The performance of stainless steel and organization

There are more than 100 known chemical element, in that is commonly used in industrial steel material can meet about twenty kinds of chemical elements. For people in a long struggle with the corrosion phenomenon formed by the practice of the special steel stainless steel series, the most commonly used element has a dozen, in addition to the basic elements in iron steel, with the largest elements affect on the performance of the stainless steel is: carbon, chromium, nickel, manganese, silicon and molybdenum, titanium, niobium, titanium, manganese, nitrogen, copper, cobalt, etc. These elements other than carbon, silicon, nitrogen, are chemical elements in the periodic table is located in the transition of the element. Stainless steel in industrial application are actually exist several or even dozens of elements at the same time, when several elements coexist in stainless steel which a unity, their impact is much more complicated than single exists, because in this case not only to consider the elements themselves, and pay attention to the mutual influence between them, so the organization of the stainless steel is determined by the influence of various elements combined. 1) The influence of various elements on the performance of the stainless steel and organization and function of 1 - 1. Chromium in stainless steel works: decisions of stainless steel is there is only one element, and this is chrome, each stainless steel containing a certain amount of chromium. To date, there has been no do not contain chromium stainless steel. Chromium is decided the main elements of the stainless steel performance, the fundamental reason is that after adding chromium alloy elements into the steel, make its internal contradiction movement to the aspects of development in the resistance to corrosion damage. This change can be illustrated from the following aspects: (1) chromium chromium increase the electrode potential of iron base solid solution (2) electronic absorption of iron iron passivation passivation is caused by metal and alloy anode reaction is prevented and the phenomenon of corrosion resistance was improved. Many composition of metal and alloy passivation theory, mainly include thin film theory, adsorption on the electronic structure theory. 1 - 2. Carbon in duality of stainless steel carbon steel is used in industry, one of the main elements of the performance of the steel and organization to a large extent depends on the content and distribution of carbon in steel form, the influence of the carbon in the stainless steel is particularly significant. Carbon impact to the organization in the stainless steel is mainly manifested in two aspects, on the one hand, carbon austenitic elements are stable, and the role of a large ( About 30 times of nickel) , on the other hand, due to the affinity of carbon and chromium is very big, and chromium form - Series of complex carbide. So, from both a strength and corrosion performance of candle, the role of carbon in stainless steel is contradictory. Understanding the influence of the rule, we can from the use of different requirements, choose different carbon content of stainless steel. The most widely used in industry, for example, is at the very least stainless steel - — Crl3 0 ~ 4 cr13 these five steel grade standard chrome gauge for 12 ~ 14%, is to put the carbon and chromium after the formation of chromium carbide factors into consideration, the purpose is to make the carbon and chromium as chromium carbide, the chromium content of solid solution is not less than 11. A minimum 7% chromium content. In terms of the five steel grade because the carbon content, strength and corrosion resistance are also differentiated, cr13 0 ~ 2 crl3 steel has good corrosion resistance but strength is lower than 3 crl3 and 4 cr13 steel, more used in the manufacture of structural parts, after two steel grade can be obtained due to the high carbon