能力 に 耐える 摩耗 および 抵抗 くぼみ ある 2 非常に 重要 属性 の 特定の タイプ の 金属。いつ selecting a type of metal, one important factor to take into account is its hardness, which is a measurement of those properties. The outermost surface of a metal is arguably the most crucial part to determine the ideal hardness for. This is due to the fact that it is the surface that gets directly hit and abraded the most. Some metals undergo a process called case hardening to change their surface hardness 注文 に 保証 それ 硬度 の a 金属 基質 は 適しています。
What Is Case Hardening?
ケース 硬化 is a heat treatment process that hardens the surface of a metal substrate while maintaining a softer core. This allows to combine the best properties of a soft and hard metal into one part.
比較 に a 硬質 物質, a ソフト 材料 缶 耐える 衝撃 圧力 遠い より良い. さらに, it is stronger, more 延性, and tougher, but its wear resistance is insufficient. To make sure that the material does not wear away from abrasion or friction, good wear resistance is essential. We can greatly minimize material wearing without sacrificing other quality by only hardening the exterior.
A thin, hardened surface can be obtained in a variety of ways, including by adding additional components to the surface or by changing the crystal structure. but high temperatures are nearly always needed for case hardening, regardless of the method.
There are several reasons to case harden a material rather than attempt to harden an entire metal object. One reason is efficiency. Less energy and less time are required to heat the outermost surface of a metal as opposed to its entire cross section. These efficiencies can result in huge cost savings in large-scale manufacturing operations. Another reason why case hardening is widely used is because of performance. It can be advantageous to have a metal with a hard outside shell and a more ductile interior. An example of this would be when a metal is needed to resist abrasion, but still needs to be able to absorb an impact without resulting in a complete brittle fracture.
Types of ケース 硬化 方法
The case hardening principle is pretty straightstraight. We want the surface to form a hard structure known as martensite. But this structure forms only when steel components are quenched at high temperatures and provided that the carbon content of steel alloy is high enough.
If the carbon content is sufficient, we only need to heat and quench the part. But if the carbon content is low or if we need extreme hardness, elements such as carbon and nitrogen need to be added to the material's surface. Let's now look at the different processes used to achieve case hardening based on the above-mentioned principles.
加熱 および 焼入れ
Traditionally, heating and quenching have been used to carry out hardening in a range of metals. One method of case-hardening metal is to apply a direct oxy-gas flame to the steel component. The usage of inductive heating occurs occasionally. The steel part's surface temperature rapidly increases in both scenarios. As a result, austenite crystal structure replaces pearlite crystal structure.
Once a set temperature is reached, the part is cooled rapidly, often by immersing it in water. This alters the crystal structure once again, this time from austenite to martensite which is a particularly hard structure.
since only the surface undergoes the change in the crystal structure, the part hardens only at the surface. But in order for the part to benefit from this method, there must be enough carbon in the original material. In the case of low carbon content (<0.3%) in the metal part, this method will not yield favourable results.
浸炭剤
If the carbon levels are below 0.3%, we must add more carbon to the part before subjecting it to heating + quenching. Putting a part through the carburising process is one way to do that.
浸炭 巻き込み 加熱 鋼 部品 a あらかじめ決められた 期間 の 時間 間 外側 炭素 源 is present. The carbon from the carbonaceous substance diffuses into the metal at high temperatures. More heat and longer heating times cause carbon to be absorbed into the metal surface more deeply.
窒 化
のため a steel alloy that contains elements such as aluminium, chromium and molybdenum, we can use nitriding for case hardening。
part is heated in the presence of nitrogen gas and dissociated ammonia to form nitrides. The nitrides. The nitrides also increase the hardness of the material.
以来 the item is heated to 620 degree (1150 degree F), nitriding usually occurs at lower temperatures. The diffusion and ensuring hardness will be deeper the longer it is maintained at this temperature.
何 種類 金属 缶 Be ケース 硬化?
金属 それ 缶 ある ケース 硬化 ある 一般的に 限定 に 鉄 材料, although there are special cases such as the nitriding of some titanium or aluminum alloys. The ferrous metals commonly case hardened are:
低炭素 炭素 鋼
高 炭素 鋼
鋳物 鉄
高 強度 低 合金 鋼
工具 鋼
ステンレス スチール
一部 共通 コンポーネント that are case hardened include:
歯車
ファスナー
カムシャフト
棒
ピン
