subject: 2.4 Steel And Its Change [print this page] 2.4 Steel and its Change 2.4 Steel and its Change
Why the difference between the performance of steel, and steel in fact the internal organizational structure. Can be seen through the microscope, the internal steel is composed of many different departments and regions, such as cell stack the same product made of small, carefully view
Police, in fact belong to these small lumps of several different categories, we are usually the same kind of small horizontal called a "phase" or a "body." As we usually say austenitic, ferritic steel refers to the most
Two common organizational structure, which is two phase. Which contains a kind of steel phase, the proportion of each phase the number, shape how the phase, which directly affect the performance of steel. That is, if the steel
In the phase of the type, proportion, shape change, we must follow the performance of steel changes. Then, what factors will lead to changes in these years then? Clearly, changes in the composition of steel will definitely affect the performance of steel
Change, and for a certain kind of steel components for a fixed, such as 20 # steel, or 304L, as they are for deformation processing, heat treatment, its performance will change. To sum up, affecting steel
Performance of the main factors are: composition, deformation and temperature.
2.5 Steel Heat Treatment:
In order to achieve some kind of steel we want the best performance, its internal organizational structure and stability to a stable structure of a particular state.
In many cases, we must be heat-treated steel. Because many of our products are made of processed deformed, the deformation of steel by the above-mentioned, its structure must change
In other words, the performance of the steel changes, which often we do not want change, and then we must take measures to eliminate heat treatment of these changes and restore the original properties of steel. Of course
, Because of other considerations we have carried out other means of heat treatment. Several steel by cold, heat treatment after hot deformation see Table 1.
2.6 steel, said method:
Representation of the world steel varies, but most expressed by two methods: one to contain the alloy elements and content to that kind of code for a class of steel and strength values to represent. For example:
20 # - that 0.20% of the carbon content of the advantages of carbon steel
45 # - that is about 0.45% carbon content of the advantages of carbon steel
1Cr18Ni9Ti-that the carbon content: 0.1%
Cr18% or so
Ni 9% around
Ti: with a little
0Cr18Ni9-that very low carbon content, 0.08%
Cr 18% around
Ni 9% around
Q235 ----- that yield strength> 235MPA of carbon steel
SS400 --- that the tensile strength> 400MPA the advantages of carbon steel
