At present, most of the machine tool castings are gray cast iron. The quality of large gray cast iron castings should be controlled strictly from the aspects of chemical composition, raw material quality, ingredients, alloying, melting temperature, incubation treatment and thermal aging.
At present, most of the machine tool castings are gray cast iron. The quality of large gray cast iron castings should be controlled strictly from the aspects of chemical composition, raw material quality, ingredients, alloying, melting temperature, incubation treatment and thermal aging.
1, melting links
1) Carbon equivalent. Higher carbon equivalent should be used, HT250, 3.95 is better; HT300, 3.82 is better; HT350, 3.76 is better.
2) Silicon-carbon ratio. Proposed best silicon-carbon ratio control in the 0.55-0.62.
3) alloying control. Addition of alloying elements is beneficial to the improvement of casting performance, generally 0.4-0.6% of w (Cu) or 0.2-0.4% of w (Cr).
2, ingredients
Pig iron to join the amount of less than 10%, while using high-scrap, high-carburizing process, so good quality graphite.
3, hot metal temperature
High iron liquid temperature can be refined graphite, is a high carbon equivalent, high strength gray cast iron foundation. Iron liquid temperature is 1500-1550 ℃, the oxidation of molten iron will be reduced, SiO2 ash significantly reduced.
4, pregnant
Stainless Steel Handle Lock,Door Hardware and Locks,Stainless Steel Door Handles,Polished Stainless Steel Lever Door Handle
NINGBO DAIKE INTELLIGENT TECHNOLOGY CO.,LTD , https://www.daker-hardware.com