Mold is the basis of the mechanical industrial production technology and equipment, is an indispensable tool in production of industrial products, the performance of the steel production mold need to through the strict supervision of production technology, raw materials of production tooling also will have to pass strict control, prevent premature failure of the mold because of material problem form the cracking defects such as heat treatment.
The control of the raw material of the mold is carried out in the following aspects:
1. Macroscopic examination
Chemical composition is decisive to guarantee the performance of the steel, but the composition is qualified, not to show that the steel performance comprehensively, because of the steel internal organization and composition of the inhomogeneity, macroscopic examination to a large extent added to the deficiency of.
Macroscopic test can observe the crystallization of steel, the continuous damage of steel and the inhomogeneity of certain components.
Standard "low-power structure of structural steel" GB1979.
Macroscopic common 8 kinds of defects: segregation, loose, inclusions, shrinkage cavity, bubble, white point, crack, folding.
2.1 evaluation of annealing organization.
The purpose of annealing is to reduce the hardness of the steel and facilitate machining, while also preparing for the subsequent heat treatment.
Carbon tool steel annealing organization is rated according to the first level rating of GB1298.