What is carbon additive? Carbon additive is a carbon or petroleum coke follow-up product of black or gray particles (or blocks) with high carbon content. The material is mainly coal and petroleum coke. The petroleum coke is divided into general calcined petroleum coke. (calcined coke or calcined coke) and graphitized petroleum coke. The carbon additive is used to reduce the oxygen content in the molten iron mainly during metal smelting and improve the mechanical properties of the casting. In the new synthetic cast iron smelting process, the amount of scrap steel used is greatly increased. By adding a carbon additive to adjust the carbon content of the molten iron, the production cost is greatly reduced while ensuring the quality of the molten iron.
Types of carbon additive
According to the existence form of carbon atoms, carbon additive can be divided into graphitized carbon additive and non-graphitized carbon additive. Graphitized carbon additive mainly includes graphitized petroleum coke and graphite electrode. Graphitized petroleum coke carbon additive is the most widely used in the foundry industry. The production process is to convert the raw material petroleum coke in a graphitization furnace through a high temperature of 2200-2600 °C, so that the carbon crystallization of the petroleum coke amorphous layer structure is transformed into The high-temperature heat treatment process of the three-dimensional ordered graphite crystal, that is, through the graphitization process, reaches the graphitization state. The non-graphitized carbon additive mainly includes: calcined petroleum coke, coal carbon additive, etc., calcined petroleum coke refers to petroleum coke heated at 1200-1500 ° C high temperature, the treatment temperature is low, and the crystal structure has not changed. Due to the high ash content and volatile matter, coal-based carbon additive is rarely used in electric arc furnace smelting. The indicators for measuring the quality of carbon additives are fixed carbon content, sulfur, volatile matter, ash, nitrogen content and water. After high temperature graphitization, the graphitized carbon additive has a much lower sulfur and nitrogen content than the non-graphitized carbon additive.
Carbon additive index: fixed carbon, ash, volatile matter
The fixed carbon of carbon additive is different from the carbon content. The fixed carbon value is calculated based on the moisture, volatile matter, ash and sulfur content of the sample, and the carbon content can be directly detected by the instrument. The fixed carbon content is high and the ash content is low, so the carbonization effect is better. The high ash content in the carbon additive generates a large amount of soot and slag during the smelting process, increases energy consumption, and increases the labor intensity of the slag.
Carbon additive index: sulfur
The sulfur content of ordinary calcined coke has a relatively high grade, generally less than 3% of sulfur to 0.1%, and the sulfur content of graphitized carbon additive is generally less than 0.05%. In ordinary cast iron, sulfur element has stable cementite and prevents the expansion of graphitization. In the production of ductile iron and vermicular graphite iron, a graphitized carbon additive with low sulfur content should be used. If the sulfur content is too high, the ball will be affected. The effect is to consume more spheroidizing agent and increase the production cost; the calcined petroleum coke carbon additive is used in the production of some gray iron castings because of the lower calcination temperature and higher sulfur content, generally less than 1%.
Carbon additive index: nitrogen content
Nitrogen content is an important indicator of the quality of carbon additive. In general, when the foundry purchases the carbon additive, the first is to pay attention to the price of the carbon additive; the second is the fixed carbon, sulfur, ash, volatile matter, and moisture content in the carbon additive, and less attention is paid to the nitrogen content. Ordinary calcined petroleum coke carbon additive, the calcination temperature is low, and the nitrogen and sulfur contents are high. When producing gray iron castings, the scrap steel itself will bring in a part of nitrogen. If the scrap is added in a large proportion, the amount of carbon additive will increase accordingly. If ordinary carbon calcined carbon additive with high nitrogen content is used, the molten iron is used in molten iron. The nitrogen content will increase significantly. Excessive dissolved nitrogen in the molten iron hinders graphitization, increases the stability of the carbide, promotes the formation of D-type graphite, improves the hardness, and deteriorates the processing properties of the casting.
For gray cast iron, the proper amount of nitrogen can shorten the length of the graphite sheet, increase the degree of bending, passivate the end, reduce the aspect ratio, stabilize the pearlite of the matrix, refine the grain structure and improve the tensile strength of the casting. And the role of hardness. According to the data, when the iron is N>0.012%, there is a possibility of nitrogen hole defects in the casting. Nitrogen pores are commonly found in the interior, surface or near surface of castings. They are round, rectangular and irregular in shape and are one of the common defects in casting production. The graphitized carbon additive is subjected to high-temperature desulfurization and denitrification treatment, and the content of nitrogen and sulfur is very low. The content of molten iron in the molten iron using graphitized carbon additive is generally low.
Factors affecting the absorption rate of carbon additive: The factors affecting the absorption rate of carbon additive are mainly the way of adding carbon additive, the chemical composition of molten iron, the temperature of molten iron, and the particle size of carbon additive.
“China (Shanghai) International Foundry Exhibition, China (Shanghai) International Casting Products Exhibition” was founded in 2005 and has been successfully held for 13 sessions. The exhibits cover castings, casting molds, foundry materials, foundry equipment and castings. Developed into one of the high-profile, high-level, most professional and most authoritative brand exhibitions in the industry. The exhibition actively responded to the call of national policies, and advocated enterprises to take an innovative and efficient green casting road, which played an active role in promoting the healthy development of industry science and nature and social harmony.
Time: November 1-3, 2018
Venue: Shanghai New International Expo Center (2345 Longyang Road)
Shanghai New International Expo Center (SNIEC) is jointly invested by Shanghai Lujiazui Exhibition Development Co., Ltd. and German Exhibition Group International Co., Ltd. (members include Hannover Messe GmbH / Düsseldorf Messe GmbH / München Messe GmbH) put up. As the first exhibition center for Sino-foreign joint ventures, Shanghai New International Expo Center has been built into one of the most successful exhibition centers in China.
East China Foundry Association
Shanghai Automobile Industry Association Automobile Foundry Branch
China Institute of Metals
Baowu Iron and Steel Group Co., Ltd.
Shanghai Metal Society
Shanghai Mechanical Engineering Society
Shanghai Huaye Exhibition Co., Ltd.
Shanghai Shenshi Exhibition Service Co., Ltd.
Shanghai Huaye Exhibition Co., Ltd.
Address: Room 402, Hujin Building, 240 Tianmu Middle Road, Shanghai
Tel: 021-6919 0370
Fax: 021-6129 4607
Exhibitor Contact: Mr. Lin Sen QQ: 1060727407
Mobile: 13524321255 (WeChat with the same number)
Visit Contact: Ms. Wang Fang QQ: 32800869
Mobile: 13162692801 (WeChat with the same number)
The 14th China (Shanghai) International Foundry Exhibition and the 14th China (Shanghai) International Casting Products Exhibition will be held on November 1-3, 2018 at Shanghai New International Expo Center (2345 Longyang Road). . At that time, 500 foundry and related companies will gather, with an exhibition area of 45,000 square meters and more than 40,000 professional visitors. This year's exhibition will invite Chinese and world foundry manufacturers, materials and equipment giants to showcase new products, new technologies and new equipment with the requirements of “internationalization, specialization and high level”, thus helping the industry's top management to fully understand the global foundry industry chain. The latest trend, while creating a one-stop shopping platform for products, materials and equipment for the audience!
The 13th China (Shanghai) International Foundry Exhibition 2017 and the 13th China (Shanghai) International Casting Products Exhibition were successfully held in Shanghai New International Expo Center, which lasted for 3 days. It has gathered 520 exhibiting companies from 20 countries and regions, attracting 32,521 professional visitors from home and abroad, 13 foreign professional purchasing groups, and successfully held more than 10 casting industry technical seminars in the same period.
1. Cast steel, cast iron, stainless steel castings, non-ferrous alloy castings, aluminum castings, copper castings, ductile castings, wear-resistant castings; (precision casting, sand casting, investment casting, lost foam casting, centrifugal casting, gravity casting, high\ Low pressure casting, special casting, etc.).
2. Automobiles, motorcycles, machine tools, ships, wind power, construction machinery, rail transit, heavy machinery, mining machinery, textile machinery, printing machinery, medical machinery, general machinery, power transmission and transformation, electronic communication, petrochemical, construction hardware Castings such as pipeline pump valves, pipe fittings, municipal engineering, urban art, etc. and aluminum/magnesium/zinc/copper alloy die castings.
◆ Foundry equipment
1. Smelting and auxiliary equipment: cupola, electric furnace, electric resistance furnace, aluminum alloy melting furnace, magnesium alloy melting furnace, vacuum melting furnace, electric arc furnace, LF/AOD/VOD refining furnace, automatic pouring machine, transfer package, automatic feeding equipment , cooling towers, etc.
2, modeling / core and auxiliary equipment: box molding equipment, box-free molding equipment, resin sand molding equipment, shell molding equipment, core making machine and core center, modeling / core gas processing equipment, resin and additive quantification Equipment, core processing equipment (retouching, coating, drilling, etc.), rapid prototyping equipment (3D printing / moldless core making).
3, sand treatment / old sand regeneration and auxiliary equipment: falling sand machine, sand mixer, sand cooling equipment, magnetic separation equipment, dust removal system, chrome ore / silica sand sorter, zircon sand / silica sand sorter, old sand regeneration Equipment, etc.
4, cleaning equipment and auxiliary equipment: throwing / shot blasting equipment, automated casting finishing grinding equipment, electrochemical cleaning equipment.
5, special casting equipment: investment casting, lost mold (real) and V method casting, metal gravity casting, centrifugal casting, low pressure casting, differential pressure casting.
6. Measurement and testing equipment: rapid analyzer for chemical composition before furnace (direct reading spectrometer, CE thermal analyzer, CS analyzer), sand detector online detector, coordinate measuring instrument, thermometer, thickness gauge, endoscope Mirror, hardness tester, non-destructive testing equipment (linear accelerator flaw detector), mechanical performance testing machine, etc.
7. Others: casting, forging, die-casting robot (manipulator), automatic control system, casting mold and tooling processing equipment, tools, measuring tools, robots and testing equipment (tools), heat treatment equipment, infiltration equipment, welding equipment, surface Treatment and painting equipment, dust removal technology and equipment, industrial air conditioning, ventilation equipment, negative pressure exhaust fans, industrial cooling fans.
8, after processing equipment: CNC lathes, machining centers, milling machines, grinding machines, drilling machines, polishing machines, sand blasting machines.
◆ Casting materials
Ferroalloy, non-ferrous metal, foundry coke, refining agent, inoculant, spheroidizing agent, creeping agent, slag removing agent, quartz sand, coated sand, chromite sand, orb sand, bentonite, coal powder, recarburizer, Casting resin, curing agent, paint, refractory for casting, silica sol, wax, insulation riser, filter, steel shot, repair paste, etc.
Shanghai Aideer Precision Casting Co., Ltd.
The exhibition is good, our company has been participating for 4 consecutive years.
Shanghai Zhongzhen Nonferrous Metal Casting Co., Ltd.
This is not the first time we have participated in the International Casting Exhibition hosted by Huaye Company. The scale of the exhibition is growing every year. The quality of the audience of each exhibition is very high, which is very helpful for us to develop new business, especially overseas business. Here, I wish the exhibition better and better!
Taicang Yajin Lans Machinery Co., Ltd.
At the beginning of the exhibition, because the gods were not beautiful, they were more worried about the number of visitors. After the launch, the visitors will be in a constant stream. The booth of our company is even more popular. The 500 documents brought by the first day will be finished. I really want to thank the organizing committee for their efforts.
Jiangsu Huaye Technology Co., Ltd.
By participating in this exhibition, we have gained important target customers.
Shiyan Well-known Industrial Development Co., Ltd.
We have participated in the Shanghai Foundry Exhibition for three consecutive years. The exhibition has received more than 20 new customers and the results are very satisfactory. The organizer's booth design and exhibitor's customer service are also in place, which is the guarantee for our successful participation. We look forward to seeing the foundry exhibition next year.
Suzhou Xiaweiyi Energy Saving Machinery Co., Ltd.
CSFE2014 brings together a large number of casting products and equipment companies to provide us with a high-quality environment to display the company's products and services, while creating a platform for communication with other well-known companies.
Huzhou Nanfeng Machinery Manufacturing Co., Ltd.
The exhibition is rich in form, and Huaye is the third time to participate in the service and enthusiasm of the organizer. I hope to continue to organize more and better target customers to come to the scene to meet with us.
Yingda Industry (Shanghai) Co., Ltd.
The exchanges and interactions with professional visitors have benefited us a lot, further understanding the needs of the industry, and making friends with friends. I wish the exhibition to become a casting exhibition with global influence as soon as possible.
Hanshan County Machinery Casting Association
This exhibition is based on the theme of environmental protection, energy conservation and emission reduction. It has forums, exhibition areas and rich and colorful, which provides a good platform for relevant industry exchanges and is conducive to the development of green environmental protection.
East China Foundry Association
The exhibition is professional and the process is clear. The communication between us and Huaye is also very smooth. While supporting the work of the association, we have also demonstrated our image and wished the foundry exhibition more and more success!
CHUNHO casting co.,Ltd(KOREA)
Congratulations to the organizers of Shanghai Foundry Exhibition - all relevant personnel of Huaye Company and all exhibitors, this is an excellent exhibition event. We are very happy to see so many companies attending the show.
Shanghai Shengdeman Casting Co., Ltd.
The effect is very good. I feel that the scene is very popular. The on-site customers are more targeted. I saw the customers I want to see and played a very good publicity effect. The green casting and energy-saving and emission reduction forum held at the same time was also very successful. Similar hopes can continue to participate.
Suzhou Zhenwu Electric Furnace Co., Ltd.
The exhibition performed well and was very satisfied with the service of the organizers. It achieved the expected goals and is looking forward to continued participation next year.
Jiangsu Lutong Furnace Co., Ltd.
As an old exhibitor, we feel that the scale of this casting exhibition is very large. The service of the organizer of the exhibition is very in place, very intimate and convenient to communicate. I hope to inform us as soon as possible to make better preparations.
Ningbo Yinzhou Qianming Casting Co., Ltd.
This year is the second time that our company has participated in the foundry exhibition. Personally, this exhibition is large in scale and professional. Through this platform, we can not only promote our products, but also let everyone know about our brand. In the future, we will also choose a larger booth to exhibit.
Zhejiang Wanfeng Technology Co., Ltd.
The three-day “casting and die-casting exhibition” has been successfully completed. As the exhibitor of this exhibition, the latest casting robot products are unveiled. The exhibition was grand in scale, and the exhibitors were highly representative. Exhibitors and visitors from all over the world showed great enthusiasm for the exhibition.
The use of recarburizers, as the name implies, is to increase the content of carbon. Its main purpose is to increase the carbon content lost during the steelmaking process. If the carbon content does not meet the expected requirements during the steelmaking process, a certain proportion is required. The recarburizer enhances the carbon content of the molten steel and smelts the ideal steel.
There are many kinds of raw materials for recarburizers, and the production process is also different. There are wood carbons, coal carbons, petroleum cokes, etc., while petroleum cokes are divided into calcined coke recarburizers and graphitized recarburizers. The current mainstream recarburizer.
The calcined petroleum coke recarburizer refers to the calcination of the raw material petroleum coke, and the temperature is controlled at 1250～1380°C. During the calcination process, the structure and element composition of the petroleum coke undergo a series of deep changes, thereby improving their physics. Chemical properties.
Why is petroleum coke calcined?
The purpose of calcination:
1. Eliminate volatiles and moisture in petroleum coke raw materials. After calcination, the volatile matter is 0.5% or less, and the water content is 0.3% or less.
The calcined volatiles and moisture represent the degree of calcination, which does not require secondary shrinkage and crack formation during calcination.
2. Improve the density and mechanical strength of petroleum coke raw materials. The true density is 2.00 g/cm3 or more.
The true density of the calcined coke affects the true density of the final product, and the mechanical strength is low. The bulk density is low, which affects the molding. The main performance is difficult to form. The height of the green block does not meet the requirements within the required time, which affects the operation of the aluminum electrolytic cell.
3. Improve the electrical conductivity of petroleum coke raw materials.
The calcined coke specific resistance affects the final product resistivity.
4. Improve the chemical stability of petroleum coke raw materials. Improved oxidation resistance.
Graphitized petroleum coke recarburizer is a process of treating petroleum coke into high temperature by graphite. This process is the process of energizing petroleum coke and then calcining at a high temperature of 3000 degrees, so that the carbon molecular form of petroleum coke is changed from irregular arrangement to hexagonal uniformity. In the way of arrangement, petroleum coke in this way can be better decomposed in molten iron to improve the effect of carbon absorption. Graphitized petroleum coke is the best refining agent for smelting. In the steelmaking industry, to produce good steel, there must be good raw materials, including good recarburizers, and graphitized petroleum coke is the best recarburizer. In the absence of graphitized petroleum coke, the graphite electrode has less scrap and higher price, which not only increases the cost of steelmaking, but also restricts the development of the steel industry. The appearance of graphitized petroleum coke breaks this bottleneck.
How much is a ton of recarburizer? The price of recarburizer depends on the specific indicators and particle size, such as the amount of fixed carbon, the amount of sulfur, the size of the grain, etc., in order to report the exact price, as well as the source of goods and freight, etc., Foshan Jitian Foundry Co., Ltd. mainly supplies calcined After the coke recarburizer and graphitization recarburizer, for Guangdong, Hunan, Guangxi, Jiangxi, Fujian and other provinces, customers are welcome to contact 2018 the most new carbon agent price, indicators and granularity!
Calcined coke recarburizer (petroleum coke): 2018.09.02 This week, the mainstream price of calcined coke recarburizer market remained stable, and individual companies offered slightly higher prices, and the market was stable. Raw materials: The price of domestic medium-high sulfur calcined coke has risen this week, with a concentration of 70-150 yuan/ton. The main reason for the increase in coke price is supply reduction and cost increase. In terms of raw materials, domestic petroleum coke prices are still rising mainly this week. The local refinery coke price has started to fall slightly on Wednesday. On the supply side, the supply of calcined coke in Shandong has decreased this week, mainly due to the impact of environmental supervision. Shandong this week The operating rate of Dongying calcined coke was significantly reduced. Most enterprises cut production by half and one was shut down. The production of calcined coke in other parts of Shandong has not been affected significantly. The fluctuations of calcined coke in Jiangsu and Hebei this week are not significant. Market outlook: It is expected that the market price of domestic medium and high sulfur calcined coke will be stabilized and stabilized next week.
Graphitized petroleum coke recarburizer (petroleum coke): 2018.09.02 This week, the price of graphitized petroleum coke recarburizer was stable, the market spot was abundant, and the shipment situation was general. Among them, the production of individual enterprises in Henan and Xinjiang was suspended due to environmental protection, and the operating rate fell. In addition, the graphitization enterprises of anode materials in the anode market will be put into production in the second half of the year. It is expected that the output will be released one after another, affecting the overall supply of graphitized recarburizer market. The concentration of negative electrode enterprises in Inner Mongolia is high, and the graphitization and recarburizer processing enterprises have also been transferred, and the market concentration has increased. The Jiangsu area is operating normally and the shipments are good. The orders are mainly for the old customers. The anode materials processing enterprises in Qinghai, Lanzhou, Ningxia, Inner Mongolia and other regions have higher activity and increased production.
Steelmaking recarburizer for casting, cast iron, cast steel, cast will have a requirement for carbon, then recarburizer just as its name implies is to increase the carbon content in liquid iron, and, for example, commonly used in smelting furnace charge for pig iron, scrap steel, back to the furnace charge, iron carbon content is high, but relatively scrap purchase price is higher section, so adding scrap supply, reduce the quantity of pig iron, add recarburizer, can have certain effect to reduce the casting cost.
Below by yu da energy conservation for you to introduce.
In the process of smelting, the carbon content of steel does not meet the requirements of the top period due to improper mixing or charging and excessive decarbonization, etc. At this time, carbon is added to the steel solution.
Common carbon - increasing agents are carbon - increasing pig iron, electrode powder, petroleum coke powder, charcoal powder and coke powder.In converter smelting, high - carbon steel, the use of oil coke containing few impurities as a carbonizing agent.
The requirements for the top blown converter steelmaking use of the carburizer are high fixed carbon, low ash, volatile and sulfur, phosphorus, nitrogen and other impurities, and dry, clean, moderate particle size.
Recarburizer is suitable for smelting in induction furnace, but its application is different according to the technical requirements.
(1) in the smelting process of medium-frequency electric furnace, the use of carbon intensifier can be added to the lower part of the furnace with the material in accordance with the requirements of proportion or carbon equivalent, and the recovery rate can reach more than 95%;
(2) if the lack of carbon adjustment, the first dozen net furnace slag, plus carburant, by raising the temperature of molten iron, or artificial electromagnetic stirring to dissolve carbon absorption, the recovery rate is around 90%, if the low-temperature carbonization process, the melt furnace charge only part of the molten iron liquid under the condition of low temperature, all recarburizer one-time in liquid iron, at the same time with solid charge to press it into the liquid iron don't let it show liquid iron surface.
This method can increase the carbon content of iron liquid by more than 1.0%.
Graphitized Petroleum Coke 0.2-2mm carbon additive
Date: July 02, 2018
Volatile Matter: 0.93%
Fixed Carbon: 98.90%
Calcined petroleum coke is a kind of petrochemical product, whose raw materials is green petroleum coke.
It is widely used to produce graphite electrode, graphite blocks, brakes pads and other carbon products.
It’s also be used as carbon additive in some steel and aluminum plants.
Graphitized Petroleum Coke 1-5mm carbon additive
Date: June 29, 2018
Volatile Matter: 0.99%
Fixed Carbon: 98.32%
The main application of calcined petroleum coke is in the production of anodes for the Aluminum Smelting process. 70 - 80% of calcined petroleum coke is for the Aluminum Industry. The reason for use in the Aluminum Industry is for conductivity.
Another use for calcined petroleum coke is TiO2 production which accounts for about 15% of the CPC consumption. The reason for use in TiO2 is for its oxidizing effect.
Graphitized Petroleum Coke 1-5mm carbon additive
Date: June 11, 2018
Volatile Matter: 0.53%
Fixed Carbon: 98.97%
Calcined petroleum coke is a high purity carbon material produced by heating green petroleum coke to drive off moisture, volatile matter, and impurities and to increase its electrical conductivity, which is used to improve the carbon content in steel-making and ductile iron foundry. It is widely used to produce graphite electrode, graphite blocks, brakes pads and other carbon products. it can also be used as carbon additive in some steel and aluminum plants, another, it is used in refractory, insulation, filler,etc. We can supply different grades of Calcined Petroleum coke.
In recent years, more and more factories use the induction electric furnace for cast iron, but usually only the metal material can not keep the carbon content in iron, so that's why it need the recarburizer. For the induction electric furnace, special the intermediate frequency furnace, adding the carbon material is important link for smelting.
1. Shoul choose the carbon additive(calcined petroleum coke) with low nitrogen
The usual nitrogen content in cast iron liquid is below 100 ppm. If the nitrogen content exceeds this concentration (150-200 ppm or higher), it is easy to cause cracks, shrinkage or loose defects in the casting, and thick-walled castings are more likely to occur. This is caused by an increase in the amount of recarburizer added when the proportion of scrap steel increases. Coke-based recarburants, especially bitumen coke, contain large amounts of nitrogen. The graphite graphite has a nitrogen mass fraction of 0.1% or less or a very small amount, and the pitch pyrolysis mass fraction is about 0.6%. If 2% of the recarburizer with a mass fraction of 0.6% nitrogen is added, this increases the nitrogen content by 120 ppm. A large amount of nitrogen is not only liable to cause casting defects, but also nitrogen can promote pearlite compaction, ferrite hardening, and strongly increase strength.
2. Ways to adding the recarburizer
The stirring of molten iron can promote carbon addition. Therefore, the medium frequency induction electric furnace with weak stirring force is much more difficult to increase carbon than the power frequency induction electric furnace with strong stirring power. Therefore, the medium frequency induction electric furnace has the carbonization speed and the melting rate of the metal charge The possibility.
Even in a power-frequency induction furnace with high stirring power, the carbon-increasing operation cannot be ignored. This is because, from the schematic diagram of the induction furnace melting, there is a stirring iron flow separated vertically in the induction furnace, and there is a dead angle near the furnace wall at the boundary. The graphite cluster which stays on the furnace wall and adheres cannot be melted into the molten iron without excessive temperature rise and long-term iron liquid heat preservation. Excessive heating of the molten iron and long-term heat preservation will increase the degree of supercooling of the molten iron and increase the tendency of the cast iron to become white. In addition, for medium frequency induction furnaces that generate a strong induced current near the furnace wall, if molten iron is drilled between the graphite clusters attached to the furnace wall, the drilled metal is melted during the next furnace smelting, resulting in erosion. And damage the furnace wall. Therefore, in the case where the proportion of scrap steel is high and the amount of recarburizing agent is added, it is necessary to pay more attention to the addition of the recarburizing agent.
The addition time of the recarburizer cannot be ignored. If the addition time of the recarburizing agent is too early, it is easy to adhere to the vicinity of the bottom of the furnace, and the recarburizing agent adhering to the furnace wall is not easily melted into the molten iron. On the contrary, if the joining time is too late, the timing of carbon increase will be lost, causing the smelting and heating time to be slow. This not only delays the time of chemical composition analysis and adjustment, but also may cause harm due to excessive temperature rise. Therefore, the recarburizing agent is preferably added little by little during the process of adding the metal charge.
The so-called recarburizer is to increase the content of carbon in the molten iron after it is added. Therefore, the fixed carbon content of the recarburizer must not be too low. Otherwise, to reach a certain carbon content, it is necessary to add a high carbon content. With more samples of recarburizer, this undoubtedly increases the amount of other unfavorable elements in the recarburizer, so that the ferrofluid can not obtain a better return.
Low levels of sulfur, nitrogen, and hydrogen are key to preventing the production of nitrogen holes in castings. This requires that the nitrogen content of the recharging agent be as low as possible. The other indicators of recarburizers, such as moisture, ash, and volatiles, the higher the amount of fixed breakage, so the high fixed carbon content of these harmful ingredients must not be high. For different smelting methods, furnace types, and sizes of smelting furnaces, it is also important to select an appropriate particle size of the carbon reductant, which can effectively increase the absorption rate and absorption rate of the recarburizer by the molten iron and avoid excessively small particles. Caused by oxidative damage to the breaker. The particle size is preferably: 100 kg furnace less than 10 mm, 500 kg furnace less than 15 mm, 1.5 tons furnace less than 20 mm, 20 tons furnace less than 30 mm. In the smelting of converters, when high-carbon steels are used, recarburizers containing little impurities are used.
The requirement for the recarburizer for top-blowing converter steelmaking is that the fixed carbon should be high, the content of ash, volatile matter and sulfur, phosphorus, nitrogen and other impurities should be low, and it should be dry, clean, and the grain size should be moderate. Its fixed carbon C> 97%, volatile matter <1.0%, S <0.5%, moisture <0.5%, particle size in l-5mm. The particle size is too fine to be easily burned, and it is too thick to float on the surface of the molten steel and is not easily absorbed by molten steel. The particle size of the induction furnace is 0.2-6mm, in which the steel and other ferrous metals have a particle size of 1.4-9.5mm, the high carbon steel requires low nitrogen, the particle size is 0.5-5mm, etc. The concrete need to be based on the specific furnace type smelting workpiece The details of the types and so on are specifically judged and selected.
Name: Owen Zhang
Mobile： 0086-182 1805 1155
Wechat: 182 1805 1155
Whatsapp: 0086-182 1805 1155
Add: Foshan, Guangdong, China