Bimetal plunger pump cylinder body extrusion casting forming method

Abstract

The invention discloses a bimetal plunger pump cylinder body extrusion casting forming method, and relates to the technical field of bimetal extrusion forming preparation. Firstly, in the preheating stage, a steel substrate is placed in an extrusion die, an induction coil heats the steel substrate to 1130-1170 DEG C, a liquid copper alloy with the temperature being 1150-1250 DEG C is injected into the steel substrate, standing and cooling are carried out at the room temperature to 750-900 DEG C, and then in the semi-solid extrusion stage, lower and upper timed and partitioned extrusion is conducted, and a lower punch upwards conducts semi-solid extrusion so that a copper alloy valve plate copper layer at the lower end of a plunger pump cylinder body can be extruded and formed. After a valve plate of a cylinder body is formed, an upper punch begins to downwards extrude a riser at the upper end of the cylinder body, and a plunger and a kidney-shaped hole of the cylinder body are formed. The bimetal cylinder body prepared through the bimetal plunger pump cylinder body extrusion casting forming method is free of interface cracking and high in bonding strength, and the copper alloy structure is compact, fine and uniform.

Description

technical field [0001] The invention relates to the technical field of bimetal extrusion molding preparation, in particular to a bimetal plunger pump cylinder block extrusion casting molding method. Background technique [0002] Bimetal plunger pump cylinder is an important device of hydraulic system, and has a wide range of application prospects in many fields. The plunger pump cylinder is composed of two parts: the main part is usually made of low carbon steel, which plays the role of bearing pressure and resisting impact; the working surface is made of wear-resistant tin bronze, which is composed of the plunger hole wall uniformly distributed around the circumference and the bottom distribution plate It has the characteristics of anti-fatigue, anti-friction and good thermal conductivity. The bonding quality of the bimetallic interface mainly depends on the bonding strength of the interface, and the microscopic morphology of the interface and the compactness of the copper...

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Problems solved by technology

[0005] 2. "Heating and Cooling Method for Melting and Casting of Steel-Copper Bimetallic Cylinder" (Application No.: CN110434315 A) The bimetallic cylinder was prepared by melting and casting. During the staged heating process in the preheating zone, the copper alloy at the interface gradually melts, but it is easy to form local defects such as pores and inclusions, and the metallurgical bonding of the entire contact surface cannot be achieved.

[0006] 3. "Technical Characteristics of Bimetallic Extrusion Casting and Hanging Forming of High-Pressure Piston Pump Rotor" reported the extrusion molding process of the cylinder body. The author used solid-liquid casting and semi-solid extrusion to form the bimetal interface, but did not The preheated steel matrix is ​​very prone to cold shut at the interface

Pouring the copper alloy liquid into the steel matrix will produce a large cooling rate. Although very fine grains will be formed at the interface, the interface temperature is low and cannot promote the diffusion of Fe / Cu atoms. Even if the interface without preheating is realized It is impossible to form a high-strength interfacial diffusion layer without defects

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