In the realm of industrial processes, calcium treatment plays a pivotal role. This technique’s efficacy hinges on precise optimization wire feeding parameters, driving efficiency and quality in production.
Content
Calcium treatment actuality
In industrial realm, most of steel plants using calcium treatment process during steelmaking currently. At the same time, lots of domestic steel plants’ researchers also studied for nodules and analyzed calcium treatment modification effect. Nowadays, this process also still makes nozzle clogged, because of improper calcium addition quantity mainly.
In the current stage, calcium treatment process still faced many problems. Including, biggest problems are inclusions modified insufficiently and getting lower calcium recovery. In order to solve these problems, some relevant researchers using method that macro-control parameters of wire feeding technique to make calcium easily to be absorbed. And then, attains the goal that improve calcium recovery and calcium remains.
Previous research achievements of wire feeding parameters
In the globe, many researchers have studied for optimizing wire feeding parameters, such as wire feeding horizontal region, wire feeding speed and depth, argon blowing system, amount of wire feeding and so on. It can improve calcium recovery and consummate effect of calcium treatment in a certain degree by their study for above parameters. Then, we will introduce research achievements of some above parameters briefly.
Wire feeding horizontal region:
There is no clear conclusion for choosing wire feeding region currently. Researchers put forward two views for it commonly.
Some researchers think that reasonable wire feeding region where mass transfer coefficient should be the largest and calcium diffusion speed is the fastest. It means wire feeding region is same to argon blowing region.
While other researchers think region that can make calcium stay much time is reasonable wire feeding region. They put forward a different view. Although metal mixed speed is the fastest in argon blowing region, argon bubbles promote calcium vaporization easily during its come-up process, it makes calcium escape easily and decreases calcium recovery. However, if you feed cored wire in descending flow of liquid steel, melted calcium will be forced to descend in this region and prolongs staying time in liquid steel, it is helpful to improve calcium recovery. But it is noted that mass transfer coefficient in molten steel descending flow is far smaller than nearby argon blowing region.
At present, both of two regions are utilized in different steel plants. But more studies and discussions are needed to know which wire feeding method can get better calcium treatment effect.
Wire feeding speed and depth:
According to introduction in the last article”Adding calcium methods in steelmaking“, we can clearly know that calcium melting and boiling point is lower and worse solubility in molten iron. In order to improve calcium recovery and consummate effect, it is necessary to prolong calcium metal existing time in molten steel. You should feed cored wire into molten steel as deep as possible to avoid more calcium burning loss. However, there has to be a limit to everything. Wire feeding depth is also not too deep, otherwise, cored wire will touch the bottom of ladle before it melted completely, it leads to abrasion of furnace lining in the bottom of ladle and calcium corrodes furnace lining. Relevant researchers in steel plant consider that depth should be 0.6-0.75 times of molten bath depth or above the bottom of ladle 100-200 mm approximately can get the best Ca recovery.
Now have to say wire feeding speed. Appropriate wire feeding speed can feed cored wire into proper depth that above mentioned, whatever speed is too fast or too slow, it is not conducive to improve the effect. Thus, from this point, it is the key factor. Some studies by relevant researchers at home and abroad indicate that with wire feeding speed increment, Ca recovery ascends at first, and then descends; Ca recovery is depended on efficiency that molten steel absorbs added calcium. Lower addition, inclusions cannot be modified effectively; higher addition, calcium cannot be absorbed by molten steel completely and waste the remains, descends Ca recovery. Wire feeding speed not only is related to wire feeding depth, but also has a certain relation with calcium addition and absorption.
Argon blowing system:
During wire feeding process, argon blowing in ladle bottom not only mixes molten steel’s composition averagely, but also takes big-sized inclusions, and improves molten steel cleanliness, relieves the burden of calcium treatment. Argon blowing time and argon flow have a certain relation with inclusions behaviour and calcium treatment effect. Argon blowing parameters should be optimized on basis of volume of ladle and actual situation of technique. Regardless of argon blowing time or argon flow, it is not too long or too more.
Most of domestic steel plants utilize soft blowing argon technique before and during adding calcium process currently.
Amount of wire feeding:
It decides calcium treatment effect directly whether amount of wire feeding is appropriate or not. Amount of calcium feeding, it is one of the most paramount factors to impact calcium treatment process effect. Lower amount of calcium feeding will lead to non-ideal inclusions modification and clog the nozzle; while higher amount will generate high melting point inclusion——CaS and further deteriorate the phenomenon that nodules clog the nozzle. Relevant studies indicate that calcium remains ascends at first then tend to stay with amount of wire feeding increment. It implies calcium remains reach to saturation state.
With refined parameters, calcium treatment revolutionizes industrial processes, ensuring unparalleled efficiency and product excellence, shaping the future of manufacturing.
If you have any questions or needs, please contact us without any hesitation. We will revert as soon as possible.
