In addition to the fixed carbon content and ash content of the carburizer has an important effect on its carburizing efficiency in cast iron, the particle size of the carburizer, the way of adding, the temperature of liquid iron and the stirring effect in the furnace and other process factors have a significant effect on the efficiency of carburizing.
In production conditions, many factors often play a role at the same time, it is difficult to make an accurate description of the impact of each factor, the need to optimize the process through experiments.
1. Add method
Carburizing agent in charging with metal charge together into the furnace, due to the long time of action, carburizing efficiency is much higher than the iron when adding liquid iron.
2. Temperature of liquid iron
When the iron recarburizer will be added to the bag, and then into the liquid iron, carbon efficiency and the temperature of the liquid iron. Under normal production conditions, when the temperature of liquid iron is higher, carbon is more soluble in liquid iron and the efficiency of carburization is higher.
3 carburizer particle size
In general, carburant particles is small, its contact with the iron liquid interface area is large, increase the efficiency of carbon will be higher, but the too fine particles of easy oxidation by oxygen from the atmosphere, also easy to be caused by convection of air or smoke dust flow away, therefore, carburant particle size of the lower limit value with 1.5 mm advisable, and should not contain among them fine powder under 0.15 mm.
The particle size should be measured in terms of the amount of molten iron that can be dissolved during operation time. If the carburizer is added together with the metal charge when loading, the action time of carbon and metal is long, the particle size of the carburizer can be larger, and the upper limit can be 12mm. If the iron is added to the liquid iron, the particle size should be smaller, the upper limit is generally 6.5mm.
4. Stir
Stirring is beneficial to improve the contact between carburizer and liquid iron and improve its carburization efficiency. In the case of carburizing agent and charge together into the furnace, there is an induced current stirring effect, carburizing effect is better. Add carburizing agent to the bag, carburizing agent can be placed at the bottom of the bag, iron when the liquid iron directly blunt carburizing agent, or continuous carburizing agent into the liquid flow, not in the liquid surface of the bag after the iron.
5 avoid carburizing agent involved in slag
Carburizing agent if involved in slag, can not contact with liquid iron, of course, will seriously affect the effect of carburizing.
Post time: Oct-22-2021