Heat treatment is a process wherein metals are heated without reaching their molten phase and subsequently cooled to obtain the desired properties. Different types of ferrous and non-ferrous metals can undergo this process, maximising a wide array of heat treatment methods to produce the needed parts and products of various businesses and industries.
Many businesses have benefitted from heat treatment as the process and its associated methods can generally change the properties of metals. Some of them can increase the hardness of the metal, while others can make it soft. There are likewise heat treatment methods that can relieve stresses of the metal as well as alter their electrical and heat conductivity, making them useful for specific applications.
One vital part of heat treatment is stress relieving. It is done to diminish residual stresses in the metal structure, saving it from dimensional changes that may occur during its manufacturing or intended use.
A Quick Overview of Stress Relieving
Stress relieving, as the name implies, serves as the main way of saving metal workpieces from different effects of stress, which can be obtained from various heat treatment procedures. As a workpiece undergoes different heat treatment procedures, it can obtain different effects that are not truly great. Some of these effects are shape distortion, fractures, cracks, and many more. With stress relieving, these effects, alongside any dimensional changes to metal workpieces, are minimised.
This part of heat treatment is often done after rough machining. It must also be conducted before final finishing like polishing or grinding to ensure that the workpiece can still boast its desired properties.
Stress Relieving Working Principles
The temperature for the stress relieving part would normally range between 550 and 650°C for steel workpieces, 150 and 275°C for copper parts, and 250 and 500°C for brass products, with an average soaking time of around one to two hours. Once the soaking process is done, the workpieces will be consequently cooled down either in the furnace or in the air. The cooling process must be slow and gradual to prevent any instances of tensions that may be generated due to the differences in temperature between the workpieces and the surrounding.
Some metal types, however, might need to be placed in a furnace with protective gas during the stress relieving process to ensure that they will be protected from oxidation. Vacuum furnaces can also be used.
Common Benefits of Stress Relieving
The working principles of stress relieving can provide tons of benefits to various workpieces. For one, this specific process can minimise the stresses that a workpiece can obtain from other heat treatment methods, which would then lower its chances of obtaining cracks and deformation. Stress relieving can likewise allow a workpiece to be machined easier after undergoing heat treatment. The process can also protect the workpiece from volatile surrounding elements, protecting its surface and other properties.
To know more about stress relieving, just reach us at Alpha Detroit Heat Treatment. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.
Metal materials are typically processed out of various heat treatment methods. Heat treatment, in general, is the process of heating and cooling metal materials to effectively develop and achieve certain physical and mechanical properties. And through the heat treatment process, metal materials can expect significant changes to their softness or hardness. The electrical and heat conductivity of these materials are also altered once they are subjected to different heat treatment methods.
One heat treatment method that is often utilised in processing metal materials is tempering. Tempering is a heat treatment method wherein a metal material after hardening from a high temperature is then subsequently re-heated to a lower temperature than the hardening temperature and cooled slowly. Tempering is normally done to reduce hardness and brittleness and internal stresses, with increased toughness achieved.
A General Overview of Tempering Process
As previously stated, tempering can reduce the brittleness and internal stresses of a metal material. The reduction of these elements allows the material to gain improved toughness and strength, allowing it to hold up and sustain the effects of other processes. The temperature for heating during tempering is typically below the hardening temperature of the material, which often ranges from 160 – 650 deg C.
The tempering process is conducted by heating the material to the mentioned temperatures and upholding the heating process for a certain amount of time. The values of both the heating temperature and the time needed for the heating are determined by the type of metal that is being processed. After the heating process, the metal material will be cooled. The cooling rate is likewise determined by the type of metal processed, impacting all the changes in the material’s overall mechanical properties.
Comparing Tempering to Other Methods
There are other heat treatment methods that can be done to introduce changes to metal materials. Some of these methods are annealing and hardening.
Annealing is a heat treatment method wherein a metal is heated and subsequently held to an ideal temperature at a predetermined time. The cooling will then be initiated gradually. With annealing, the metal material is expected to obtain an increase in ductility and a significant decrease in hardness, making it more workable for other processes.
Hardening, alternatively, is a heat treatment method that has the purpose of increasing the hardness of a metal material. This method is done by heating the metal material to a very high temperature for it to effectively disperse solute-rich precipitates. To avoid any reprecipitation, the metal material is then cooled at a rate which is material dependent, which is done by quenching it in inert gas, air, oil or water.
What makes tempering different from others is that it entails the reheating of metal materials to a temperature lower than hardening temperature, holding it for a certain time, and cooling it. Tempering likewise reduces the brittleness of the material, making it much easier to process. This specific process can also work on steels, while both annealing and hardening can be used for metals and metal alloys.
Tempering at Alpha Detroit Heat Treatment
If you need tempering services, feel free to call us at Alpha Detroit Heat Treatment. We provide a wide range of services for all your heat treatment needs. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.
Different heat treatment processes are being conducted when working with steels and other types of metals due to numerous reasons. One of the key reasons why these materials undergo the said processes is to improve their overall strength and hardness. These processes can also provide them resistance to elements, particularly corrosion. The physical properties of the materials as well as their ductility are likewise altered by heat treatment processes.
Overview of Salt Bath Heat Treatment
One particular process that can provide numerous additional features to different types of steels is known as the salt bath heat treatment. This specific process is often conducted in a furnace that has a ceramic or metal container and is filled with molten salt. The salt bath heat treatment utilises one or more types of salts, nitrates, chlorides, carbonates, cyanides, caustics, and small amounts of other additives.
An involved workpiece is often immersed for the heating process, with the heat being transferred between the said material and molten salt through conduction. The cooling process can also be done with salt bath heat treatment thanks to the excellent conductivity of molten salt.
Heat is generated by the furnace through its resistance to current passage, with heavy electrode bars causing salt circulation once the electromagnetic forces are energised. A strong magnetic field is then created between electrodes, causing salt particles to move downward. The movement of these particles can ensure that the bath will obtain absolute temperature uniformity throughout the heat treatment.
Salt Bath Heat Treatment Features
One great feature of salt bath heat treatment is that it can work on and cater to different types of steels. This treatment can process low, medium, and high-carbon steels. Even ceramics and plastics can be processed with salt bath heat treatment.
Another great feature of salt bath heat treatment is that it can effectively provide quick heating of a workpiece. As the workpiece is immersed into the furnace, it is effectively heated through conduction by maximising the liquid media. With liquid media, the heat transfer rate is deemed faster than other heating mechanisms like radiation and convection by gas. Immersing the workpiece in a salt bath can likewise protect the workpiece from the effects of the atmosphere.
As mentioned before, salt bath heat treatment can also be great in terms of cooling. The cooling process in the molten salt is known to be slower compared to conducting it in other quenching media. The former can even stop at a much lower temperature. Conventional quenching processes, alternatively, often have a high cooling rate, which could only cause cracks and distortions on the workpiece.
Salt Bath Heating at Alpha Detroit
Salt bath heat treatment can effectively conduct numerous processes such as quenching, hardening, nitriding, carbonitriding, carburising, solution treatment, and deep brazing. If you want to know more about high-temperature salt baths, feel free to contact us at Alpha Detroit. We provide a wide range of services for all your heat treatment needs. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.
Heat treatment is a process of heating or chilling a specific material, usually a metal, at a certain temperature. This process enables the metal to undergo significant changes when it comes to its mechanical properties and overall microstructure.
There are several types of heat treatment techniques that can be done with metals. Some of these are annealing, case hardening, precipitation strengthening, tempering, and quenching. While these techniques can provide beneficial changes to metals, some of them would only generate mechanical deformations and distortion zones that can be resolved or removed by a particular technique.
An Overview of Precision Straightening
Precision straightening is a technique wherein a particular metal material undergoes simple straightening and fine levelling for it to acquire a precise level of straightened features and characteristics. This particular technique or process is normally done by subjecting sheets of metal to numerous rolls in varying diameters. The diameters differ according to the desired thickness as well as the width and the degree of straightness of the metal material.
This specific technique can be similar to both conventional normal straightening and fine levelling processes due to the number of counter-rolls that are present on the machines used for the process. The rolls can range from 25 to 100mm in diameter, enabling them to process different types and specifications of metals. Thinner materials require more rolls compared to the thicker ones.
Cold and Hot Precision Straightening
Metal materials that have not yet obtained an overly hardened form can still be subjected to a powerful mechanical press and a grinding machine. Although, one element that must be considered before choosing between cold and hot precision straightening is the plasticity quotient of the metal’s structure. Metal parts or sheets that have a low elasticity limit may lock them on their twisted form.
Cold precision straightening can generate parts that are harder, stiffer, and stronger. It can, however, cause cracks and stress fractures, making the parts or sheets unusable. Hot precision straightening, alternatively, can be effective in a lot of metal materials since their profiles can be restored to their acceptable tolerances without expecting any of the effects of cold precision straightening.
Modern precision straightening techniques, fortunately, are now maximising technologies that could effectively spot and resolve flaws in metal materials.
Alpha Detroit Heat Treatment Services
If you need help with precision straightening, feel free to contact us at Alpha Detroit Heat Treatment. We have a range of straightening presses up to 20-tonne capacity. We can likewise work on both cold and hot precision straightening to effectively cater to your needs. We can also remove twists that may be present on the metal materials through our specially adapted de-twisting press.
We pride ourselves on providing quality service and reliability, as well as a wide range of services for all your heat treatment needs. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.
Non-ferrous metals are metals that are not comprised of iron content, which gives them significant resistance to corrosion and rust that can be very useful for outdoor applications. They are also non-magnetic, allowing them to be used for electronic applications.
One metal that is part of the non-ferrous metal family is aluminium. It is lightweight, soft, and can be processed easily. This metal, however, has low strength. Therefore, different methods of heat treatment are carried out to alter their strength. Heat treatments also allow aluminium to be machined or welded easily, change their mechanical properties, obtain wear-resistant properties, improve brittleness, and enhance compatibility with other types of materials.
To date, there are numerous types of aluminium heat treatments that you can maximise. Some of these types are as follows:
Annealing
The plastic deformation of aluminium that is subjected to strain hardening allows its grain structures to slide against each other along slip planes. As the instances of plastic deformation continue, the number of slip planes decreases, requiring the aluminium to have more force to obtain further deformation. To reset the crystalline grain structure, restore the slip planes, and relieve the internal stress of an aluminium alloy, it must undergo the process of annealing. Annealing is conducted by heating the aluminium alloy between 298°C to 410°C for around thirty minutes to three hours. An aluminium alloy that is subjected to annealing can be worked more easily compared to one that has not been processed.
Solution Heat Treatment
Solution heat treatment, alternatively, is a process wherein the age-hardening elements are dissolved. During this process, a part must be rapidly cooled after heating to effectively distribute the dissolved elements in the alloy. The temperature needed by an aluminium alloy for the heating process ranges between 440°C and 526°C. The temperature must be, nevertheless, within ±12°C of the target temperature so that the solution heat treatment can yield great results. The soaking time of the heated part, subsequently, may range between 10 minutes and 12 hours, depending on its size and dimensions. Ultimately, it must be quenched to trap elements in place and avoid them from precipitating.
Precipitation Hardening
Precipitation hardening, also known as artificial aging, is another type of heat treatment that allows an aluminium alloy to reach its maximum hardness. This heat treatment process is conducted by heating an aluminium alloy between 115°C and 274°C, within ±15°C of the intended temperature. The alloy must be consequently soaked for around 6 to 24 hours and then cooled to room temperature. Once the precipitation hardening is finished, the aluminium alloy is expected to obtain a significant increase in yield strength, a slight increase in tensile strength, and a decrease in ductility. An aluminium alloy that cannot reach its peak hardness during natural aging at room temperature can utilise precipitation hardening.
To obtain high-quality aluminium heat treatment processes, feel free to contact us at Alpha Detroit Heat Treatment. We provide a wide range of services for all your heat treatment needs. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.