What is low temperature casting, continuous casting The key to low superheat casting is

Low-temperature casting is a method of plastic processing. In the early days of casting, a liquid monomer or prepolymer (see polymer) was injected into the mold under atmospheric pressure, and then polymerized and solidified into a product with the same shape as the inner cavity of the mold. At the beginning of the 20th century, phenolic resins were first molded by the casting method.

Casting molding generally does not apply pressure, the strength requirements of equipment and molds are not high, the size of the product is less restricted, and the internal stress in the product is also low. Therefore, the production investment is small, and large parts with excellent performance can be made, but the production cycle is long, and mechanical processing must be carried out after molding. On the basis of traditional casting, methods such as casting, embedding casting, pressure casting, rotary casting and centrifugal casting are derived.

Perfusion. The difference between this method and casting is that the product is taken out of the mold after casting; However, the mold is an integral part of the product itself.

Inlay. Various non-plastic parts are placed in the mold cavity and solidified with the injected liquid material to encapsulate it. Pressure casting.

A certain pressure is applied to the material during casting, which is conducive to injecting viscous materials into the mold and shortening the filling time, which is mainly used for epoxy resin casting. Rotary casting. After the material is injected into the mold, the mold rotates around a single or multi-axis at a low speed, and the material is distributed on the inner wall of the mold cavity by gravity, and is shaped by heating and curing.

It is used to manufacture spherical, tubular and other hollow products. Centrifugal casting. A certain amount of liquid material is injected into a mold that rotates around a single axis at high speed and can be heated, and the material is distributed to the inner wall of the mold cavity by centrifugal force, and solidified into a tubular or hollow cylindrical product by physical or chemical action (see Figure [Centrifugal Casting]).

Monomer cast nylon parts can also be molded by centrifugal casting.

In general, the higher the casting temperature, the better the fluidity of the alloy, and it is easy to obtain castings with complete shapes and clear contours. However, the higher the casting temperature, the greater the liquid shrinkage of the alloy, and it is easy to appear shrinkage porosity and shrinkage porosity. In order to ensure the quality of castings, the casting temperature should be reduced as much as possible under the premise of ensuring the fluidity of the alloy.

The so-called "high-temperature furnace, low-temperature casting" refers to the fact that after the alloy liquid is out of the furnace, it is left for a period of time, and then the casting is carried out when the temperature is reduced to a certain temperature.

The pouring temperature of carbon cast steel is generally 1610

The pouring temperature of white and gray cast iron is generally 1400

I see, but I know that the casting temperature of carbon cast steel is generally around 1610.

Stomata: the heat increases, the sand gas volume increases, the immersion stomata tends to increase; The molten steel temperature is too high, and the inhalation stomata increases; The temperature of molten steel is too high, and the precipitated pores are increased;

Shrinkage porosity: the temperature of molten steel is too high, the body expands, and the linear expansion increases, resulting in the largest shrinkage porosity of the casting;

Sticky sand: chemical sticky sand, physical sticky sand, and chemical-physical sticky sand appear seriously;

Thermal cracking and thermal cracking: In the process of solidification, thermal cracking occurs due to volume shrinkage, and warm cracking occurs due to crystal shrinkage;

Cold cracking: After the casting is solidified, cold cracking occurs due to poor cavity sintering concession.

First, the density of the casting decreases, which affects its mechanical properties. The second is to reduce the accuracy of castings and reduce the yield rate!

The pouring temperature and pouring speed determine the quality and yield of the casting, so the temperature accuracy of the pouring is particularly important. The most commonly used methods for measuring the temperature of molten iron and molten steel in the foundry industry are visual inspection and fast thermocouple insertion. In the fast thermocouple insertion method, although the temperature value can be recorded by the recorder, because the fast thermocouple can only measure the temperature at the moment of insertion, and cannot measure the temperature continuously for a long time, it can only measure a few points during the melting process, and the temperature change of the whole process cannot be grasped.

As long as it is installed at an appropriate location within 3-10 meters from the furnace mouth, the temperature in the furnace can be automatically and continuously measured, providing a reliable basis for production management and process improvement. Please contact us for specific applications.

Hello, it is a pleasure to serve you and give you the following answer: Different. The pouring temperature of cast iron in winter is higher than that in summer.

This is because the temperature in winter is lower and the fluidity of cast iron is poor, so a higher pouring temperature is required to guarantee the fluidity. The solutions to this problem are:1

Increase the pouring temperature for the first time: In winter, the pouring temperature should be increased to 10-20 times higher than in summer to ensure the fluidity of cast iron. 2.

Increase the pouring speed: In winter, the pouring speed should be increased to ensure the fluidity of the cast iron. 3.

Increase the pouring pressure: In winter, the pouring pressure should be increased to ensure the fluidity of the cast iron. 4.

Increase the viscosity of the castable: In the base season of winter leakage, the viscosity of the castable should be increased to ensure the fluidity of the cast iron. Personal Tips:

When pouring cast iron in winter, attention should be paid to increasing the pouring temperature, pouring speed, pouring pressure and viscosity of the casting liquid to ensure the fluidity of the cast iron.

It can be poured with a full mold; The lower the temperature, the better, to reduce the amount of liquid shrinkage and reduce craters and porosity. Therefore, according to these two points, the actual engineering is summarized in the general casting manual, and a pouring temperature is recommended according to the wall thickness and single weight.

The chemical composition of ductile iron except iron is usually as follows: carbon content, silicon content, total amount of manganese, phosphorus, sulfur does not exceed and appropriate amount of rare earth, magnesium and other spheroidizing elements.

The addition of rare earths is necessary due to the poor iron quality, high sulfur content (cupola smelting) and low tapping temperature in China. Magnesium is the dominant element in nodularizing agents, and rare earths can promote graphite nodularization on the one hand. On the other hand, it is also necessary to overcome the influence of sulfur and tramp elements to ensure spheroidization.

Hehe, the tone is wrong, others are not obligated to help you.

When melting ordinary cast iron, increasing the furnace temperature of the molten iron can improve the fluidity of the molten iron and improve the pouring performance. It can also refine cast iron grains and purify its structure, due to the increase of pouring temperature, it facilitates the accumulation of impurities, and reduces the segregation and slag inclusion of castings. Improve the mechanical properties of castings.

It is of great significance to the intrinsic and external quality of castings.

If the overheating temperature is too high, it will increase the shrinkage of the casting, causing shrinkage holes, cracks or coarse grains in the casting. This is especially useful for malleable cast iron and ductile iron with large shrinkage.

The impact is obvious. In this case, melting with a cupola furnace is not a big problem, it is easy to control, and it is very important when melting with an electric furnace, and it can be controlled with a thermometer if necessary.

Raising the pouring temperature of molten iron too high will also cause sintering on the surface of the casting material and a series of surface defects of the casting.

The pouring temperature is too low, and it is difficult to fill the molten iron, which is easy to cause defects such as porosity, cold isolation and insufficient pouring of the casting.

The pouring temperature should be determined according to the specific situation, and the general thin-walled castings are controlled at 1300-1340 degrees. The thick wall is controlled at 1260-1320 degrees.

In short, it is better to have a higher temperature of molten iron, adjust the pouring temperature according to the situation, master the high temperature of the furnace, and pour at the appropriate temperature, which is the best way to obtain high-quality castings.

The key to achieving low superheat casting is: (1) controlling inclusions in the steel to prevent nodules in the low superheat casting process;

2) Accurately control the temperature of molten steel in the continuous casting process;

3) Stable control of the production rhythm of steelmaking and continuous casting.

In order to control the composition of inclusions in steel, calcium treatment technology is generally used, but when the sulfur content in the steel is high, it is easy to form cas inclusions and cause nodulation at the nozzle, and the punctate inclusions formed by calcium treatment are very harmful to some steels. The use of low-alumina clean steel technology can achieve the dual purpose of improving cleanliness and optimizing inclusions. At present, the temperature of the molten steel can be controlled within a very narrow range through secondary refining, coupled with the use of tundish insulation technology and steel inclusion control technology, which creates conditions for low superheat casting.

The results show that the most effective means to control the temperature stability of the tundish is to use a plasma heating device to supplement the tundish with stable and reliable neutral heat energy. In addition, to reduce the superheat of molten steel, water-cooled nozzles or conical non-consumable condensers can be used for auxiliary cooling on the meniscus surface of molten steel.