rdinary carbon steel is also known as iron carbon alloy. According to the high and low carbon content, the stainless steel drill tail screw is divided into low carbon steel, medium carbon steel and cast iron. Low carbon steel, commonly known as mild steel or pure iron, is less than 0.2%. The content of steel is 0.2-1.7%. The content above 1.7% is called pig iron.
In steel, the chromium content is more than 12.5%, which has a high resistance to the external medium (acid, alkali salt) corrosion steel, called stainless steel. According to the organization of the situation in the steel, stainless steel can be divided into martensite shape, iron grain size, austenite and ferrite, austenite size, precipitation hardening stainless steel, according to the national standards GB3280-92, a total of 55.
We contact more in our daily life has austenite stainless steel (some call it nickel stainless) and martensite stainless steel (some call it "stainless iron", but not science, easily misunderstood, should be avoided) two kinds big. The typical brand of austenitic stainless steel is 0Cr18Ni9, i.e. "304" and 1Cr18Ni9Ti. Markov type stainless steel, such as stainless steel with knife cut, is mainly used in 2Cr13, 3Cr13, 6Cr13, 7Cr17, etc.
Because of the difference in the composition of these two kinds of stainless steel, the inner metal microstructure is different.
Austenite stainless steel size because of the high chromium and nickel in steels (chromium at about 18%, Ni in more than 4%), steel internal organization of a state called austenitic organization, this organization has no magnetic conductivity, not attracted by magnet. Used as decorative materials, such as stainless steel tubes, towel racks, tableware, stoves and so on.
The stainless steel of the cutter shears is made of martensitic stainless steel. Because the knife shear has the function of the cut item, must have the sharpness, must have the sharpness must have certain hardness. This type of stainless steel must undergo heat treatment to change its internal structure and increase the hardness before it can be cut. But this kind of stainless steel inner structure is tempered martensite, which has the magnetic conductivity, can be attracted by the magnet. Therefore, it is not easy to use magnetism to indicate whether it is stainless steel. The main research