中文版Is assorted is the stainless steel?
The stainless steel is increases certain content in the carbon steel foundation chromium element smelting to make. Why doesn't it rust anti-corrosive? The primary cause lies in the steel to include the chromium. As a result of the chromium influence, under corrosive medium's function, a steel stock surface production firm compact oxide compound membrane, is called as “the deactivated membrane”. This membrane is extremely thin and transparent, the naked eye does not look nearly, saw is still the silvery bright gloss metal surface. This membrane causes the metal and the outside medium isolation, the impediment metal is further corroded; And also has the self-repair ability, once if is destructed, in the steel chromium can produce the deactivated membrane with the medium in oxygen, continues the protective function.
The carbon steel and this is dissimilar. Under corrosive medium's function, the carbon steel surface will produce the loose oxidized nill very quickly, will be the rust which often said that it cannot prevent the metal and the medium isolates, the outside oxygen atom will proliferate unceasingly toward in causes the steel stock to continue to rust, the corrosion, so that will destroy completely.
The stainless steel can not rust, anti-corrosive, needs how many are the lowest chromium content? American, in the European standard stipulated that for is not smaller than 10.5% (quality score, latter with), Japan industrial standard stipulated that generally is not smaller than approximately 11%, our country thought generally is not smaller than 12%. In fact, the stainless steel anti-corrosive performance, to the chromium element's content request, is decided by the corrosive medium type, the density, the temperature, the pressure, the flow rate, as well as in steel besides chromium other alloying element and so on many factors.
In order to enable the stainless steel both to have the good anti-corrosive performance, and has the good mechanics and physics and so on other performance, according to various requirement, in steel besides increase high content alloying element chromium, but also matches the increase nickel, the molybdenum, the manganese, the nitrogen and so on other alloying element. Thus, not only may change the deactivated membrane the chemical composition, strengthens it in harsh medium anti-corrosive ability, moreover enables the steel products also to obtain the enough intensity, the plasticity and toughness, as well as the good shop characteristics, like may the weldability, the processing formable and so on.
