The Development of Stainless Steel in the World
Stainless steel is the best among metal materials. It has many excellent properties, such as corrosion resistance, heat resistance, low-temperature resistance, good processing performance, etc. Stainless steel has a beautiful appearance, low life cycle cost, and can be 100% recycled Utilization, so has been widely used in various industrial and civil fields, and it is a very good structural and functional material.
Stainless steel has a history of more than 90 years since its inception at the beginning of the last century. The invention of stainless steel is a great achievement in the history of world metallurgy. It not only laid a material foundation for the establishment, development, and technological progress of modern industry but also expanded in the civilian field. The application has also significantly improved people’s quality of life.
Looking back to history, more than 1,000 years ago, the iron pillars in ancient Indian temples and the iron men in front of ancient Chinese temples, etc, they were exposed to the atmosphere for many years, wind, rain, and sun exposure to selenium, but they were very resistant to corrosion. This phenomenon Aroused the attention of many scholars and experts. From 1820 to 1822, the British scholar Faraday (M. Faraday) first studied the rust problem of low-alloy steel as a subject. It can be said that he is the founder of stainless steel research.
By the beginning of the 20th century, scholars in Europe, France, Britain, Germany, and other countries have successively studied the stainless steel and passivation theories: in 1906, Frenchman L.B.Guillet (L.B.Guillet), Frenchman Porter in 1909 Wan (A.M. Portevin), in 1909 the British Giesen (W. Giesen) published metallurgical reports on Fe-Cr and Fe-Cr-Ni alloys and discovered the corrosion resistance of these alloys. From 1908 to 1911, the Germans P. Monnartz and W. Borchers discovered the passivation phenomenon and proposed the passivation theory of high Cr alloys. The research during this period was for the development of industry Laid a theoretical foundation with stainless steel.
The three major types of stainless steel (martensite, ferrite, and austenite) were developed almost simultaneously by the United Kingdom, the United States, Germany, and other countries around 1912. From 1912 to 1913, the British H. Brearly developed martensitic stainless steel containing 12% to 13% of Cr (equivalent to the current AISl420); from 1911 to 1914, the American C. Dantssigen (C. Dantssigen) W.R. Whitsey developed ferritic stainless steel containing 14% to 16% Cr (equivalent to the current AISI430 early stage); from 1912 to 1914, E. Maurer and Strauss in Germany (B.strauss) developed austenitic stainless steel containing C<1%, Cr 15%-40%, and Ni<20% (equivalent to the tough type of AISl304); in 1929, Straw of Krupp, Germany Sis obtained the patent right for low-carbon 18-8 austenitic stainless steel.
At the same time, in order to improve the corrosion resistance of stainless steel, they added elements such as Mo and Cu. In order to solve the sensitized intergranular corrosion of 18-8 steel, they added stable elements such as Ti and Nb through experiments. In the 1940s and 1950s, Bo developed nickel-saving Cr-Mn-N (200 series) stainless steel, ultra-low carbon (C≤0.03%) austenitic stainless steel resistant to intergranular corrosion, and developed C in the 1960s. +N≤150ppm ultra-pure ferritic stainless steel, etc., further expands and improves the variety and performance of stainless steel.
In addition to the above three categories, the other two types of stainless steels are duplex stainless steels (that is, ferrite + austenite duplex in the solid solution structure of the steel, in which the second phase is ≥15%, but now it is required to Phase stainless steels are mostly two-phase ratios up to 50:50) and precipitation hardening stainless steels (that is, cold heat treatment to control the stability of austenite and the precipitation of phases on the matrix to increase the strength of the stainless steel) are in the 20th century It was successfully developed in the 30s to 40s. In 1927, Bain and Griffiths first discovered the duplex structure.
In 1935, the German Unieux laboratory discovered that the corrosion resistance of austenitic stainless steel containing ferrite would be significantly improved, thereby obtaining austenite + ferrite Patent for duplex stainless steel. The United States developed the first generation of duplex stainless steel AlSl329 (Cr25Ni5Mo2) in the 1940s, and successfully developed the second generation (metalization with nitrogen) and the third generation of duplex stainless steel (pitting resistance equivalent in the 1970s and 1980s). Super DSS with value ≥ 40).
Precipitation hardening stainless steel was first developed by R. Smith of the United States in 1946. At that time, he successfully developed a martensitic precipitation hardening stainless steel 17-4PH, and then it has high strength and can be cold-worked and formed. The precipitation hardening stainless steel 17-7PH and PH15-7Mo have also been successfully developed. So far, the five main sheets of steel in the stainless steel family: martensite, ferrite, austenite, duplex steel, and precipitation hardening stainless steel are basically complete.
The progress of the main production technology of stainless steel has promoted the rapid development of stainless steel, especially the use of out-of-furnace refining, continuous casting, and the use of multi-roll cold rolling mills have improved the quality of stainless steel, increased the yield rate, and reduced production costs. The first is the smelting technology of stainless steel. In 1910, crucible furnaces were used to smelt stainless steel in small batches.
Then the electric arc furnace invented by the French Heroult began large-scale industrial production. After entering 1940, American D. CHilty studied the Cr-C temperature balance and put forward the theory of high-temperature decarburization and chromium preservation, which laid the foundation for the successful development of electric arc furnace recovery oxygen blowing method to smelt stainless steel. Although stainless steel scrap can be used for production at this time, the cost is still high, and stainless steel is still high-priced steel.
After entering the 1960s, Witten in Germany and Union Carbide in the United States successfully developed innovative VOD and AOD refining methods, which made the use of cheap raw materials (high-carbon chromium Iron) smelting stainless steel becomes possible, and the purity of steel is greatly improved, and the production cost of stainless steel is significantly reduced. At present, the AOD and VOD methods have become the mainstream technology for refining stainless steel.
The AOD method accounts for 68.7% of the total stainless steel output, and the VOD method accounts for 26.3%. The second is continuous casting technology. As early as 1857, H. Bessemer obtained the patent of continuous casting technology, but the first stainless steel continuous casting machine appeared in the United States in 1949. Canadian Atlas Company (Atlas) built the world’s first stainless steel slab continuous caster.
In 1960, Japan’s Nippon Steel Co., Ltd. built the world’s first stainless steel wide slab continuous caster with a width of more than 1m. Since then, the continuous casting machine technology of stainless steel has developed vigorously, and the ratio of stainless steel continuous casting has exceeded 95%, which has become a key technology for reducing the cost of stainless steel and increasing the yield rate. The third is a multi-roll cold rolling mill. The German W. Rohn first studied a multi-roll mill with 10 to 18 support rolls (later became a Sondvik 20-high rolling mill, but the width was not enough), 1932 It was further developed by T. Sendzimir and successfully developed the current 20-high rolling mill with small diameter tussah rolls.
Because it can roll wide widths, it has become popular quickly. It currently accounts for 90% of the world’s stainless steel cold rolling mills. Of course, in addition to the three above-mentioned technologies, other technologies such as the development of the Steckel rolling mill, the development of continuous annealing and pickling lines, the development of bright annealing technology, and the application of various testing and automation technologies have promoted the increasing scale of stainless steel production. The level is getting higher and higher.
The development and progress of the above three technologies have improved the quality and reduced the cost of stainless steel, from a few thousand dollars per ton in the past to more than 1,000 dollars at the end of the 20th century. As of 2002, the world’s stainless steel smelting output was about 23 million tons (including the CIS, Eastern European countries, and China). In 2002, the world’s apparent consumption of stainless steel was about 20 million tons. In 1950, the world’s stainless steel production was less than 1 million tons, and in 1990 it was 12 million tons. It can be seen that the development of stainless steel is fast.
The development of stainless steel demand is closely related to people’s living standards. The international stainless steel development experience shows that the consumption growth of stainless steel is 1.5 to 2 times of GDP. Historically, the development of the military industry has driven stainless steel, but now it is the rapid growth of civilian use and the expansion of the application field that has promoted the rapid development of stainless steel demand. Nowadays, stainless steel can be seen everywhere in our lives, starting from the tableware for eating, to urban landscapes, buildings, etc. As most of the stainless steel daily necessities use plates, the overall demand is mainly plate.
The concentration of stainless steel production is getting higher and higher. From the current world export of stainless steel, it can be seen that stainless steel production is mainly concentrated in several countries and regions such as Belgium, Germany, Japan, Taiwan Province of China, and the countries with the most plate exports are mainly concentrated Among several large factories, the output of the world’s top 10 factories accounts for 80% of the world’s demand. (Reproduced)