Carbide-carrying austempered ductile iron and quenching technology thereof

A technology of austempering ductile iron and austempering, which is applied in the field of heat treatment of metal materials, can solve the problems of high production cost, low toughness, and low productivity, and achieve the effects of good processing performance, good mechanical properties, and low safety cost

Active Publication Date: 2013-09-25
高州创建铸造有限公司
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  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

If the current austempered ductile iron is used to manufacture such structural parts as the impeller and pump casing of the impurity pump, the hardness, wear resistance and corrosion resistance are still insufficient, and further improvement and improvement are still needed to meet the requirements of the impurity pump. The need for higher performance of such structural parts as the flow parts
[0004] Moreover, the traditional austempering ductile iron needs to add expensive molybdenum (Mo) and nickel (Ni) to greatly increase its price
In the traditional nitrate salt bath isothermal quenching process, not only will a large amount of nitrite harmful substances be produced when nitrate is melted, which will seriously pollute the environment and endanger human health, but also the nitrate will melt during the isothermal quenching process. and austempering for a long time, resulting in low productivity and high production costs
[0005] Chinese invention patent (patent number 200910088451.4) discloses "an austempering nodular iron plowshare with carbides and its production method". The main technical pro

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  • Carbide-carrying austempered ductile iron and quenching technology thereof

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0085] A kind of austempering ductile iron with carbides in this embodiment includes the following components in weight percentage,

[0086] C 3.3 ~ 3.8%

[0087] P 0.01~0.05%

[0088] S 0.005~0.02%

[0089] Mg 0.025 ~ 0.045%

[0090] Re 0.015 ~ 0.03%

[0091] Sn 0.1~0.8%

[0092] Si 2.8~~3.6%

[0093] Mn 1.5~2.8%

[0094] Cr 0.2~0.8%

[0095] B 0.02~0.08%

[0096] The rest is Fe.

[0097] The present invention adjusts the chemical element composition of the austempering ductile iron with carbides to make it In Mn, Si alloy Basically, it contains 0.1~0.8% of Sn, 2.8~3.5% of Si, and 0.2~0.8% of Cr. Due to the addition of appropriate amount of Cr and B, it can properly adjust the carbide content during heat treatment and improve wear resistance and hardenability. At the same time, compared with the existing technology, a small amount of Sn and Si content is added, so that Sn and Si jointly increase the potential of the substrate electrode, and together with Cr form a ...

Embodiment 2

[0115] A kind of austempering nodular iron with carbides of the present invention comprises the following components by weight percentage,

[0116] C 3.5~3.7%

[0117] P 0.02~0.03%

[0118] S 0.005~0.01%

[0119] Mg 0.03~0.04%

[0120] Re 0.02~0.025%

[0121] Sn 0.3~0.5%

[0122] Si 3.0~3.2%

[0123] Mn 1.9~2.1%

[0124] Cr 0.4~0.6%

[0125] B 0.02~0.07%

[0126] RE-B 0.1~0.3%

[0127] The rest is Fe.

[0128] The above-mentioned RE-B is a rare earth-boron composite modifier, and its components are common knowledge in the field, and will not be described in detail here. The austempering ductile iron with carbides of the present invention adds a rare earth-boron composite modifier (RE-B) to inoculate and modify the carbides in the workpiece, which can effectively reduce the brittleness of the product and ensure its sufficient strength and proper toughness , to further increase the wear resistance.

[0129] The matrix structure of the austempering ductile iron with car...

Embodiment 3

[0143] A kind of austempering nodular iron with carbides of the present invention comprises the following components by weight percentage,

[0144] C 3.6%

[0145] P 0.0253%

[0146] S 0.008%

[0147] Mg 0.035%

[0148] Re 0.022%

[0149] Sn 0.4%

[0150] Si 3.1%

[0151] Mn 2.0%

[0152] Cr 0.5%

[0153] B 0.04%

[0154] RE-B 0.2%

[0155] The rest is Fe.

[0156] The main technical solutions of this embodiment are basically the same as those of Embodiment 1 or Embodiment 2, and the features not explained in this embodiment are explained in Embodiment 1 or Embodiment 2, and will not be repeated here.

[0157] The matrix structure of the austempering ductile iron with carbides is composed of the following components by weight percentage:

[0158] Lower bainite 50~68%

[0159] Tempered martensite 20~30%

[0160] Eutectic carbide 10~28%

[0161] Carbon-rich austenite 2~9%.

[0162] Simultaneously, a kind of band carbide austempering ductile iron quenching process ...

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Abstract

The invention relates to a carbide-carrying austempered ductile iron and a quenching technology thereof. Cr and B are added to an Mn-Si alloy, the carbide amount is properly increased, and inoculating deterioration treatment is carried out by using RE-B, so the carbide becomes a fine uniformly-distributed agglomerate to improve the hardness, the abrasion resistance, the hardenability and the toughness; and the addition of Sn and the increase of the Si amount are carried out to improve the potential of a matrix electrode, and the added Sn and the increased Si form a surface passivating film together with Cr to improve the corrosion resistance. The quenching technology of the carbide-carrying austempered ductile iron is step austempering and is characterized in that an austempered workpiece undergoes first-step austempering by using grading quenching oil to avoid the generation of pearlite, and then second-step austempering is carried out at a proper temperature in an air isothermal furnace to obtain a proper amount of fine lower bainite, increase the amount of tempered martensite, and improve the hardness and the abrasion resistance, so the carbide-carrying austempered ductile iron having the advantages of high strength and hardness, appropriate toughness, strong abrasion and corrosion resistances, good processing properties, easy precision guarantee and low cost is obtained.

Description

technical field [0001] The invention relates to the technical field of heat treatment of metal materials, in particular to an austempering ductile iron with carbides and a quenching process thereof. Background technique [0002] In the prior art, many parts and components of fluid machinery have special requirements, such as the impeller of the impurity pump, the pump casing and other flow-passing parts that need to be machined and require high precision, high hardness, high strength and appropriate toughness. Structural parts, this is because such structural parts usually operate in working conditions containing similar hard particles and corrosive media such as quartz sand, so that such structural parts are often scrapped due to wear or corrosion. If stainless steel and high-nickel corrosion-resistant cast iron are used to manufacture such structural parts, although they can meet the requirements of corrosion resistance, the hardness and strength of these materials are low...

Claims

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Application Information

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IPC IPC(8): C22C37/06C22C37/04C22C33/08C21D5/00
Inventor 不公告发明人
Owner 高州创建铸造有限公司
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