Metals and alloys undergo various heat treatment processes to obtain changes in terms of their general properties and microstructures. Most of the time, these processes can strengthen the structure of the mentioned materials by heating and cooling activities. They can likewise relieve stresses, increase surface hardness, amplify strength, and make them easier to machine or weld.

A wide array of heat treatment processes can now be utilised in altering the properties of metals and alloys. Some of these processes include annealing, case hardening, precipitation strengthening, quenching, and tempering. Another process that can be done to specific types of metals is carbonitriding.

An Overview of Carbonitriding

Before knowing what carbonitriding is, you should understand two concepts first. One of these concepts is the case hardening process. The case hardening process is a process of granting metals additional thin layer of harder metal on their surfaces while retaining their softness underneath. Another concept that you should know about is carburising. Carburising is a thermochemical process wherein low carbon steels are diffused with carbon, yielding a durable surface layer.

And with these two concepts, carbonitriding can now be easily understood. Carbonitriding is a case hardening process that closely resembles the carburising technique. Just like carburising, carbonitriding also integrates carbon into metals for them to have durable surfaces. Nitrogen, however, is also added during the carbonitriding process, further increasing the wear resistance and surface hardness of metals being processed. A hardened surface layer is expected out of this process.

Carbonitriding Main Processes

When conducting the carbonitriding process, metal workpieces are often heated in a sealed chamber before adding the nitrogen and carbon elements. The temperature of the heating process typically ranges between 820 to 900°C. During the heating, the workpieces are expected to generate some phase changes on their crystal structure, allowing carbon and nitrogen elements to diffuse into them easily.

The amount of carbon that is added to the workpieces typically ranges between 0.5 to 0.8%, while the amount of nitrogen added to the same workpieces would range between 0.2 to 0.4%. Most metal workpieces that undergo carbonitriding are plain carbon steel or low alloy steel since they do not harden well with other heat treatment processes.

To ensure metal workpieces will obtain high surface hardness and ductile core, the entire carbonitriding process should take from a few hours up to a day. Once the diffusion process is completed, the workpieces are then directly quenched in oil.

Key Benefits and Applications

As previously stated, the carbonitriding process helps metals attain a strong, durable, and wear-resistant case. Distortion and quench cracking among metal workpieces are likewise reduced as carbonitriding only requires lower temperature and slower quenching speed compared to other processes. Aside from obtaining this type of case, this process can also benefit industries since it can cater to a cleaner mass production of small metal components.

All these benefits of carbonitriding make them great for producing small components such as gears, shafts, rollers, bearings, pistons, and levers in various systems.

To know more about carbonitriding, you can call us at Alpha Detroit Heat Treatment.

The general properties of metal materials allow them to undergo numerous processes. These processes can help modify and even improve their core properties so that they can be useful for a lot of industries.

One of the processes that can be done on metals is carburization. Carburization is a process that hardens the exterior of metals by diffusing carbon atoms into their surface and other workable layers. Metals that undergo carburization often have low tensile strength and hardness, preventing them from withstanding wear and tear after prolonged use. Through carburization, their strength and hardness are expected to improve given the integration of carbon to the metals.

An Overview of Carburization

Carburization, as previously stated, entails the hardening of metal workpieces through diffusing carbon atoms into their surface and other possible layers of the materials. Before the process is conducted, the surface and other parts that will be diffused with atoms will be cleaned first to remove any contaminants. During the process, the metal workpiece is heated in an environment filled with carbon-rich solids, liquids, or gases. Over time, these carbon sources will decompose, allowing the carbon atoms to be liberated and subsequently diffused into the metal workpiece.

The duration of the process typically depends on the temperature of the heating. It is also affected by the carbon potential of the workpiece. Ferrous metals can fully maximise the effects of carburization, particularly those that are comprised of low carbon.

Aside from obtaining better strength and hardness, carburization allows metal workpieces to attain better corrosion resistance, improved fatigue strength and mechanical strength, remarkable toughness, respectable wear resistance, and relieved internal stresses.

Positive and Negative Impacts

The process of carburization, as expected, can bring tons of positive impacts to the processed metal workpieces. As stated earlier, the process allows metal materials to develop hardened layers, improving their mechanical strength, fatigue strength, toughness, wear resistance, durability, corrosion resistance, ductility, and surface hardness. With the improvements over these qualities, metal workpieces that undergo carburization are projected to last for a long time.

The depth of the hardened layers or cases may be altered based on the applications of the metal materials. Metal workpieces that must be replaced all the time may have a shallow hardened case, while those that must sustain shock loads or crushing loads may benefit from higher case depths.

But just like other processes, carburization may also have some negative impacts or limitations. For metal workpieces that are asymmetrical, the application of carburization to these materials may lead to stress build-up and cracking due to the cooling rate differential. These things may also happen if the process is done with nonuniform materials. Aside from these effects, carburization can also yield expensive machining costs due to the consistent changes in dimensions, shapes, and distortions during the process.

To know more about carburization, feel free to give us a call at Alpha Detroit Heat Treatment.

Metal workpieces generally undergo different machining and fabrication processes so that they can generate different types of products. Once these products are produced, manufacturers would often subject them to a wide array of surface finishing processes to effectively enhance their appearance, strength, and other significant qualities.

Surface finishing, as previously stated, can alter and improve the appearance, strength, and other properties of finished metal products. It can be done by different processes. Some of them can be conducted mechanically, while others are done through either chemical or electrical means.

One surface finishing that is done by chemical means is black oxide coating. It is typically conducted on products made from ferrous metals, allowing them to obtain significant property improvements.

The Process of Black Oxide Coating

The black oxide coating is a surface finishing process that introduces a protective barrier to ferrous products. This specific process is typically done by dipping the mentioned products into an alkaline salt solution, allowing the surface of these products to chemically react to the solution. The solution that is being utilised by this process can vary depending on the properties of the metal products. It may be applied at room temperature. It may also be done in either cold or hot processing methods. Some applications might likewise require components to be pre-treated. 

Once the metal products interact with the solution, magnetite is generated on their surfaces, creating a protective barrier that will keep them safe from moisture and other damaging elements. The black colour of the magnetite is the main reason behind the name of this surface finishing process.

Different applications can maximise the process of the black oxide coating. For one, this process can be used on small moving parts such as gears, tools, and machine components. Black oxide coating can likewise be utilised in military applications, surgical instruments, and architectural assemblies.

Advantages of Black Oxide Coating

What makes black oxide coating great for some applications is that it can protect metal products from corrosion. Due to the development of magnetite on the surface of the products, it can easily protect them from moisture and elements that can generate corrosion. The process can even prevent hydrogen from infiltrating and damaging the products. It can likewise avoid the production of white corrosion.

Another advantage of black oxide coating is that does not add significant thickness to the dimensions of metal products. Since the process is done chemically, minimal dimensional changes can be expected to the processed products. This advantage alone makes the process great for small and intricate products.

Ultimately, black oxide coating can be beneficial for some applications as it can boost the appearance of metal products. The protective coating of the magnetite prevents the products from peeling, flaking, chipping, or rubbing off, preserving their appearance effectively. The dark black colour coating likewise makes the metal products appealing for some applications. This colour can even minimise eye fatigue and light glare that can distract a lot of people.

To find out more about black oxide coating, just contact us at Alpha Detroit Heat Treatment.

Raw ferrous and non-ferrous metal materials must be handled and processed properly to ensure that they can be utilised in a wide array of applications. And to achieve this, manufacturers must apply and conduct specific heat treatment methods so that these materials can sustain remarkable properties.

The continuous improvements over the heat treatment methods have allowed metallurgists to come up with metal materials that are cost-efficient and long-lasting. When conducted properly, these metal materials can certainly attain physical and chemical properties that can make them useful in the long run. Heat treatment methods can specifically relieve stress, making the metal materials easier to process. They can also generate metal materials that are sturdy, strong, flexible, and wear resistant.

Basic Properties of Non-Ferrous Metals

One type of metal materials that can be processed by manufacturers is non-ferrous metal. Non-ferrous metals are metals or alloys that do not contain iron in huge amounts, making them softer and more malleable. Other properties that non-ferrous metals contain include high corrosion resistance, low density, and excellent thermal and electrical conductivity. They are also easy to fabricate and non-magnetic. All these properties allow these metals to be useful in a lot of applications.

A lot of popular metals and alloys are part of the non-ferrous classification. One of these is copper. Copper, with the integration of alloys brass and bronze, has been useful in generating mechanical components and devices that are intended for industrial applications. Another non-ferrous metal that is popular nowadays is aluminium due to its lightweight, high ductility, and corrosion resistant. This type of metal has been very useful in creating automotive parts, consumer electronics, and household components. Lead and zinc are likewise part of the non-ferrous metal category.

Heat Treatment of Non-Ferrous Metals

Numerous heat treatment methods can be conducted on non-ferrous metals. Two of these methods are solution heat treating and annealing.

Solution heat treatment is the heating of non-ferrous metal or alloy to an appropriate temperature, holding it for a specific time until one or more of its elements enter into a solid solution. Subsequently, the whole non-ferrous metal or alloy is cooled rapidly or quenched so that the elements will be held effectively. To ensure that the metal or alloy will not revert to its original configuration, aging and precipitation hardening will be consequently conducted. These steps help the non-ferrous metal attain greater tensile strength.

Annealing, alternatively, is conducted to boost the ductility of the non-ferrous metal or alloy and, at the same time, reduce its overall hardness. This process can be conducted in metals or alloys that are still heat-treatable. During the annealing process, the metal or alloy is subjected to heat at a certain temperature. Subsequently, the metal or alloy will be cooled slowly to room temperature. The slow cooling process of annealing allows the metal or alloy to generate a refined microstructure.

To know more about these heat treatment methods, feel free to reach us at Alpha Detroit Heat Treatment.

There are a lot of products today that are comprised of metal parts and components. And with a wide array of metal materials that can be processed to generate these parts and components, their existence in different industries truly makes them valuable for various applications.

One of the metal materials that are often used for producing parts and components is stainless steel. Generally, stainless steel has excellent resistance to corrosion and temperature. It also boasts high tensile strength, respectable durability, and ease of formability and maintenance. It even has an attractive appearance that makes it perfect for applications that prioritise looks and aesthetics. Stainless steel, ultimately, can be recycled. Most of these qualities are present in different types of stainless steel.

All About Martensitic Stainless Steels

Stainless steels can be grouped based on their crystalline structure. And one of the groups of stainless steel that is common today is martensitic stainless steel. Martensitic stainless steel is a specific type of stainless steel that is known for its durability, strength, and corrosionresistance. These qualities are present in this type of stainless steel since it is composed of chromium, carbon, and nickel. Some other elements of this type of steel are manganese, nickel, and molybdenum.

The main qualities of martensitic stainless steel allow it to be useful in a wide variety of applications. This type of stainless steel can even perform different industrial functions and withstand the surrounding elements. Some products that can be made from martensitic stainless steel are cutlery, cookware, surgical and dental instruments, industrial blades, turbines, vehicle stampings, and many more.

Treating Martensitic Stainless Steels

Given the overall composition of martensitic stainless steel, it can be easily processed by heat treatment. Usually, the martensitic stainless steel may undergo the process of hardening, which allows it to be heated first to high temperatures before letting it cool rapidly.

As for minimising stresses, the same material may be reheated at lower temperatures. Alternatively, the hardened martensitic stainless steel can be reheated at a slightly higher temperature to soften it and attain intermediate hardness levels. Annealing can also be done to this type of stainless steel, which is a process that subjects the alloy to below its critical temperature. Allowing the alloy to cool for a long time after being exposed to its above critical temperature is also possible through full annealing.

Different Heat Treatment Techniques

Age hardening, annealing, quenching, and tempering are few heat treatment methods that martensitic stainless steels can handle. After all, their atoms can achieve the needed hardness and strength once they are heated and rapidly cooled. 

Age hardening is done by heating the martensitic stainless steel and allowing precipitates to form. Subsequently, the material is stored for a long time at a high temperature, allowing it to obtain increased strength. Annealing, as previously stated, is done by subjecting the alloy to below its critical temperature, ensuring that it can be easier to process. Heating, rapid cooling, and reheating are processes involved in quenching and tempering, which can make the martensitic stainless steel ductile.

To know more about heat treatment and martensitic stainless steel, just contact us at Alpha Detroit Heat Treatment.