阅读说明：本技术 一种高韧性气动阀及其加工工艺 (High-toughness pneumatic valve and processing technology thereof ) 是由 刘瑞 刘奎新 王璐 陈国瑞 孙同昂 于 2020-06-15 设计创作，主要内容包括：本发明公开了一种高韧性气动阀及其加工工艺,该高韧性气动阀由如下质量百分比原料制成：碳：3.2-3.6％、硅1.5-2.8％、锰0.3-0.5％、镉0.35-0.55％、钼0.25-0.43％、铜0.8-1.5％、镁0.04-0.06％、镍0.5-0.8％、磷≤0.03％、硫≤0.15％,余料为铁；将原料进行熔炼制得原铁液,再将球化剂和孕育剂加入球化包中并进行预热,使得原铁液球化孕育的效率提升,且多次升温和降温使得球墨铸铁制件的内部受热均匀,并促进了球墨铸铁制件表面提升硬度的微观组织生长,防止了组织转变时应力过大引发球墨铸铁制件表面出现裂痕,并进行回火使得球墨铸铁制件的性能进一步提升,在回火后冷却使得球墨铸铁制件表面达到最佳状态,进而使得气动阀具有很高的冲击韧性,进而提升气动阀的使用寿命。(The invention discloses a high-toughness pneumatic valve and a processing technology thereof, wherein the high-toughness pneumatic valve is prepared from the following raw materials in percentage by mass: carbon: 3.2 to 3.6 percent of silicon, 1.5 to 2.8 percent of silicon, 0.3 to 0.5 percent of manganese, 0.35 to 0.55 percent of cadmium, 0.25 to 0.43 percent of molybdenum, 0.8 to 1.5 percent of copper, 0.04 to 0.06 percent of magnesium, 0.5 to 0.8 percent of nickel, less than or equal to 0.03 percent of phosphorus, less than or equal to 0.15 percent of sulfur and the balance of iron; the raw materials are smelted to prepare the original molten iron, and then a nodulizer and an inoculant are added into a nodulizing ladle and preheated, so that the nodulizing efficiency of the original molten iron is improved, the interior of a nodular cast iron part is heated uniformly by heating and cooling for many times, the microstructure growth of the surface of the nodular cast iron part for improving the hardness is promoted, cracks are prevented from appearing on the surface of the nodular cast iron part due to overlarge stress when the structure is changed, tempering is carried out, the performance of the nodular cast iron part is further improved, the surface of the nodular cast iron part reaches the best state after tempering by cooling, the pneumatic valve is made to have very high impact toughness, and the service life of the pneumatic valve is prolonged.)

1. A high toughness pneumatic valve characterized by: the material is prepared from the following raw materials in percentage by mass: carbon: 3.2 to 3.6 percent of silicon, 1.5 to 2.8 percent of silicon, 0.3 to 0.5 percent of manganese, 0.35 to 0.55 percent of cadmium, 0.25 to 0.43 percent of molybdenum, 0.8 to 1.5 percent of copper, 0.04 to 0.06 percent of magnesium, 0.5 to 0.8 percent of nickel, less than or equal to 0.03 percent of phosphorus, less than or equal to 0.15 percent of sulfur and the balance of iron.

2. A high toughness pneumatic valve as claimed in claim 1, wherein: the pneumatic valve is manufactured by the following steps:

step A1: adding the raw materials into a medium-frequency induction furnace, and smelting at the temperature of 1500-;

step A2: putting a nodulizer into a nodulizing ladle, adding an inoculant to cover the nodulizer, heating the nodulizing ladle at the temperature of 800-;

step A3: pouring the spheroidized iron liquid prepared in the step A2 at the temperature of 1480-1500 ℃ to prepare a nodular cast iron part;

step A4: and D, preserving the heat of the nodular cast iron part prepared in the step A3 for 2-2.5h at the temperature of 950-.

3. A high toughness pneumatic valve as claimed in claim 2, wherein: the inoculant in the step A2 is one of a ferrosilicon inoculant and a silicon-barium inoculant, the dosage of the inoculant is 0.8-1.5% of the total mass of the added raw materials, and the particle size of the inoculant is 1.5-3 mm.

4. A high toughness pneumatic valve as claimed in claim 2, wherein: the nodulizer in the step A2 is one of a low-magnesium nodulizer with the magnesium content of 4%, a low-magnesium nodulizer with the magnesium content of 5% and a low-magnesium nodulizer with the magnesium content of 5.5%, and the dosage of the nodulizer is 1.5-2.5% of the total mass of the added raw materials.

5. The process of claim 1 wherein said at least one high toughness pneumatic valve is selected from the group consisting of: the method specifically comprises the following steps:

step A1: adding the raw materials into a medium-frequency induction furnace, and smelting at the temperature of 1500-;

step A2: putting a nodulizer into a nodulizing ladle, adding an inoculant to cover the nodulizer, heating the nodulizing ladle at the temperature of 800-;

step A3: pouring the spheroidized iron liquid prepared in the step A2 at the temperature of 1480-1500 ℃ to prepare a nodular cast iron part;

step A4: and D, preserving the heat of the nodular cast iron part prepared in the step A3 for 2-2.5h at the temperature of 950-.

Technical Field

The invention belongs to the technical field of pneumatic valves, and particularly relates to a high-toughness pneumatic valve and a processing technology thereof.

Background

The pneumatic valve is driven by compressed air, the main raw material of the pneumatic valve is nodular cast iron, the cast iron is an iron-carbon alloy, and is characterized in that the carbon content is high, the mass percentage of the carbon element is more than 2%, the pneumatic valve also contains more impurity elements such as silicon, manganese, phosphorus, sulfur and the like, most of the impurity elements spread in the cast iron exist in the form of carbide or free graphite, and a small amount of graphite which is dissolved in ferrite exists, the graphite lattice type in the cast iron is simple hexagonal lattice, the atomic distance in a basal plane is 0.142nm, the binding force is strong, but the surface distance between the two basal planes is 0.340nm, the binding force is weak, so that the basal plane of the graphite is easy to slide, the strength, the hardness, the plasticity and the toughness are extremely high, the graphite in the nodular cast iron is spherical, the strength and the toughness are higher than other cast irons such as gray cast iron, and the pneumatic valve has excellent castability and high damping property at the, Good machinability and relatively low price compared with steel with similar performance, so that the wear-resistant parts such as crankshafts, camshafts, hot rolls and the like are widely applied in industry, and the wear-resistant parts are often made of nodular cast iron, and the dosage of the wear-resistant parts in the manufacturing industry is the second place of all metal materials. Ductile iron, also known as ductile iron, has graphite that acts as a crack stopper, giving it excellent properties of human and ductility.

The current pneumatic valve is after long-time the use, because self receives the environmental impact for a long time, self fragility constantly increases, and toughness reduces, and the reduction of toughness can make the pneumatic valve appear warping at the pneumatic valve even surface appearance crackle for the unable normal work of pneumatic valve, and current pneumatic valve life is lower.

Disclosure of Invention

The invention aims to provide a high-toughness pneumatic valve and a processing technology thereof.

The technical problems to be solved by the invention are as follows:

the current pneumatic valve is after long-time the use, because self receives the environmental impact for a long time, self fragility constantly increases, and toughness reduces, and the reduction of toughness can make the pneumatic valve appear warping at the pneumatic valve even surface appearance crackle for the unable normal work of pneumatic valve, and current pneumatic valve life is lower.

The purpose of the invention can be realized by the following technical scheme:

a high-toughness pneumatic valve is prepared from the following raw materials in percentage by mass: carbon: 3.2 to 3.6 percent of silicon, 1.5 to 2.8 percent of silicon, 0.3 to 0.5 percent of manganese, 0.35 to 0.55 percent of cadmium, 0.25 to 0.43 percent of molybdenum, 0.8 to 1.5 percent of copper, 0.04 to 0.06 percent of magnesium, 0.5 to 0.8 percent of nickel, less than or equal to 0.03 percent of phosphorus, less than or equal to 0.15 percent of sulfur and the balance of iron.

Further, the pneumatic valve is manufactured by the following steps:

step A1: adding the raw materials into a medium-frequency induction furnace, and smelting at the temperature of 1500-;

step A2: putting a nodulizer into a nodulizing ladle, adding an inoculant to cover the nodulizer, heating the nodulizing ladle at the temperature of 800-;

step A3: pouring the spheroidized iron liquid prepared in the step A2 at the temperature of 1480-1500 ℃ to prepare a nodular cast iron part;

step A4: and D, preserving the heat of the nodular cast iron part prepared in the step A3 for 2-2.5h at the temperature of 950-.

Further, the inoculant in the step A2 is one of a ferrosilicon inoculant and a silicon-barium inoculant, the dosage of the inoculant is 0.8-1.5% of the total mass of the added raw materials, and the particle size of the inoculant is 1.5-3 mm.

Further, the nodulizer in the step A2 is one of a low-magnesium nodulizer with a magnesium content of 4%, a low-magnesium nodulizer with a magnesium content of 5% and a low-magnesium nodulizer with a magnesium content of 5.5%, and the dosage of the nodulizer is 1.5-2.5% of the total mass of the added raw materials.

Further, the processing technology of the high-toughness pneumatic valve specifically comprises the following steps:

step A1: adding the raw materials into a medium-frequency induction furnace, and smelting at the temperature of 1500-;

step A2: putting a nodulizer into a nodulizing ladle, adding an inoculant to cover the nodulizer, heating the nodulizing ladle at the temperature of 800-;

step A3: pouring the spheroidized iron liquid prepared in the step A2 at the temperature of 1480-1500 ℃ to prepare a nodular cast iron part;

step A4: and D, preserving the heat of the nodular cast iron part prepared in the step A3 for 2-2.5h at the temperature of 950-.

The invention has the beneficial effects that: in the process of preparing the high-toughness pneumatic valve, the invention meets the performance requirement of a ductile cast iron product by controlling the content ratio of each component, further ensuring the high toughness of the pneumatic valve, firstly smelting the raw materials to prepare the raw iron liquid, then adding the nodulizer and the inoculant into a nodulizing ladle and preheating, the nodulizing inoculation efficiency of the original iron liquid is improved, and the interior of the nodular cast iron part is heated uniformly by heating and cooling for many times, promotes the growth of microstructure on the surface of the nodular cast iron product to improve the hardness, prevents cracks from appearing on the surface of the nodular cast iron product caused by overlarge stress during the transformation of the microstructure, and further improves the performance of the nodular cast iron product by tempering, after tempering, the surface of the nodular cast iron part is cooled to reach the optimal state, so that the pneumatic valve has high impact toughness, and the service life of the pneumatic valve is prolonged.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.