刚的热处理（Heat treatment）.docVIP

刚的热处理（Heat treatment） Heat treatment of metal materials is an important method to improve and improve the performance of parts. Therefore, heat treatment is indispensable in the manufacture of parts. A common metal material - steel and cast iron Metallic materials include pure metals and their alloys (that is, metal materials formed by adding other elements to a metal). Metal materials are divided into two categories in industry: one is black gold Genera, it includes iron, manganese, chromium and its alloys, which are the most widely used in ferrous alloys (i.e., steel and cast iron). Another class of non-ferrous metals refers to all metals other than black metal The alloy. Of metal used in industry, steel and cast iron are used most. Steel and cast iron (collectively called iron and steel) are made of iron and other alloy elements such as carbon Its called iron carbon alloy material. Iron carbon alloys, which typically contain less than 2% of carbon, are called steel. More than 2% of the iron carbon alloy is called cast iron. 1. Classification, numbering and performance characteristics of steel: According to the composition different steel can be divided into carbon steel (carbon steel) and alloy steel. (1) carbon steel Iron and carbon are the main elements of carbon steel, but they often contain impurities such as Mn, Si, S, P, etc., and the performance of S and P is very bad for steel. Therefore, according to the content of sulfur and phosphorus, steel It is divided into: general quality steel (S is not equal to 00.0 %, P is less than 0.005%) quality steel (S is less than 0.03%, P is less than 0.035%), high quality steel (S is less than 0.02%, P is less than 0.003%), etc. The performance of carbon steel The carbon intensity of carbon steel, the strength of carbon steel, the strength of the hardness, the plastic and the toughness decrease as the carbon quantity increases. According to the amount of carbon, carbon steel is classified as low carbon steel Carbon stee