乐从钢材市场热镀锌钢板汽车车身外壳钢板镀锌薄钢板

汽车车身外壳绝大部分是金属材料，主要用钢板。汽车的钢板车身防锈蚀年限为什么能达10年以上？

Most of the car body shell is metal material, mainly with steel plate. Why can the steel plate body of the car reach more than 10 years?

镀锌薄钢板广泛应用在汽车上，这是因为它有良好的抗腐蚀能力。早年人们在试验中发现，将铁和锌放人盐水中，二者无任何导线联结时，铁和锌都会生锈，铁生红锈，锌生“白锈”；若在二者间用导线联结起来，则铁不会生锈而锌生“白锈”，这样锌就保护了铁，这种现象叫牺牲阳极保护。工程师正是将这种现象运用到实际生产中，生产了镀锌钢板。经研究，在镀锌量350克／平方米（单面）时，镀锌钢板在屋外的寿命（生红锈），田园地带约为15-18年，工业地带约为3-5年，这比普通钢板长几倍甚至十几倍。

Galvanized sheet steel is widely used in cars because of its good corrosion resistance. In the early years, people found that when iron and zinc were put in salt water, there was no wire connection, iron and zinc would rust, iron red rust and zinc "white rust"; if the two wires, iron will not rust and zinc "white rust", so that zinc protects the iron, this phenomenon is called sacrifice anode protection. Engineers have applied this phenomenon to the actual production, producing galvanized steel plate. After research, when the galvanized amount is 350 grams / square meter (single side), the life of galvanized steel plate outside the house (red rust), the rural area is about 15-18 years, the industrial area is about 3-5 years, which is several times or even ten times longer than the ordinary steel plate.

从20世纪70年代开始轿车车身钢板采用镀锌薄钢板，装配时镀锌面置于汽车内侧，提高车身耐蚀性能，非镀锌面置于汽车外侧，喷涂油漆。随着汽车对耐腐蚀性能的要求不断提高，镀锌钢板不断增加镀锌层重量，还出现了双层镀锌钢板。但由于增加镀锌重量也会使电镀锌的电能消耗大幅增加，导致材料成本的上升，因此20世纪70年代末又出现一种采用热浸镀锌工艺生产的镀锌钢板，称为热镀锌钢板。这种镀锌钢板用连续热镀锌工艺：冷轧板（注*）→加热→冷却至镀锌温度→镀锌→冷却→矫直。为了满足汽车对镀锌钢板的各种要求，一些生产厂家在镀锌生产线上对镀锌钢板进行扩散退火等特殊处理，以使钢板表面形成一种“锌－铁”合金镀层，其特点是涂漆后的焊接性和耐腐蚀性比纯锌镀层板要好。以后还出现了诸如“锌－铝－硅”、“锌－铝－铼”等合金化热镀锌钢板，使得热镀锌钢板的耐腐蚀性成倍提高，与油漆间的结合性能长期稳定。目前轿车已经广泛使用镀锌钢板，采用的镀锌钢板厚度从0.5至3.0毫米，其中车身复盖件多用0.6至0.8毫米的镀锌钢板。

Since the 1970s, the steel plate of the car body is galvanized thin steel sheet. During the assembly, the galvanized surface is placed on the inside of the car to improve the corrosion resistance of the car body, and the non-galvanized surface is placed on the outside of the car to spray paint. With the continuous improvement of automobile requirements for corrosion resistance, galvanized steel plate keeps increasing the weight of galvanized layer, and double galvanized steel plate also appears. However, because the increase of galvanized weight will also greatly increase the energy consumption of electrogalvanized, resulting in the rise of material cost, so in the late 1970s, a galvanized steel plate produced by hot dip galvanized process, called hot dip galvanized steel plate. This galvanized steel plate with continuous hot galvanizing process: cold rolled plate (note *) heating cooling to galvanized temperature galvanized cooling straightening. In order to meet the various requirements of galvanized steel plate, some manufacturers treat the galvanized steel plate on the galvanized production line, so as to form a "zinc-iron" alloy coating on the surface of the steel plate, which is characterized by the weldability and corrosion resistance after painting than the pure zinc plating plate. Later, there are such as "zinc-aluminum-silicon", "zinc-aluminum-rhenium" and other hot-dip galvanized steel plates, which makes the corrosion resistance of hot-dip galvanized steel plate improved exponentially, and the combination performance with the paint is stable for a long time. At present, galvanized steel plate has been widely used in cars, the thickness of galvanized steel plate from 0.5 to 3.0 mm, in which the body cover parts of 0.6 to 0.8 of galvanized steel plate mm.

例如德国奥迪轿车的车身部件绝大部分采用镀锌钢板（部分用铝合金板），美国别克轿车采用的钢板80%以上是双面热镀锌钢板，上海帕萨特车身的外复盖件采用电镀锌工艺，内复盖件内部采用热镀锌工艺，可以使车身防锈蚀保质期可长达11年。

Such as German audi car body parts mostly use galvanized steel plate (part with aluminum alloy plate), buick car steel more than 80% is double hot galvanized steel plate, Shanghai passat body outside galvanplating process, inside cover inside hot galvanized process, can make the body rust shelf life can be up to 11 years.