Key technology of smelting stainless steel in combined blowing converter

Hot metal dephosphorization technology. When the hot-smelting converter uses molten iron to smelt stainless steel, the dephosphorization of the molten iron is first carried out, or the dephosphorization is carried out by a mixed iron car, or the dephosphorization is carried out in a double-blown converter.
Converter thermal compensation technology. Since stainless steel is a high-alloy steel, it is necessary to add a large amount of cold alloy during smelting. For example, only the sensible heat and oxidation heat of molten iron are used to make steel in the converter, and the heat energy is obviously insufficient. According to the calculation, the heat shortage of the stainless steel SCTS304, SC1S316, SC1S410, SC1S420 and SUS430 in the whole molten iron condition is about 11.5%, 14.6%, 6.1%, 8.0% and 5.4%, respectively, for which the development cost is low. Technology is an indispensable technology for smelting stainless steel in a combined blown converter. Nowadays, the thermal compensation technology of the secondary combustion (called PC gun) of the top of the furnace and the broken coke block (granule) and the double-flow oxygen lance are generally used.

Thermal compensation technology for crushing coke blocks (grain) on the top of the furnace: The thermal compensation technology using broken coke particles as a heat source has the following advantages over the method using FeSi as a heat source:

a. The remaining coke blocks (granules) remaining in the steel plant can be used, and the source is wide and the price is cheap;
b. Even if used in large quantities, the amount of slag increases a lot;
c. The generated CO gas can be effectively utilized as a heat source.
Thermal compensation through secondary combustion: The secondary combustion thermal compensation technology of the dual-flow oxygen lance can tap the potential of chemical heat in the furnace, thereby reducing the amount of coke thermal compensation, thereby shortening the blowing time and oxygen consumption.

The use of a dual-flow oxygen lance increases the secondary combustion rate of CO.
The secondary combustion rate is increased by controlling the ratio of the oxygen amount of the main and auxiliary oxygen holes. The secondary combustion rate is the highest when the ratio of the secondary pore oxygen to the main pore oxygen is 20%. In addition, increasing the height of the lance is also beneficial to increase the secondary combustion rate.

Since the main alloy of stainless steel, the inscription element, is easily oxidized at high temperatures, it is necessary to have sufficient decarburization capability in the converter to smelt stainless steel, and also to suppress the oxidation loss of chromium.

According to the principle of metallurgy, the higher the temperature of molten steel, the better the decarburization reaction; the lower the partial pressure of CO in the converter is beneficial to the reduction of chromium, and the oxidation loss of chromium can be suppressed while blowing oxygen decarburization. In order to meet the requirements of thermodynamic theory, the converter is usually diluted or refined to dilute the concentration of CO generated in the converter due to the decarburization reaction with a large flow of bottom-blown inert gas to reduce the partial pressure of CO. At the same time, it can also promote the stirring of molten steel and accelerate the decarburization reaction. In addition, in the control of molten steel temperature, we must first overcome the problem of insufficient heat source, and then effectively achieve high temperature (≥1700 °C) operation.
Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source:Key technology of smelting stainless steel in combined blowing converter
Company name:Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

The importance of correct refractory design

As we all know, the refractory design remains the most fundamental factor in all furnaces construction. Refractory design details and proven technology consideration is of paramount importance to come up with an optimum furnace life and to maintain productivity in the life span of the furnace lining.

The failure to produce a technically or operationally durable refractory design lining could give rise to premature deterioration of the refractory lining and furnace shell.

The premature failure of the furnace lining will lead to extensive heat losses, furnace bath shift, change in tap hole orientation and alteration of the Pitch Circle Diameter. In this way, the pre-design of refractory lining is very important, we must pay attention to every details, finding out the most suitable refractories for each part.
Our technical team can give you a perfect design which is suitable for your furnaces according to specific needs, please contact us freely if you’re interested.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source:The importance of correct refractory design
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

Precautions when baking furnace

1. The furnace charge must be required, uniform medium and small refractory materials are needed, and the oven fabric must support the steel pan liner.

2. Carefully and carefully guarding the oven in the process of gradual feeding, and finding that the charge and steel pan are in time for fire treatment, the steel pan should be made to not melt before the molten steel is in place.

3. The first furnace of the oven should try to make the location of the molten steel close to the furnace mouth platform in order to facilitate the optimization of the sintered layer and to form the sintered layer of the upper furnace wall as much as possible so as to prevent the sand from falling when the upper mouth is not sintered to remove the residual steel pot. After the furnace is fused, the holding temperature must meet the requirements in order to increase the thickness of the sintered layer.

4. Barbaric operation is strictly prohibited.

5. Try to use less slag, more clean scrap, and use a slag treatment when the amount of slag is large.

6. Minimize soaking time when using high-Mn steel grades. Pay attention to the power supply curve of the cold furnace so as to close the cracks. Repair must be fine, as far as possible between the two refractory materials.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.

Article Source:Precautions when baking furnace
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

On May 1, the VAT rate in the manufacturing industry will be lowered

From May 1st, 2018, the value-added tax rate for manufacturing and some other industries will fall from 17% to 16%.

The tax cuts have really benefited the refractory companies.

Upstream, downstream, and surrounding companies in the refractory industry will all be the beneficiaries of this tax cut. This VAT policy adjustment is generally expected by the market and companies. The tax cut exceeds the market expectation, which will bring huge benefits to refractory raw materials companies. This shows that China's value-added tax has been steadily advancing along the established modern value-added tax reform goals. Raise the annual sales standard of small-scale taxpayers, so that more small and medium sized refractory companies and start-ups can enjoy tax benefits.

Changxing refractory provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ceramic fiber felt, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, magnesia carbon brick, clay refractory bricks and other refractory products.
Article Source:http://www.chinafirebrick.com/Company_News_163.html
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

European electric fused magnesia prices rose by more than 50%

The price of fused magnesia in Europe has exceeded $1000 per ton this week. As China's product prices continue to rise and supplies are scarce, international demand for related products is also increasing.There have many refractory news and refractory products information on web. You can read more refractory products and know more refractory materials information. Because our website has many kinds of refractory news and industry news. Chinafirebrick provides refractory products, calcium silicate products, castable & mortar, china refractory brick, ladle & tundish nozzle, ceramic fiber with high quality for you. Such as high alumina refractory bricks, Magnesia Carbon Brick, clay refractory bricks and other refractory.
At the same time, the European magnesia market as much as possible to prevent the rapid rise in prices, until the second quarter of this year, China's fused magnesia basically stopped, so that the European fused magnesia prices doubled now.
According to the British industrial minerals magazine this week the latest quotation shows Europe fused magnesia international trading price range, FOB Europe price was 1000-1200 dollars per ton. Before the chain FOB Europe's price range of $640-750 per ton, the price rose 58%.

In fact, in June of this year, the international price of European magnesia has been from the beginning of the $480-650 per ton, rose to $640-750 per tonne. This is mainly due to insufficient supply of spot fused magnesia. A European manufacturer said, our basic fused magnesia has been sold out in the other months. One vendor said, we are only small quantities of goods provided. Third producers said, we are unable to provide the goods beyond the contract at present. Nevertheless, the buyer was willing to buy at the price.

Production in Europe has been produced and settled on the basis of the annual requirements of the customer, which greatly reduces the surplus in the stock market, but the situation in China has made market supply worse.

China and interrupt the production due to environmental inspection, in the past few months, cut or stop production enterprises continue to increase productivity, and slow recovery. In addition because the explosive restrictions lead to refractoryraw materials to mining, is also facing the shortage, it also makes some factories unable to normal production.

With the development of time, the market becomes very obvious, customers find it difficult to find the right products from China, they will search other countries.
As early as July this year, a number of European suppliers indicated that the order was full, but the inquiry continued, and many suppliers were fully operational, but they were still unable to meet the shortfall in China.

The accumulation of materials are not only fused magnesia, and heavy fire and light burned magnesia, but is mainly native to Europe. It also makes the customer in Europe in the first half of this year than the price of the China stable lot. Different grades of calcined tight supply, but the light burned magnesia was better at present. The shortage is fused magnesia supply.

Prices of other European magnesia have remained essentially unchanged:
Light burned magnesia, agricultural, CIF European port, 240-300 euros per ton;
Fused magnesia, Electrotechnical grade, ex factory price US $1500-2450 per ton;
Magnesite raw material, silica content of not more than 3.5%, FOB, Eastern Mediterranean, 65-80 euros per ton;

Prices in North America are basically stable:
Fused magnesia, electrical grade, ex factory price US $1700-2500 per ton.
Fused magnesia, refractory grade, FOB us, $900-1400 per ton.

There have many kinds of refractory products in our factory. What's more, there have magnesia carbon brick and other magnesium products products in our factory. Welcome to view our website and contact us anytime.
Article Source:European electric fused magnesia prices rose by more than 50%
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

Prevention and elimination of forging cracks (1)

The principle of preventing crack

1. There have many kinds of refractory products in our factory, such as fire brick china, refractory products, calcium silicate products, castable, etc. Chemical components of material should strictly comply with the standards of harmful elements,such as S, P, O, N, CU, AL and other easy to form inclusion elements and An, Sb and other trace elements should be controlled. For example: 1Cr18Ni9Ti austenitic stainless steel, because Ti content exceed the standard will lead to steel ferrite’s increases that caused by forging crack.
2. To strictly control the smelting and casting process. This is to improve the purity of steel, eliminate the metallurgical defects, an important link to prevent crack will occur. Practice has proved that the inclusions in steel and presents lumpy aggregation, coarse grain and grain boundary fragility and blank with micro crack and subcutaneous bubbles, cracks easily damaged.
3. When forging, it is necessary to maintain a good stress state, such as changing the free forging punching into die extrusion forming to improve the stress state, so as to prevent the formation of cracks.
4. Strictly control the deformation temperature. Low temperature hardening, serious plastic decrease; the temperature is too high, overheated, burning, plastic will fall, will be?likely to produce cracks. Only fully of recrystallization interval in softening, is generally a single organization, less possibility of forging crack.
5. Deformation rate has a great impact on the low plasticity material, should be based on the specific material selection of suitable forging equipment, in order to prevent the fracture, such as forged MB5 magnesium alloy in the hammer is easy to crack, and in the press forging is not cracked, the reason is the recrystallization of magnesium alloy under high speed slow, easy deformation and easily broken. Changxing refractory provides refractory products, calcium silicate products, castable & mortar, refractory fire brick, ladle & tundish nozzle, ceramic fiber with high quality for you.

Article Source:Prevention and elimination of forging cracks(1)
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

Pay attention to the price of magnesia

In 2017, the state canceled 10% of export tariffs on magnesia, light burning magnesite and graphite. The average export price of sintered magnesia, fused magnesia, light burning magnesite and graphite fell by 21.37%, 14.46%, 20.79% and 19.31% respectively in January. This is basically a 10% reduction in export tariffs and a 20% drop in product prices. While the domestic price of similar products are rising, the main reasons of rising are: First, the increase of the national environmental remediation efforts, shut down non-standard kiln, resulting in decreased production of refractory raw materials; Second, the prices of high-quality ore rise, then the cost of raw materials production rise. But the export price of raw materials fell without any reason, the export enterprises should pay high attention to this phenomenon.

In short, the business situation is still grim, but the challenges and opportunities coexist. While coping with the challenge, refractories production enterprises should seize the opportunity at the same time, put in effort to improve industrial concentration, standardize the market order, enhance the industry's overall competitiveness and quality of business, and make contribute to the industry's stable and healthy development.

Article source: Pay attention to the price of magnesia

Why not to buy fire bricks from chinafirebrick ?

Changxing Refractory is a Chinese leading refractory and oil fracturing proppant manufacturer & supplier with a wide range industries in high temperature field . From a refractory bricks manufacturing factory, Changxing has become a professional manufacturer with various refractory materials and fire brick both in domestic and international market during 30+ years, whose customers covers North America, Middle East, Asia, Africa, etc.
1. Reduction in physical properties – Improper water content leads to a reduction in the physical properties associated with a monolithic refractory material. This can decrease the lifespan of the refractories as well as create issues for the end user throughout the time period in which they are in use. In many cases, end users select more costly refractories in order to acquire higher quality materials. The improper addition of water can completely negate this additional spend. In many cases leading to performance, that is inferior to properly mixed lower quality materials.
2. Increased set-up time – Materials in which too much water has been added will not set-up at the rate which they were designed to. In some cases, they may not set-up at all and may remain soft, spongey, or grainy. This may lead to the need to remove and re-cast the materials causing long and expensive delays. Furthermore, the rate at which monolithic refractories cure has an impact on the physical properties achieved. Accelerating and decelerating this reaction can have negative implications.
There are ways to insure that materials are properly mixed. These methods include adequate training of the workforce, proper communication, have the mixing and use instructions available during an installation, have proper measuring devices available, and the use of mixing logs and even third party inspectors.Changxing has a production line, which is base on oil & gas applied ceramic proppant, and also with 3 factories focusing on all kinds of refractory materials used for iron & steel casting, cement,fire bricks glass petrochemical and ceramics industries. With abundant sources and professional techniques, Changxing Refractory would like to build a reliable and efficient platform for customers all over the world.