawater desalination, and offshore equipment cooling. As one of the flow-passing parts, the impeller of the seawater pump is in the state of being washed by the flow of seawater for a long time, and the impeller is extremely vulnerable to electrochemical corrosion and Cl - Pitting damage. The existing technology mainly adopts vermicular graphite cast iron precision casting impeller, and its main disadvantages are: (1) limited by the casting process itself, there is a certain draft angle in the shape of the parts, which makes it difficult to carry out chamfering, fine milling and other processing directly according to th...

AI Technical Summary

Problems solved by technology

The existing technology mainly adopts vermicular graphite cast iron precision casting impeller, and its main disadvantages are: (1) limited by the casting process itself, there is a certain draft angle in the shape of the parts, which makes it difficult to carry out chamfering, fine milling and other processing directly according to the design size; (2) The manufacturing process of the mold is difficult, the degree of automation is low, and it is inconvenient to modify; (3) Although the commonly used material vermicular graphite cast iron has good castability and high strength, it has high carbon content and poor seawater corrosion resistance

The main disadvantages of this method are: the heat source of the MIG method is an electric arc, the energy density is concentrated, the splash is violent during the surfacing process, and the dilution rate of the surfacing layer after welding is large (often up to 20%)

However, domestic research on strip electroslag surfacing has just started, the types of commercially available fluxes are limited and most of them are imported products, and the research on process parameters is also very limited, which hinders the application of this process in the field of composite manufacturing to a certain extent.

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