Method for integrally casting large-sized V-shaped diesel engine body by utilizing nodular cast iron

Abstract

The invention discloses a method for integrally casting a more-than-25-ton large-sized diesel engine V-shaped body by utilizing nodular cast iron. The method comprises the following steps of A1, smelting the nodular cast iron in a smelting furnace, and adding bariumsili and metallurgical carborundum pretreatment agent after the smelting; A2, placing a spheroidizing agent into a bottommost layer of a dam-type spheroidizing ladle, utilizing a nucleating agent to cover a second layer, and utilizing a low-maganese low-alloy broken steel sheet to completely cover and compact a third layer; A3, adding a calcium-barium nucleating agent, charging the melted iron in one step to carry out the tapping metal-stream inoculation, realizing the nucleating effect while carrying out the spheroidizing treatment on charged melted iron, and carrying out the pouring pretreatment on the melted iron in the ladle; A4, placing the metal-stream inoculation agent into a funnel to carry out the pouring metal-stream inoculation; and A5, finally pouring the melted iron with the temperature being more than or equal to 1400 DEG C into a sand box, forming a cast by mold filling and solidifying the melted iron under the feeding of the feeder head liquid metal, and carrying out the heat treatment by utilizing the waste heat of the cast.

Description

technical field [0001] The invention belongs to the technical field of a production method of a large-scale diesel engine integrally cast body, and in particular relates to an integral casting method for manufacturing a V-shaped diesel engine body of 25 tons or more by using nodular cast iron. Background technique [0002] Large diesel engines are mainly used in ship propulsion power plants and ship power stations in the shipbuilding industry. At present, my country has become a veritable country in the shipbuilding industry. With the further deepening of global trade integration, the shipping industry will continue to develop rapidly in the future and drive the rapid development of the shipbuilding industry and its supporting products. The demand for supporting equipment for the shipbuilding industry continues to be strong. Among the supporting equipment, the value of the key component - diesel engine accounts for about 13% to 20% of the value of the whole ship, so the mar...

AI Technical Summary

Problems solved by technology

Although the market demand for diesel engines is strong, many foundries are unable to produce large engine bodies over 20 tons due to the technical difficulty in developing and producing large diesel engine blocks, high equipment requirements, and high risk factors.

Although our country has formed a certain production capacity, but in terms of engine body type, V-type body is a development trend. For each ton of cast iron body, V-type body can be equipped with 50% more cylinders than straight-line ones. This not only saves costs, but also greatly improves engine efficiency, but few manufacturers in China try to independently develop V-shaped airframes, especially engine airframes over 20 tons.

[0004] At present, most diesel engine bodies in China use cast steel and steel plate cast-welded structure. This casting method has the following disadvantages: in terms of technical performance, it has poor working stability and vibration damping, and the structure of the casting is poor. Crack tendency, poor comprehensive performance; In terms of production, the manufacturing cycle is long, the production process is many, and the main bearing seat and the body steel plate welding parts need to be processed, welded and corresponding production processes

In addition, the surface quality of the casting is poor and the machining allowance is large

Images