Heat treatment is a process that is loved by many industries as it can alter the physical and even the chemical properties of a material. Used primarily for compatible metals, the process of heat treatment can easily improve their wear resistance, durability, workability, strength, and magnetic properties.
There are three stages of heat treatment that workpieces undergo. The first stage is heating, which is done by exposing the workpieces to high temperatures to heat them uniformly. The heating rate of workpieces depends primarily on their heat conductivity, overall condition, and size. The next stage is soaking. This specific stage keeps the workpieces at an appropriate temperature until they acquire the needed internal properties. The soaking time depends on the workpieces’ chemical analysis and mass. The last stage is cooling, which reverts the workpieces’ temperature to room temperature.
To date, there are four types of heat treatment processes that maximise the mentioned stages.
Annealing is a type of heat treatment process that helps metals relieve stress, enhance ductility, and improve grain structures. It can also soften the metals. With annealing, metal workpieces can be processed and machined without developing internal stresses and brittle spots.
Generally, the annealing process is done by slowly heating the metals to between 400 and 1,000 Degrees Celsius (material dependent),soaking them, and cooling them by buying the workpieces in insulating material or turning off the furnace. The workpieces are often cooled gradually to below260 degrees Celsius. The time needed for soaking the workpieces depends on their type and mass.
Normalising is a type of heat treatment that removes internal stresses from various metal fabrication processes like machining, forging, welding, and casting. This type of heat treatment is often done to workpieces, particularly ferrous metals, before they undergo any hardening.
The process of normalising can be similar to annealing, especially when it comes to heating. The only difference between the two is their cooling phase. Normalising cools the workpieces through the air, which introduces changes in their microstructure. Cooling the workpieces through air likewise makes normalising a little bit faster than the annealing process.
Hardening is another type of heat treatment that aims to make workpieces harder and stronger. However, hardening can also make workpieces more brittle due to decreased ductility. To remove the brittleness of workpieces, they are recommended to undergo tempering.
Two stages of heat treatment are utilised in conducting the hardening process. These stages are heating and soaking. The third phase of hardening is different, as it rapidly cools the workpieces by plunging them into the brine, oil, wateror air cooling (usually nitrogen gas for cleanliness). Rapid cooling, which is known as quenching, is most applicable with steels.
Tempering, ultimately, is a type of heat treatment that may be similar to annealing. The finished workpieces, however, would boast different properties since they are heated in much lower temperatures. Through tempering, workpieces become easier to machine or weld. They would likewise attain workable strength, flexibility, ductility, and hardness.
Before tempering is conducted, the workpieces must undergo hardening first. Afterwards, the workpieces can be tempered by heating them to a temperature below their hardening temperature, letting them soak at the set temperature, and cooling them.
To know more about these types of heat treatment, you can call us at Alpha Detroit Heat Treatment.
Several metal parts undergo heat treatment to ensure that they boast great qualities along the way. Heat treatment is a process of heating metals below their melting stage before cooling them in a regulated way. The characteristics of metal parts vary based on the type of heat treatment that has been carried out. Some may become stronger, while others can be more ductile or malleable.
Mechanical deformations among tempered or quenched metal parts, however, can be generated whenever their stress is greater than their yield strength. And to revert their qualities to a good state, the metal parts are recommended to undergo precision straightening.
To date, two types of precision straightening can be maximised by manufacturers. These are cold and precision straightening. The following are some things that you should about them.
Cold Precision Straightening
Metal parts can be loaded into a high-power mechanical press and straightened if their microcrystalline grain has not yet assumed hardened form. They can then undergo high tolerance straightening by passing them into a grinding machine. Keep in mind, however, that cold precision straightening can only be employed on metals with high elasticity. Once hard metal parts undergo this specific type of precision straightening, they may end up having cracks and stress fractures.
Hot Precision Straightening
Hot precision straightening, on the other hand, can be maximised for parts that cannot be processed by their cold counterpart. Metal parts that undergo hot precision straightening are typically clamped. Restoration of their profile to their acceptable tolerances is then employed through controlling the direction of the linear-restoration vector. Strains may be expected after the straightening process. Therefore, metal parts are recommended to undergo further annealing.
Technological Developments
Precision straightening, in general, entails the process of passing metal parts to several rolls in varying diameters, which would differ based on the thickness of the parts. The rolls have a range of 25 to 100mm in diameter. And in choosing the best diameter, manufacturers must rely on the width of the metal parts. They likewise must pinpoint the degree of straightness they want to achieve.
As time passes, precision straightening has seen significant improvements. Manufacturers can now maximise proprietary technologies to ensure that metal parts can achieve a dead-level profile. Most of these technologies are aided by computers, making sure that all calculations will be accurate.
Without undergoing precision straightening, the heat-treated metal parts might crack or split. To know more about this specific process, you can contact us at Alpha Detroit Heat Treatment. We can offer the widest range of specialty heat treatment services for complex engineering projects and play a key role in the manufacturing of parts for all industries in Australia and New Zealand.
Metal workpieces often undergo a wide array of heat treatment processes to attain notable changes to their properties. Most of the time, these processes alter their structural and physical properties for them to be useful for subsequent manufacturing processes.
Heat treatment processes typically involve heating or chilling the workpieces to extreme temperatures. Some notable techniques that can be maximised by manufacturers during heat treatment include annealing, case hardening, tempering, carburising, precipitation strengthening, and quenching. Another process that can be utilised in altering metal workpieces is vacuum heat treatment.
The Working Principles of Vacuum Heat Treatment
Vacuum heat treatment is a method wherein metals are hardened at extremely high temperatures. It is conducted in a vacuum that possesses an absolute pressure below the normal atmosphere and does not have any air. The characteristics of the vacuum enable it to generate an unreactive environment, which can be perfect for processing metal workpieces.
Heat, after all, can provide reactions to the metal once it interacts with the air. Without the vacuum chamber, the metal workpieces may develop surfaces that are harder or softer than the expected outcome. The oxidation process, therefore, is prevented with vacuum heat treatment.
When conducting vacuum heat treatment, the vacuum chamber maximises a vacuum pumping system that can remove the air. Once the air is removed, the metal workpiece inside the chamber is then heated up to 1,316 degrees Celsius at a controlled rate before lowering the temperature. The soak time of this process typically depends on the requirements of the part and its material.
Vacuum Heat Treatment’s Noteworthy Advantages
There are a couple of advantages that one can obtain from vacuum heat treatment.
One of the advantages of vacuum heat treatment is that it eliminates the need for oxidation and decarbonisation. Oxidation and decarburisation can easily affect the quality of the workpieces negatively. But since the air is removed from the vacuum chamber, the metal workpieces can effectively retain their lustre and mechanical properties despite undergoing heat treatment.
Another advantage of vacuum heat treatment is it eradicates additional cleaning processes. Metal workpieces that undergo vacuum heat treatment do not have to be cleaned just to make their surface aesthetically appealing. This benefit helps manufacturers conserve time and money.
The mechanical properties of the metal workpieces are likewise preserved with vacuum heat treatment. Aside from removing the air, vacuum heat treatment can also help decrease hydrogen levels inside the chamber, preventing the workpieces from getting brittle. Once the heat treatment process is done, the metal workpieces are expected to gain ductility, fatigue, and toughness benefits. They can even attain improved lifespan and enhanced functionality.
Principal Applications of Vacuum Heat Treatment
Vacuum heat treatment can be very effective in processing workpieces made from metal-based super alloys like iron-nickel or cobalt-nickel. It can likewise be utilised in processing reactive and refractory materials such as titanium and stainless steel.
Some industries that can take advantage of this process is aerospace, aircraft, and automotive.
To learn more about vacuum heat treatment, you can call us at Alpha Detroit Heat Treatment.
Manufacturers can maximise a wide array of heat treatment processes to ensure that their parts and products can boast improvements over their general characteristics and properties. One heat treatment process that manufacturers often utilise is annealing.
Annealing is a heat treatment process that is well-known for soft metals. The primary purpose of the annealing process is to increase the ductility of the metals. It can likewise ensure that the metals can be formed and shaped more effectively and efficiently. Soft metals tend to lose their ductility as they undergo work hardening, especially when they are exposed to bending, cold forming, or drawing processes. With annealing, the original properties of the materials can be obtained again.
To date, the annealing process can be done through three primary stages. These stages are recovery, recrystallisation, and gain growth.
Recovery Stage
The recovery stage of annealing recovers the physical properties of the metals. Some metal properties that are expected to be recovered during this stage are electrical conductivity, internal energy, and thermal expansion. During this stage, the furnace or other heating devices is maximised to increase the temperature of the materials, softening the metals and relieving their internal stresses.
Recrystallisation Stage
The recrystallisation stage, on the other hand, is a restorative process wherein the materials are heated above their recrystallisation temperature but below their melting point. During this particular stage, any deformed grains of the metal’s crystal structures are substituted with new stress-free grains, which came from the recovery stage. Once the stress-free cells nucleate and grow, the materials would possess new grains without residual stresses.
Not all materials, however, must be heated into a critical temperature range to undergo this stage. Mild steel products, for instance, can already be softened at 500 to 650°C.
Gain Growth Stage
One more stage of annealing that the materials often undergo is the gain growth stage. The grain growth stage is carried out whenever the annealing process continues with the involved materials. Once the recrystallisation has been done, the gain growth stage follows, making the microstructure of the metals coarse as they are cooled. During this stage, the materials may lose some of their strength. However, the lost strength can be regained through hardening processes like quenching and tempering.
Even though they tend to consume a lot of time, the annealing process and its accompanying stages are essential since they can make the materials workable. Without this particular process, the materials may crack and incur other damages that would only affect industrial operations.
To know more about the annealing process and its stages, you can call us at Alpha Detroit Heat Treatment. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements. We pride ourselves on providing quality service and reliability.
Heat treatment is the process of heating metal workpieces without reaching their molten or melting stage. After heating them, they are cooled in a controlled way so they can obtain the needed mechanical properties. Some heat-treated workpieces may become more malleable, while others can become stronger. Metal workpieces can also become more ductile or resistant to elements.
There are a lot of heat treatment techniques that can be conducted by manufacturers to ensure that they obtain their needed products. Some of these techniques are annealing, precipitation strengthening, case hardening, carburising, quenching, tempering, and normalising.
Another heat treatment technique that is being conducted by manufacturers today is nitriding. Nitriding is a heat treatment technique that can generate case-hardened products by applying nitrogen.
The Processes of Nitriding
As mentioned earlier, nitriding is a heat treatment process that can generate products with case-hardened surfaces. Through the infusion of nitrogen, products are expected to obtain increased surface hardness. But before carrying out the nitriding process, the workpieces should be hardened, quenched, and tempered first to ensure they possess a uniform structure. The workpieces must also be free from any oils, grits, and others through abrasive cleaning or vapour degreasing.
The whole process of nitriding depends on its type.
Main Benefits of Nitriding
No matter what type of nitriding one has to carry out, all nitriding processes are expected to provide excellent advantages on products.
One of the advantages of nitriding processes is that they can process workpieces very quickly. They likewise do not require a lot of energy to carry out and finish the operations. Nitriding processes do not also need extremely high temperatures to generate reliable products. They do noteven generate pollution and emit toxic wastes to the environment.
As for the products, they are expected to gain significant improvements over their fatigue properties, surface, and hardness. Products that undergo nitriding processes can boast a uniform surface, a high surface hardness, and a minimised distortion. They also have improved corrosion resistance.
To know more about nitriding, you can call us at Alpha Detroit Heat Treatment.