Machining method for modifying spheroidal graphite cast iron well lid

Abstract

The invention relates to a machining method for modifying a spheroidal graphite cast iron well lid. The machining method is characterized in that modification is carried out with an alloying means, the micro-structure of spheroidal graphite cast iron can be improved, and the mechanical performance of the spheroidal graphite cast iron can be further improved. A powder spheroidizing agent is adoptedfor spheroidizing treatment, the absorption rate is obviously increased, and the production cost can be reduced. A nucleating agent is added step by step, so that the nucleating effect is improved.

Description

technical field

[0001] The invention relates to the field of processing ductile iron manhole covers, and mainly relates to a processing method for a modified nodular cast iron manhole cover. Background technique

[0002] With the rapid development of modern science and technology and social economy, urban construction is gradually accelerating, and the scale of the city is constantly expanding. Various road facilities have gradually entered into standardized and standardized management. The market demand in construction is increasing. Since the manhole cover is a closure leading to the top of the entrance and exit of underground facilities, all urban roads, highways, tap water, drainage, telecommunications, electricity, fire hydrants, valves and other public facilities need to install manhole covers. Most of the materials used for manhole covers used to be reinforced concrete, but due to the defects of high brittleness, easy aging, and easy fracture of reinforced concrete, ...

Examples

Embodiment 1

[0012] A processing method for a modified nodular cast iron manhole cover is characterized in that it is made by the following steps:

[0013] 1) Add pig iron and scrap steel to the furnace for complete melting, add 0.5% Cu and 0.02% Sb for modification, until completely melted, then add silicon barium inoculant accounting for 0.5% of molten iron for the first inoculation treatment;

[0014] 2) Use the flushing method to add powder rare earth spheroidizer for spheroidization. Before spheroidization, preheat the spheroidization bag with molten iron for 5 minutes, and put the powder rare earth spheroidizer accounting for 1% of the mass of molten iron into the On one side of the spheroidizing bag dam, cover a layer of silicon-barium inoculant accounting for 0.3% of the mass of molten iron, and then cover a layer of low-carbon steel small iron sheet accounting for 0.5% of the mass of molten iron, and sprinkle a layer of slag on it. After pouring molten iron, cover the spheroidizin...

technical field

[0001] The invention relates to the field of processing ductile iron manhole covers, and mainly relates to a processing method for a modified nodular cast iron manhole cover. Background technique

[0002] With the rapid development of modern science and technology and social economy, urban construction is gradually accelerating, and the scale of the city is constantly expanding. Various road facilities have gradually entered into standardized and standardized management. The market demand in construction is increasing. Since the manhole cover is a closure leading to the top of the entrance and exit of underground facilities, all urban roads, highways, tap water, drainage, telecommunications, electricity, fire hydrants, valves and other public facilities need to install manhole covers. Most of the materials used for manhole covers used to be reinforced concrete, but due to the defects of high brittleness, easy aging, and easy fracture of reinforced concrete, ...

Examples

Embodiment 1

[0012] A processing method for a modified nodular cast iron manhole cover is characterized in that it is made by the following steps:

[0013] 1) Add pig iron and scrap steel to the furnace for complete melting, add 0.5% Cu and 0.02% Sb for modification, until completely melted, then add silicon barium inoculant accounting for 0.5% of molten iron for the first inoculation treatment;

[0014] 2) Use the flushing method to add powder rare earth spheroidizer for spheroidization. Before spheroidization, preheat the spheroidization bag with molten iron for 5 minutes, and put the powder rare earth spheroidizer accounting for 1% of the mass of molten iron into the On one side of the spheroidizing bag dam, cover a layer of silicon-barium inoculant accounting for 0.3% of the mass of molten iron, and then cover a layer of low-carbon steel small iron sheet accounting for 0.5% of the mass of molten iron, and sprinkle a layer of slag on it. After pouring molten iron, cover the spheroidizin...