被用于电梯门套的不锈钢主要有201不锈钢与304不锈钢以及复合不锈钢三种。

There are mainly three types of stainless steel used for elevator door frames: 201 stainless steel, 304 stainless steel, and composite stainless steel.

主要区别：

Main differences:

成分：由于其成本不同，不同。

Ingredients: Due to their different costs and prices.

质量好一些，同时相对较贵；

The quality is better, while the price is relatively expensive;

相对差一些，但有一定优势；

Relatively inferior, but with a certain price advantage;

复合不锈钢介于两者之间。

Composite stainless steel falls between the two.

组成：201组成为17Cr-4.5Ni-6Mn-N，是节Ni钢种，301钢的替代钢。经冷加工后具有磁性，用于铁路车辆。

Composition: 201 is composed of 17Cr-4.5Ni-6Mn-N, which is a Ni steel grade and a substitute for 301 steel. After cold processing, it has magnetism and is used in railway vehicles.

304组成为18Cr-9Ni，是得到广泛应用的不锈钢、耐热钢。用于食品生产设备、昔通化工设备、核能等。

304 is composed of 18Cr-9Ni and is the most widely used stainless steel and heat-resistant steel. Used in food production equipment, Xitong chemical equipment, nuclear energy, etc.

复合不锈钢为304不锈钢薄板和镀锌板加热到200℃，通过中间介质高分子膜贴合而成，产品结构紧密，具有减震、降噪、强度高等优点，由于厚度较厚，用于电梯轿厢、厅门、轿门等。

Composite stainless steel is made by heating 304 stainless steel sheet and galvanized sheet to 200 ℃, and bonding them with a polymer film as an intermediate medium. The product has a compact structure, which has the advantages of shock absorption, noise reduction, and high strength. Due to its thick thickness, it is used in elevator cars, hall doors, car doors, etc.

201是含锰较高,表面很亮带有暗黑的亮,含锰较高容易生锈。

201 has a high manganese content and a bright surface with a dark luster. It is prone to rusting due to its high manganese content.

含铬较多,表面呈现哑光,不生锈.两种放在一起就有比较了。

Contains more chromium, appears matte on the surface, and does not rust. The two are compared when placed together.

重要的就是耐腐蚀性能不同,201的耐腐蚀性能很差,所以就要便宜很多.又因为201含镍低，所以比304的低，于是耐腐蚀性能就不如304的了。

The most important thing is that the corrosion resistance is different. The corrosion resistance of 201 is very poor, so the price is much cheaper. Also, because 201 contains low nickel, the price is lower than 304, so the corrosion resistance is not as good as 304.

复合不锈钢表面由304组成，表面具有304不锈钢的特性。

The surface of composite stainless steel is composed of 304 and has the characteristics of 304 stainless steel.

201不锈钢在特定环境下会生锈，譬如说放置于盐水浸泡就会生锈，但是日常环境下是极不易生锈的。不锈钢材质是因为含有镍元素，才有不易生锈的能力，而相较于304不锈钢来说，201不锈钢中的镍元素会更少，因此要比304不锈钢更容易生锈。复合不锈钢的表面材质为304不锈钢，而生锈主要表层氧化，因此复合不锈钢抗锈蚀能力优于201不锈钢。

201 stainless steel will rust in specific environments, such as when immersed in salt water, but it is extremely difficult to rust in daily environments. Stainless steel materials have the ability to rust less easily due to the presence of nickel, and compared to 304 stainless steel, 201 stainless steel has less nickel, making it easier to rust than 304 stainless steel. The surface material of composite stainless steel is 304 stainless steel, and rust is mainly caused by surface oxidation, so the corrosion resistance of composite stainless steel is better than that of 201 stainless steel.

不锈钢具有抵抗大气氧化的能力——即不锈性，同时也具有在含酸、碱、盐的介质中乃腐蚀的能力——即耐蚀性。但其抗腐蚀能力的大小是 随其钢质本身化学组成、加护状态、使用条件及环境介质类型而改变的。如304钢管，在干燥清洁的大气中，有优良的抗锈蚀能力，但将它移到海滨地区，在含有大量盐份的海雾中，很快就会生锈了；而316钢管则表现良好。因此，不是任何一种不锈钢，在任何环境下都能耐腐蚀、不生锈的。

Stainless steel has the ability to resist atmospheric oxidation - i.e. rust resistance - and also has the ability to corrode in media containing acids, alkalis, and salts - i.e. corrosion resistance. But the magnitude of its corrosion resistance varies with the chemical composition of the steel itself, the protective state, usage conditions, and the type of environmental medium. For example, 304 steel pipes have absolutely excellent rust resistance in a dry and clean atmosphere, but when moved to coastal areas, they will quickly rust in sea mist containing a large amount of salt; And 316 steel pipe performs well. Therefore, not any type of stainless steel can withstand corrosion and rust in any environment.

当不锈钢管表面出现褐色锈斑（点）的时候，人们大感惊奇：认为 “不锈钢是不生锈的，生锈就不是不锈钢了，可能是钢质出现了问题”。其实，这是对不锈钢缺乏了解的一种片面的错误看法。不锈钢在一定的条件下也会生锈的。

When brown rust spots (spots) appear on the surface of stainless steel pipes, people are greatly surprised: they believe that "stainless steel does not rust, and if it rusts, it is not stainless steel, it may be a problem with the steel quality.". In fact, this is a one-sided erroneous view that lacks understanding of stainless steel. Stainless steel can also rust under certain conditions.