什么是不锈钢的不锈钢型

比其他铁不锈钢污渍不容易-based metals, but it’s not literally “stainless”. Just like standard steel, stainless can get marked up by fingerprints and grease, develop discoloration, and eventually rust. The difference is resilience. Stainless steel can withstand much more time and abuse before showing signs of wear.

All steels have the same basic iron and carbon composition, but stainless steel also contains a healthy dose of chromium—the alloy that gives stainless steel its famous corrosion resistance.

这就是事情变得复杂的地方。不锈钢伞下有多个等级，每个级别的合金组成略有不同，因此物理特性略有不同。

不锈钢必须至少含有10.5％的铬。根据等级的不同，它可能含有更高的铬水平，以及其他合金成分，例如钼，镍，钛，铝，铜，铜，氮，磷和硒。

What is stainless steel ?

不锈钢是铁基合金，具有极大的耐腐蚀性。与其他类型的钢相比，钢至少添加至少12％的铬，它使其抵抗生锈（或）不锈钢，据观察，在不锈钢表面形成了薄，透明且非常坚韧的膜，这是惰性的或被动，不会与许多腐蚀性材料反应。在235°C至980°C的温度范围内，它表现出强度，韧性和耐腐蚀性优于其他金属。因此，它非常适合在低温温度下处理和存储液氦，氢，氮和氧气。通过仅将铬和镍一起添加（或）将腐蚀性的性质通过添加（OR）来获得。不锈钢在电炉中生产。

Why stainless steel is corrosive resistance
Stainless steels are very slightly oxidisable. Slight oxidation forms very thin film of oxide and this oxide film acts as a protective coating and in this way further corrosion is stopped. This protective film of oxide is so thin that the colour and beauty of the basic materials is not affected.

不锈钢类型

不锈钢可以分为以下组：

奥氏体不锈钢：

Austenitic steels have austenite as their primary phase. These are alloys containing atleast 24% chromium and nickel combined and the percentage of each of them alone is not less than 8%. These steels may contain other elements for particular purposes. Standard austenitic steels are vulnerable to stress corrosion cracking. Higher nickel austenitic steels have increased resistance to stress corrosion cracking. These are non-hardenable by heat treatment and non-magnetic but usually exhibit some magnetic response depending on the composition and the work hardening of the steel.

类型304

最常见的奥氏体等级，含有约18％的铬和8％的镍。它用于化学加工设备，用于食品，乳制品和饮料行业，热交换器以及温和的化学品。

类型316

Contains 16% to 18% chromium and 11% to 14% nickel. It also has molybdenum added to the nickel and chrome of the 304. The molybdenum is used to control pit type attack. Type 316 is used in chemical processing, the pulp and paper industry, for food and beverage processing and dispensing and in the more corrosive environments. The molybdenum must be a minimum of 2%.

类型317

Contains a higher percentage of molybdenum than 316 for highly corrosive environments. It must have a minimum of 3% “moly”. It is often used in stacks which contain scrubbers.

Martensitic Stainless steel
这些是铁，碳和铬合金。铬的百分比和碳百分比的差异小于12.5％。这些也称为铬钢，并且能够硬化和磁性。它们在需要高强度和中等耐腐蚀性的地方使用。它们通常具有低焊接能力和形式能力。它们是磁性的。

Type 410

Basic martensitic grade, containing the lowest alloy content of the three basic stainless steels (304, 430, and 410). Low cost, general purpose, heat treatable stainless steel. Used widely where corrosion is not severe (air, water, some chemicals, and food acids. Typical applications include highly stressed parts needing the combination of strength and corrosion resistance such as fasteners.

类型410

Contains lower carbon than Type 410, offers improved weldability but lower hardenability. Type 410S is a general purpose corrosion and heat resisting chromium steel recommended for corrosion resisting applications.

Type 414

添加了镍（2％）以改善耐腐蚀性。典型的应用包括弹簧和餐具。

铁素体不锈钢
These are alloys of iron, carbon, steel. These steels are based on Chromium with small amounts of Carbon usually less than 0.10%. These steels have a similar microstructure to carbon and low alloy steels. They cannot be hardened by heat treatment.Ferritic steels are also chosen for their resistance to stress corrosion cracking. They are not as formable as austenitic stainless steels. They are magnetic.

类型430

The basic ferritic grade, with a little less corrosion resistance than Type 304. This type combines high resistance to such corrosives as nitric acid, sulfur gases, and many organic and food acids.

Type 405

具有较低的铬并添加铝，以防止高温冷却时变硬。典型的应用包括热交换器。

Type 409

Contains the lowest chromium content of all stainless steels and is also the least expensive. Originally designed for muffler stock and also used for exterior parts in non-critical corrosive environments.

Duplex

Primarily used in chemical plants and piping applications, the duplex stainless steels are developing rapidly today and have a microstructure of approximately equal amounts of ferrite and austenite. Duplex stainless steels typically contain approximately 22-25% chromium and 5% nickel with molybdenum and nitrogen. Although duplex and some austenitics do have similar alloying elements, duplexes have higher yield strength and greater stress corrosion cracking resistance to chloride than austenitic stainless steels.

Precipitation Hardening

降水不锈钢是铬 - 尼克尔不锈钢，其中包含合金添加的添加物，例如铝，铜或钛，可通过溶液和衰老的热处理加固它们。它们可以在老年人的状态下是奥氏体或马氏体。降水 - 坚硬的不锈钢分为三种类型：马氏体，半衰老和奥氏体。与奥氏体（例如660型，也称为A286）相比，马氏体（例如630型）和半衰老（例如631型）可以提供更高的强度。

Applications and uses

化学工业 - 液体和固体的大型储罐和容器
食品行业 - 食品加工设备，例如挤奶机，储罐，拖运罐，管道，阀门，牛奶卡车等。还用于啤酒厂，酿酒和果汁行业。
Domestic uses – 304 stainless steel can resist the corrosive action of acids found in fruits, milk, meat and vegetables, and is fairly resistant to abrasion. Therefore, it is widely used in sinks, tabletops, stoves, refrigerators, cutlery, utensils and various other appliances.
建筑用途 - 镶板，成型，栏杆，装饰。
工业应用 - 工具，螺栓，螺母，螺丝等。
汽车和航空航天行业 - 燃油箱，各种结构组件。
医院 - 手术设备。
商业 - 卫生配件，管道。