被用于電梯門套的不銹鋼主要有201不銹鋼與304不銹鋼以及復合不銹鋼三種。

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

主要區別：

Main differences:

成分：由于其成本不同，價格不同。

Ingredients: Due to their different costs and prices.

質量好一些，同時價格相對較貴；

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

相對差一些，但價格有一定優勢；

Relatively inferior, but with a certain price advantage;

復合不銹鋼介于兩者之間。

Composite stainless steel falls between the two.

組成：201組成為17Cr-4.5Ni-6Mn-N，是節Ni鋼種，301鋼的替代鋼。經冷加工后具有磁性，用于鐵路車輛。

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組成為18Cr-9Ni，是得到最廣泛應用的不銹鋼、耐熱鋼。用于食品生產設備、昔通化工設備、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.

復合不銹鋼為304不銹鋼薄板和鍍鋅板加熱到200℃，通過中間介質高分子膜貼合而成，產品結構緊密，具有減震、降噪、強度高等優點，由于厚度較厚，用于電梯轎廂、廳門、轎門等。

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是含錳較高,表面很亮帶有暗黑的亮,含錳較高容易生銹。

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.

含鉻較多,表面呈現啞光,不生銹.兩種放在一起就有比較了。

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

最重要的就是耐腐蝕性能不同,201的耐腐蝕性能很差,所以價格就要便宜很多.又因為201含鎳低，所以價格比304的低，于是耐腐蝕性能就不如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.

復合不銹鋼表面由304組成，表面具有304不銹鋼的特性。

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

201不銹鋼在特定環境下會生銹，譬如說放置于鹽水浸泡就會生銹，但是日常環境下是極不易生銹的。不銹鋼材質是因為含有鎳元素，才有不易生銹的能力，而相較于304不銹鋼來說，201不銹鋼中的鎳元素會更少，因此要比304不銹鋼更容易生銹。復合不銹鋼的表面材質為304不銹鋼，而生銹主要表層氧化，因此復合不銹鋼抗銹蝕能力優于201不銹鋼。

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.

不銹鋼具有抵抗大氣氧化的能力——即不銹性，同時也具有在含酸、堿、鹽的介質中乃腐蝕的能力——即耐蝕性。但其抗腐蝕能力的大小是 隨其鋼質本身化學組成、加護狀態、使用條件及環境介質類型而改變的。如304鋼管，在干燥清潔的大氣中，有絕對優良的抗銹蝕能力，但將它移到海濱地區，在含有大量鹽份的海霧中，很快就會生銹了；而316鋼管則表現良好。因此，不是任何一種不銹鋼，在任何環境下都能耐腐蝕、不生銹的。

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.

當不銹鋼管表面出現褐色銹斑（點）的時候，人們大感驚奇：認為 “不銹鋼是不生銹的，生銹就不是不銹鋼了，可能是鋼質出現了問題”。其實，這是對不銹鋼缺乏了解的一種片面的錯誤看法。不銹鋼在一定的條件下也會生銹的。

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.