Therelek furnaces are designed to provide high value for heat treatment applications to meet very specific requirement.
<h2>Gas / Pit Carburizing Furnace for Heat Treatment & Applications</h2> Selective Carburizing may be accomplished by masking. Unless specified otherwise, threaded ends of shafts shall be masked prior to carburizing. In through hardened parts, furnace atmosphere which increase the carbon content of surfaces above the maximum for the respective composition and increase the surface hardness above the core hardness is not acceptable. In addition, the microstructure shall not show any evidence of carburization or nitriding.
<h2>Gas / Pit Carburizing Furnace for Heat Treatment & Applications</h2> Selective Carburizing may be accomplished by maski...Read more
<h2>Surface/Case Hardening Furnace by Therelek</h2> Case hardening process is done by hardening the outer layer of steel while maintaining a soft inner metal core. This is done for the carbon addition in the steel and the hardening depth depends on the application of case hardening. Case hardening is generally carried out for carbon steel forgings, steel pinions, machine parts for manufacturing etc. Case hardening is carried out in producing horseshoes, cooking utensils and other bulk steel materials. This is carried out on the top surface and for a limited depth. Greater hardness gives better wear and fatigue resistance. The case hardening is a process where the low carbon present in the metal combining with higher carbon contents. The grouping makes the metal much harder and thus by adding low carbon metal, it can be easily molded into desired shapes. This increases the product strength and assist in iron weakening. Materials like firefighting equipment, cast iron, frying vessels require longer service time. Case hardening plays an important role in construction industry for reinforcing girders, metal panels and doors. This is performed after formation of component into its complete form.
<h2>Surface/Case Hardening Furnace by Therelek</h2> Case hardening process is done by hardening the outer layer of steel while ...Read more
<h2>Carbonitriding Furnaces for Heat Treatment by Therelek</h2> Carbonitriding is a gaseous process for the simultaneous diffusion of carbon and nitrogen into steel and consists of subjecting steel parts to the action of a carburizing gas to which is added a nitriding gas, usually anhydrous ammonia. Carbonitriding is carried out over the range 800°C to 900°C with a preference for 850°C – 900°C. The duration of treatment for a given case depth is a function largely of temperature, provided that a suitable gaseous atmosphere is employed. Furnaces used for carbonitriding are generally of the continuous type such as shaker hearth furnace, rotary drum furnace since the work is nearly always directly quenched in oil from the carbonitriding atmosphere. Batch type furnaces of the standard type used for gas carburizing may also be employed, particularly where the parts in question are not suitable for rotary drum or shaker hearth furnaces. Carbonitriding is an ideal process for the hardening of small components, where great resistance to wear is required and generally operating where the case depth does not exceed 0.025” – 0.030” <h3>Advantages of Carbonitriding</h3> <ul> <li>The process is safe, clean and simple to operate – no salts to handle no washing off, and the process can be operated by unskilled labour.</li> <li>The process is applicable to mass production methods.</li> <li>Reduced distortion due to the lower temperature required for carbonitriding as compared with carburizing, distortion is reduced.</li> <li>Improved hardenability is obtained using plain carbon steels instead of alloy steels, doe to the introduction of nitrogen into the case.</li> </ul>
<h2>Carbonitriding Furnaces for Heat Treatment by Therelek</h2> Carbonitriding is a gaseous process for the simultaneous diffus...Read more
<h2>Martempering Furnaces by Therelek</h2> Martempering is the process of interrupted quenching from austenitizing temperature in stainless steels, alloys, cast and tools. This is done to delay cooling just above the transformation for a length of time to equalize the temperature throughout the piece. Thus by reducing the cracking, distortion and residual stress. The microstructure is usually martensitic that is untampered and brittle. <strong>Martempering of steel is generally made by</strong> <ul> <li>Quench from a suitable austenitizing temperature through a liquid medium (oil, molten salt, molten metal) at a temperature above the martensite range.</li> <li>Holding in quenching medium until the temperature is substantially uniform.</li> <li>Cooling through atmospheric air at a moderate rate to prevent large differences in temperature from outside and center of the section.</li> <li>The martensite occurs uniformly throughout the work piece at the time of cooling at room temperature by avoiding formation of excessive amounts of residual stress. With the help of marquenching bath, straightening or forming is accomplished. The material retains its shape on subsequent cooling in fixture or on air cooling after removal of forming die.</li> </ul> <h3>Advantages</h3> <ul> <li>There is less thermal gradient between the center part and surface due to quenching in isothermal temperature and cooled to room temperature.</li> <li>The residual stress is lower than the conventional quenching due to thermal variations of steel in plastic austenitic condition and final transformation and thermal changes occurring on the complete part at the same time. Martempering reduces distortion, residual stress and also eliminates cracking.</li> </ul>
<h2>Martempering Furnaces by Therelek</h2> Martempering is the process of interrupted quenching from austenitizing temperature ...Read more
<h2>Hardening Furnace & Applications</h2> Hardening is the process of heat treatment in which steel is kept at a suitable temperature till it gets transformed into austenite and then quenching it rapidly. Based on the carbon content present in the steel, the temperature for austenitizing is decided. By increasing the heating time, the core gets completely transformed into austenite. The final microstructure of the hardened steel would be ferrite or martensite. Parts, where core hardening is specified, shall be tempered at a temperature not less than 280°C above the nitrocarburizing temperature. In the process of metal hardening, the mechanical properties of the components are imparted to make it fit for use.
<h2>Hardening Furnace & Applications</h2> Hardening is the process of heat treatment in which steel is kept at a suitable t...Read more
<h2>Tempering Furnaces & Applications by Therelek</h2> In the process of heat treatment, a different range of properties can be obtained by controlling the rate of cooling. Parts may be quenched in oil, water, soluble oil solutions, aqueous polymer solutions, inert or nitrocarburizing atmospheres or air. Quenching and Tempering shall be in accordance and the heating atmosphere shall be neutral to the surface of the steel being treated to prevent decarburization or carburization of the steel surface. Quenching may be direct quenched (cooled to austenitizing temperature prior to quenching) rather than being slow cooled to room temperature and hardened. Tempering shall occur within 4 hours of the quench. Soaking time shall not be less than 2 hours plus one hour additional for each inch of thickness or fraction thereof greater than 1 inch. Parts may be snap tempered for 2 hours at a temperature that is lower than the tempering temperature. This process is usually a low-temperature heat treatment which removes stress and fragile through quenching and develop the essential mechanical properties.
<h2>Tempering Furnaces & Applications by Therelek</h2> In the process of heat treatment, a different range of properties ca...Read more
<h2>Post Weld Heat Treatment Furnace by Therelek</h2> We perform Post Weld Heat Treatment to retain material strength of the part after welding. By PWHT, one can control the hardness of the material and reduce the residual stress induced. Hence, after welding, one has to process the material through Post Weld Heat Treatment. During the process engineers ensure that, the temperature do not drop below the specified degree. Apply PWHT method for the part at temperature up to 316°C. PWHT avoids Weld failures, susceptible brittle fracture and high cracking potential. <h3>Benefits of Post Weld Heat Treatment</h3> <ul> <li>Hydrogen removal</li> <li>Reduction of residual stresses</li> <li>Corrosion resistance</li> <li>Dimensional stability</li> <li>Tempering</li> <li>Enhanced ductile roughness</li> <li>Post Weld Heat Treatment is carried out in Bogie Hearth Furnace and Chamber Furnace. Most common types of Post Weld Heat Treatment are Post Heating & Stress Relieving.</li> </ul> <h3>Post Heating</h3> Hydrogen induced cracking is the common occurrence during welding. This is due to high levels of hydrogen diffuse into the material. The material after welding permeate hydrogen from the welded area. This PWHT process should start after welding and maintain a hot temperature for couple of hours. The temperature is based on the thickness and type of material used. <h3>Stress Relieving</h3> Once the welding process is complete, the material has enormous amount of residual stress. This leads to stress corrosion and hydrogen induced cracking. Hence, PWHT releases these stresses and cracking. The temperature is set to change as and when required. <h3>Factors for applying PWHT process</h3> <ul> <li>Check on previous heat treatment & alloy systems</li> <li>It may cause damage but essential for most of the materials</li> </ul>
<h2>Post Weld Heat Treatment Furnace by Therelek</h2> We perform Post Weld Heat Treatment to retain material strength of the pa...Read more
<h2>Stress Relieving Furnace Manufacturer in India</h2> This is a process involved to relieve internal stresses with no changes in microstructures. These stresses are formed within the body due to the absence of external forces. Stresses formed due to grinding, surface hammering, cold working, case hardening, electroplated coatings, castings, welding, machining, precipitation and phase transformation are treated in this process. The adverse effects with internal stress are that when steel is under residual stress under corrosive environment, it fails with stress corrosion cracking. Thus by enhancing the tendency of steel for warpage and dimensional instability. In the presence of residual tensile stress, the fatigue strength is reduced. Ductile materials are easily stress relieved when compared to brittle materials.
<h2>Stress Relieving Furnace Manufacturer in India</h2> This is a process involved to relieve internal stresses with no changes...Read more
<h2>Gas Nitriding Furnaces by Therelek Engineers</h2> The nitriding process is defined as the diffusion of nitrogen into steel and consists in subjecting parts of special steel to the action of ammonia at a temperature normally in the range 500 to 530°C. Low and higher temperatures are occasionally used. the duration of treatment is greatly in excess of that used for much deeper cases when carburizing, a normal time for nitriding being of the order of 90-96 hours. Furnaces are generally of the batch type, the temperature having to be kept correct to within ±5°C. Such close control is heat catered for by electric furnaces. Steels for nitriding comes in nitriding steels and austenitic steels. Nitriding furnaces are used in the process of nitriding metals using ammonia. Gas nitriding is a thermochemical treatment, which hardens the product.
<h2>Gas Nitriding Furnaces by Therelek Engineers</h2> The nitriding process is defined as the diffusion of nitrogen into steel ...Read more
<h2>Normalizing Heat Treatment Furnace & Applications</h2> Normalizing process is the heating of steel to a predetermined temperature for a while and then cooling it in air. This forms a microstructure with a mixture of ferrite and cementite with higher strength and hardness, but lower ductility. For improving the machinability of carbon steel, the structural components are heated to a suitable temperature and cooled in air.
<h2>Normalizing Heat Treatment Furnace & Applications</h2> Normalizing process is the heating of steel to a predetermined t...Read more