The factors of stainless steel efffected
Currently known chemical elements are more than 100 kinds of chemical elements in the steel industry commonly used materials can be encountered about two dozen. For people in practice and corrosion phenomena and the formation of the long struggle of the special stainless steel series, the most common element in a dozen, in addition to the basic elements of the composition of the steel iron, stainless steel performance and organization of the most influential elements are: carbon, chromium, nickel, manganese, silicon, molybdenum, titanium, niobium, titanium, manganese, nitrogen, copper, cobalt and the like. These elements other than carbon, silicon, nitrogen, are located in the periodic table transition group elements.
Actually applied on an industrial stainless steel are much more complex when several simultaneous presence of several elements to ten, when several elements co-exist in a continuum in which stainless steel, their impact than alone, because in this not only to consider the case of the elements of their own role, and they should pay attention to the impact between each other, so the organization decided sum of stainless steel in various elements affected.
1, the decisive role of chromium in stainless steel
Determine the elements of stainless steel of only one genus, which is chrome, stainless steel each contain a certain amount of chromium. To date, no chromium-free stainless steel. Chromium stainless steel performance have become key elements decided, the fundamental reason is added to the steel as an alloying element chromium later, prompting its internal conflicts in favor of the resistance movement to respect the development of corrosion damage. This change can be explained from the following aspects:
① the electrode potential of the iron-chromium-based solid solution to improve
② electronic chromium iron absorption iron passivation
Passivation is blocked due to the anode reaction caused by the corrosion resistance of metals and alloys can be improved phenomenon. Theory of metals and alloys constitute passive lot, mainly film theory, adsorption on addressing electronic arrangement.
2, carbon duality in stainless steel
Carbon is one of the main elements of industrial steel, steel performance and organization largely depends on the form of carbon in the steel content and distribution, the impact of the carbon in stainless steel is particularly significant. Effect of carbon in the stainless steel of the organization mainly in two aspects, one is the element carbon stable austenite, and the extent of the role of large (approximately 30 times the nickel), partly because the affinity of carbon and chromium are large, and chromium form - series of complex carbides. So, from the strength and corrosion candle performance both in terms of the role of carbon in stainless steel are mutually contradictory.
