Processes in Önerler
​For carburizing and carbonitriding processes, atmosphere controlled shuttle kilns are used in our company. In the heating chamber, carbon and nitrogen in the ambient atmosphere are enriched to provide diffusion to the steel surface.​
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We offer flexible charging opportunities to our customers with various furnaces with charging capacities of 600 - 1000 - 2000 kg.
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The origin of all of our 5 furnaces is Germany, and their brand is IPSEN, which is the world pioneer in its field.
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The Carb-o Prof program in our furnaces makes it possible to control parameters critical for the process - such as gas flow, temperature, protective atmosphere composition, oil temperature, cooling rate, etc. - and thus providing high reproducibility and traceability.
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Thanks to the Rapid-quench system, the materials cool faster and reach the possible maximum hardness value.​
Since 1967, when our company was founded, we offer our customers the best quality with our state-of-the-art equipment and experience in carburizing process which we have been carrying out for 50 years.
Carburizing Process
Carburizing is a thermochemical Process performed between 800 and 950 degrees. During carburizing, the steel is heated and its temperature is raised above the austenitic point, and in the environment of the process, a carbon-rich protective atmosphere is created to provide carbon diffusion from the steel's surface to its core. The steel whose surface is carbon-enriched, then is submerged in oil and cooled rapidly. Quenching (rapid cooling) can be done directly or with different intermediate steps to reduce waste. Following these processes, martensitic transformation is achieved in the material, starting from the steel's surface to a certain depth. When the areas in which this transformation occurs are hardened, the core section is soft or has a lower hardness than the surface depending on the type of steel. In this process, the steel is hardened to to a depth of 0.05 - 2 mm according to usage features.
After carburizing, the steel is tempered to reduce the stresses in the material, and the required final hardness value is obtained.
Carbonitriding Process
Carbonitriding process is a modified version of the carburizing process. In addition to carburizing, ammonia is added to the furnace atmosphere; by this way, nitrogen is added to the steel surface along with carbon. The difference between the process and carburizing is that it is performed at lower temperatures, in shorter process times, and as a result, a thinner hardness layer is formed. Carbonitriding is usually carried out in cases where a depth of roughness of 0.05-0.5 mm is required, and steels unsuitable for carburizing are selected.
By tempering the steel after carburizing, the stresses in the material are reduced and the required hardness value is obtained.
Benefits of Processes
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High rupture strength
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High wear resistance
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High surface hardness
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High toughness
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High fatigue strength
Low carbon steels are both easy to process and cost less than other steels. According to their area of use, the required mechanical properties (hardness, strength, etc.) and wear resistance for these types of steels are provided by carburizing and carbonitriding processes. After carburizing and carbonitriding, high wear resistance and high toughness values are obtained with a hard surface and relatively low core hardness.
Another feature of the carburizing and carbonitriding processes is partial hardening of the part. Only the desired areas can be hardened by preventing carbon or nitrogen diffusion through the application of special paste to the surface.
Suitable Steels
Carburizing is generally applied to steels containing 0.2% or less carbon. In the following table, steels used intensively in the market and subjected to carburizing process, and maximum hardness values they can gain after the carburizing process are given in Rockwell.
Potential Risks After Processes
One of the most troublesome problems in the carburizing process is the dimension change in the materials, namely waste. Carburizing is a thermal process. The material is cooled rapidly after being heated at high temperatures, in this case the material naturally first expands and then shrinks rapidly, and when the material reaches the maximum possible hardness, stresses in the material also increase excessively. Even if the material is heated homogeneously, as a result of the shape of the material (especially thin and thick sections) and the processes carried out before heat treatment, inhomogeneous stresses in the material can cause increased waste and even the material to crack.
After martensitic transformation in carburizing, hardness is at the maximum level and internal stresses are at the highest level. If a steel in this state also contains residual stresses due to the processes prior to heat treatment, there may be more waste, or cracks may occur.
If a steel with high internal stresses is required to be tempered, in this case, the internal stresses of the steel should be removed by stress relief annealing.
Heat Treatment
BOSB Turuncu Cad. No: 12, 16120
Nilüfer/Bursa, TURKEY
+90 (0224) 242 43 10
+90 (0224) 242 43 11 (fax)
Steel Supply
BeÅŸevler Sanayi Sitesi 26.Blok No: 6-15
Nilüfer/Bursa, TURKEY
+90 (0224) 441 97 13
+90 (0224) 441 46 15 (fax)