Because different aims of precision casting, heat treatment, basic can be mainly divided into two categories, the first category is the organization structure will not change or by heat treatment and should not be changed, the second is the basic organizational structure change.The first heat treatment procedure is mainly used to eliminate internal stress, which is caused by different cooling conditions and conditions during the casting process of stainless steel.The structure, strength and other mechanical properties are not significantly changed due to heat treatment.
For the second type of heat treatment, there are significant changes in al qaeda, which can be divided into five categories:
1. Softening annealing: its purpose is to decompress the carbide, reduce its hardness, and improve the processing performance. For ductile iron, the purpose is to obtain more ferritic tissues.
2. Positive fire treatment: the main purpose is to obtain the mechanical properties of the pearlite and soxite tissues to improve the casting of stainless steel.
3. Quenching treatment: mainly to obtain higher hardness or abrasion strength, and to very high surface abrasion resistance.
4. Surface hardening treatment: mainly to obtain the surface hardening layer, and get very high surface abrasion resistance.
5. Precipitation hardening treatment: it is mainly to achieve high strength and the elongation rate does not cause drastic changes.