Prevention and elimination of forging cracks (2)

Ultrasonic testing showed that the existence of cracks and pore defect of large forgings is an important cause of waste, most of which is due to internal blank there are loose, coarse grained inclusions, and cracks. They are due to the local inhomogeneous deformation, under great stress concentration and shear stress, which leads to the closure, compaction and the generation of deformation damage. Therefore, smelting of refractory raw materials, hot forging comprehensive control, cracks and eliminate the cause and condition is the effective measures to improve forging quality. However, for large forgings with inner crack defects have the healing repair, reopening to prevent scrap also has important economic significance.

The principleof crack repair: any structure and composition of heterogeneous refractory materials (including micro cracks), in the permit conditions, will tend to homogenization. Its essence is in force (diffusion concentration, electric field, stress field gradient) under the effect of diffusion and migration of metal atoms, the orientation of inner crack healing.

Now the application of high temperature diffusion treatment, pressure diffusion, diffusion and plastic deformation of the combination of healing methods. It have get obvious effect in the large tube plate, large module inclusion crack repair achieved remarkable results, and in the rolling steel tube, crack control.
The crack initiation and propagation in the forging process can be prevented and eliminated by using the internal crack repair mechanism effectively by means of the study and test method of hot forging crack, and combined with the microstructure and thermodynamic analysis of the forging cracks.
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. what's more ,you can know more kinds of refractory information from our website.
Article Source:Prevention and elimination of forging cracks (2)
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

The classification of complicated shape brick

Chinafirebrick provides refractory products, calcium silicate products, castable & mortar, fire brick china, ladle & tundish nozzle, ceramic fiber with high quality for you. Refractory brick manufacturers suggest that special-shaped refractory bricks according to the preparation process can be divided into firing bricks, not burning bricks, fused brick (cast brick), fire-resistant insulation bricks; specific type of refractory bricks by shape and size can be divided into standard Brick, ordinary brick, and so on. Shaped refractory bricks can be used as high-temperature building materials and structural materials for building furnaces and various thermal equipment. Shaped refractory bricks can withstand various physical and chemical changes and mechanical effects at high temperatures. Such as refractory clay brick, high alumina brick, silica brick, magnesia carbon bricks and so on.

Special strength refractories bricks, its main feature is the early high strength, 3-7 days maximum room temperature compressive strength of up to 30MPa or more, the disadvantage is poor in the temperature volumetric stability, reduced strength, the maximum decline of up to 40%, so require room temperature Strength must meet the design and national standards requirements. The main factors that reduce the temperature strength are: low-calcium high-alumina cement of special-shaped refractory brick in the heating furnace oven heating process to a certain temperature (350 ℃ or so), the hydrate began to dehydrate, the hydration of cement stone structure, dense Degree and strength decreased, castable volume changes, then castable body strength dropped to the lowest point, then stabilized.

With the heating temperature rose to 1100 ℃, the cement stone gradually sintered, shaped refractory brick crystal began to convert mullite crystals. With the rising temperature, mullite crystals continue to grow, castable in the matrix glass phase was liquid state, the formation of high temperature ceramic sintered, the strength significantly improved. At about 1300 ℃, the strength of the special-shaped refractory brick body can reach more than 60MPa, which is a special characteristic of the special-shaped refractory bricks at high temperature.

Xinmi Changxing furnace refractory Tips: You may also on the refractory fire brick, magnesia carbon brick, refractory manufacturers, refractory bricks prices, high alumina refractory bricks, clay refractory bricks, Henan refractory brick factory, Xinwei refractory brick factory, Xinwei refractory brick factory Interested if you have any need please call our service hotline.

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. what's more ,you can know more kinds of refractory information from our website.

Article Source: Thermal conductivity of refractory bricks
Company name: Henan Xinmi Changxing Refractory Materials Co.,Ltd
Email: sales1@chinafirebrick.com
Website:http://www.chinafirebrick.com/

what are the details of Ladle Nozzle Well Block?

Ladle Nozzle Well Block

Introduction:

The ladle nozzle well block connects the wearing refractory lining of the ladle bottom to the mechanism or ladle gate for the flow control. To the well block is asked a huge wearing resistance and moreover it has to protect the nozzle placed inside it. Our ladle nozzle well block is made with magnesia carbon material or alumina carbon material, which can be made according to customized.

The ladle nozzle well block can be realized in any size and shape and strengthened with steel fibers to improve its mechanical resistance.

The series of well blocks for nozzles are made from high-purity, high-density, high-strength materials. Based on different materials, they have corundum, magnesia carbon and alumina spinel carbon. 

Advantages:

They show the features of stable structure, excellent thermal shock resistance, good corrosion/erosion resistance and long service life.

Application:

It is mainly used to fix upper nozzle in steelmaking.

Specific Application:Used to fix upper nozzle.


Service Life:Make plain carbon steel, 100 heats MIN; for refining ladle, 30 heats MIN.

Article source:  Ladle Nozzle Well Blocks