I believe that people who understand die-casting die steel know that hardness is one of the main technical goals of die-casting die steel. It mainly refers to the ability of metal materials to resist other harder objects being pressed into their surfaces, not only to measure the hardness of metal materials. , but also a way to reflect the function of steel. There is also a certain relationship between its hardness and the process properties of the material such as cold formability, machinability, weldability, etc., so it can be used as a reference when formulating processing technology. So do you know how to test the hardness of die casting mold steel?
In the die-casting mold steel, there are mainly the following three kinds of hardness testing methods:
1. Brinell hardness test method:
The Brinell hardness can first be pressed into the surface of the model with a regular test force (F) through a steel ball or carbide ball of a certain diameter, and then the test force can be removed after a regular holding time to measure the indentation on the surface of the sample. Diameter (L). The Brinell hardness value obtained after Z is the quotient obtained by dividing the experimental force by the outer surface area of the indentation sphere. The use of Brinell hardness measurement is generally more accurate and reliable, and it is also more intuitive and convenient.
2. Rockwell hardness test method:
The Rockwell hardness test method is the same as the Brinell hardness test method, and both belong to the indentation test method. However, Rockwell hardness refers to measuring the depth of the indentation, that is, under the effect of the initial test force (Fo) and the total test force (F), the indenter (cone or steel ball) is pressed into the sample On the surface, after the regular holding time, the main test force is removed, and the hardness value is calculated by the measured residual indentation depth increment (e). And this test method can also directly read the hardness value from the dial of the hardness machine. However, because of its small indentation, the hardness value is not as accurate as the Brinell method.
3. Vickers hardness test method:
The Vickers hardness test method is also one of the indentation test methods. It is to press a regular quadrangular pyramid diamond indenter with a relative angle of 1360 into the experimental surface with a selected experimental force (F). After time, the experimental force was removed, and the lengths of the two diagonals of the indentation were measured. Therefore, its Vickers hardness value is the quotient obtained by dividing the experimental force by the outer area of the indentation. However, because it has the main advantages of Brinell and Rockwell methods, it can be used to determine the hardness of very thin metal materials and surface layers.
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