Weathering steel, also known as atmospheric corrosion-resistant steel, is a low-alloy steel between ordinary steel and stainless steel. It is made of ordinary carbon steel with a certain amount of copper added, and corrosion-resistant elements such as phosphorus, chromium, nickel, titanium, and vanadium. It not only has the characteristics of easy ductility, high strength and fatigue resistance of ordinary steel, but also can reach 2-8 times of ordinary carbon steel in terms of corrosion resistance. Due to its excellent properties, weathering steel is expensive. Compared with ordinary steel, the price of weathering steel with similar properties is about 60% higher. Therefore, don't look at the ugly weathering steel, the general building can't use it. Weathering steel is only used for structures such as containers, railway vehicles, oil derricks, and drilling platforms that are used in harsh environments and require high corrosion resistance of steel. As for the reinforced concrete used in ordinary buildings, because the steel bars buried in the concrete rarely come into contact with oxygen and water, engineers are reluctant to use weathering steel here!
(Typical weathering steel application: offshore drilling platform)
Pure iron is not easy to rust, but ordinary steel usually contains impurities such as copper and carbon. These impurities are less active than iron, and form a galvanic battery with iron in water-containing air (that is, a current that generates current through redox reactions. A device) that separates the oxidation and reduction reactions and provides a "highway" for the corrosion of steel. The rust produced by the corrosion of steel is a loose and porous structure with many micro-cracks connecting the pores to each other. In this way, the rust acts like a sponge and can continue to absorb moisture from the air, allowing the steel to rust further until it is completely rusted through.
Weathering steel is different from ordinary steel. In the beginning, it will rust on the surface like ordinary steel. This process is even faster than normal steel due to its higher degree of alloying. However, due to the more complex lattice inside the weathering steel, a dark black dense rust layer will grow under the loose rust on the surface. This rust layer consists of nanoparticles of α-FeOOH. In this dense rust layer, nickel atoms replace some of the positions of iron atoms, which makes the rust layer have cation selectivity and inhibits the permeation of corrosive anions.
(The left is weathering steel, the right is rust, you can clearly see the difference between the two)
It is this dense rust layer that makes the weathering steel rust on the surface, but the interior will not continue to be rusted. In fact, as long as you distinguish carefully, you can see that the surface of weathering steel is not the same as ordinary rust: the rust of weathering steel is uniform and dense, and it is close to the surface of the steel to protect the steel; while the rust is mottled, loose and porous, It will fall off when touched. Instead of protecting the steel, such rust "brings wolves into the room" and draws water and oxygen to the surface of the steel.
In fact, weathering steel is not a material that has only recently emerged.
As early as 1900, Americans had already started the early research and development of copper-containing steel, which is the predecessor of weathering steel. However, in the first half of the 20th century, the level of human science and technology was limited, and it was difficult to conduct in-depth research on the microscopic materials of materials. The mechanism behind the corrosion resistance of weathering steel was not clear, which greatly limited the research and application of weathering steel. In addition, the total construction volume of humans at that time was far from what it is today, so the research progress of weathering steel has been relatively slow.
In China, it was not until 1960 that the research on copper-containing weathering steel started at WISCO.
But today, due to the rapid development of China's economy, the amount of engineering construction around the world has grown exponentially. Offshore oil platforms and seaport buildings have become ubiquitous, and the world's demand for weathering steel is becoming more and more urgent. In addition, today's air pollution is becoming more and more serious, and metal structures will inevitably face the baptism of acid rain. Any metal will naturally begin to corrode as soon as it is put into use. With the increasing number of possessions, the corrosion of metals begins to cause heavy losses to the national economy. According to incomplete statistics, the annual economic losses caused by corrosion of steel structures account for 2%-4% of the gross national economic product. At present, the economic losses caused by structural corrosion each year are as high as trillions of dollars. This means that every year an entire UK of people loses a year of hard work due to metal rusting.
The development and promotion of weathering steel can improve the durability of the structure and greatly reduce the economic loss caused by corrosion. Therefore, the research on weathering steel in China caught up with the good time, started very fast, and caught up very quickly.
Since the 1990s, in order to adapt to China's explosive development of infrastructure, break foreign monopoly and strive for a broader overseas market, researchers have turned their attention to new high-performance weathering steel with low cost, high strength and higher corrosion resistance. developed and achieved excellent results. The weathering steel developed in China does not contain nickel and chromium, but mainly adds copper and phosphorus, and incorporates a certain amount of metal elements such as vanadium, titanium, niobium, rhenium, etc. which are rich in China, which greatly improves the quality and reduces the cost. More than half of it has gained a rolling advantage in the international market in one fell swoop.
Today, China is already a major producer and exporter of weathering steel. Especially in the field of bridge construction, China's weathering steel can not only meet the high strength, low yield ratio, low temperature toughness, weldability and thick plate uniformity required by steel for long-span bridges, but also has corrosion resistance. It can cope with all kinds of polluted environments with ease. You can choose to paint and stabilize the surface, or you can simply ignore it and use it directly. Weather-resistant steel is also matched with weather-resistant welding materials and weather-resistant high-strength bolts, and there are related standards and specifications behind them. The "weather-resistant family" established by the Chinese has greatly improved the human's ability to utilize steel, making high durability the norm for steel structure buildings.
(Weathering Steel Specifications, Weathering Steel Plates, and Weathering Bolts)
Cost-effectiveness is important, and beauty is also important
In the 21st century, people's requirements for architecture are getting higher and higher. In addition to being safe, durable, and affordable, it's also beautiful. In the post-industrial era, some artists returned to their simplicity and began to pursue the "true color" of architecture. Therefore, brown weathering steel is favored by architects for its full post-modern aesthetics.
On the Yanqi Lake campus of the University of Chinese Academy of Sciences, such a Zhongdan Center Building with all weathering steel appearance has just been built. This is an extremely modern building from appearance to function. Advanced technologies such as computers, wireless communication data transmission, spread spectrum power carrier communication technology, and computer intelligent information are used in many places to achieve high intelligence and low energy consumption of the building. Different from ordinary buildings, in order to achieve efficient use of natural light, the Zhongdan Center Building does not use conventional curtains to block sunlight, but sets up a multi-directional woven weathering steel sunshade screen outside the glass curtain wall, which makes the entire building have weathering steel. Unique postmodern look.
(UCAS Zhongdan Center Building)
The brown color of the building now is the color of the protective layer naturally formed after the weathering steel sunshade screen is corroded in the air for half a year. Its color is uniform and dense, which makes people feel that this is not rust, but the color of the building itself. In other parts of the building, from the pine wood rings suspended from the ceiling, to the primary color terrazzo floor, to the fair-faced concrete spiral staircase, all adhere to the principle of not carving, relying on the texture of the material itself to dress up. The building is integrated with the tone and style of the weathering steel inside and out.
(An interior view of the Zhongdan Center)
In the future, there will be more and more buildings with rich artistic elements like the Zhongdan Center of UCAS. And our Chinese manufacturing can't stay at the practical level of "good quality and low price" forever.
Shandong Kuai Ma Steel Co., Ltd. is located in Liaocheng City in the west of Shandong Province. Mainly produce and process stainless steel products, carbon steel series, color-coated steel and galvanized steel products, honing series and seamless steel pipe series,etc.
Our products have been exported to 30 countries and regions. Europe, USA, Canada, United Kingdom, United Arab Emirates,Russia, Australia, South America, Middle East, Africa, India, etc. and our company has rich experience in freight forwarding,We can export to any country that shipping company can reach.
Sincerely welcome customers from home and abroad to consult and negotiate business, and create a better tomorrow together.
English
Spanish
Russian
Portuguese
Steel Plate
steel pipe
Stainless steel
Section steel
carbon steel plate
Steel plate processing
steel coil
steel rod
Home
