An Introduction To Forging Steel Processes
Steel is one of the most versatile materials out there. It is used to manufacture different kinds of products that are used in various sectors. Now, there are many processes that are used to cut and mold steel into desired shapes and sizes. These methods either require the application of heat or not. Now, forging is a kind of steel molding process where heat is used. Altogether, it has its pros and cons, despite all that, it is the most popular steel shaping technique out there. It is crucial to know what process is used to manufacture steel before choosing the right one for your project. The steel-making process helps determine its features.
What exactly is Forging?
Forging is a process that is used to shape metal. It is a method where metal is heated in a fire, and after it reaches a certain temperature, it is molded using external force. The use of Forging tools like hammers and tongs is one way to apply that external force. Forging is a process that is popular both at small levels and at industrial levels. Blacksmiths have been using the forging technique to mold metal for centuries. Now, there are many industries in Nepal, and abroad, that using forging. The process is the most popular one used to shape steel.
Process of Steel Forging
When it comes to steel forging, there are so many steps to it. As mentioned before, steel forging is a sophisticated process, as it determines the quality of the steel. There is the regular forging where heat is used entirely to manufacture steel. However, at the same time, there is cold forging where, instead of heat, the pressure is applied to steel to produce it. When the cold forging process is used to produce steel at a small level, a forging hammer is also used.
The forging hammer is a traditional forging tool that has been in use by blacksmiths for decades now. Anyone looking to find the answer to the question – what is forging, also needs to know about the different types of forging. There are different steps in the steel fabrication process. All of which, if carried out with great precision, leads to forged steel that is of the highest quality.
Die Design and Making
Die design is one of the most popular methods used these days for shaping metals and mainly steel. It is also quite cost-effective. However, it is more expensive than casting molds. There are mainly three types of molds that steel forging dies include. These are forging dies, trimming dies, and flattening dies.
Billet Cutting
Billet cutting is the next crucial in the forging process. After dying design and making, the steel is taken for the cutting process, where it is cut into desired shapes and sizes. A lot of times, even heat is used to achieve this feat. The steel is heated in the furnace before cutting.
Closed Die Forging
Generally, the die has two parts – the fixed half and the ejector are used in die design and making. These are used in the closed die forging to get the steel in an accurate shape. After the closed die forging process, there is often an extra layer of unnecessary steel left on the outside. It is called flash.
Trimming
The trimming step calls for the use of trimming dies. The flash, which is the extra layer of steel gathered on the edges, after the closed die forging process. It is trimmed using the trimming dies. The steel structure is put between the two die layers and pressed hard to get the desired end product.
Heating
Heating or giving heat treatment is the next step in the steel forging process. Applying heat to the dead steel or any steel, in general, ensures strength and longevity. There are so many steps in the heat treatment process, and they are normalizing, quenching, annealing, tempering & hardening, and solution treatment.
Shot Blasting
Shot blasting is a process that is carried out to achieve a more finished and shinier-looking end product. A lot of times, forged steel might develop scales, the step is also followed to get rid of them.
Machining
It should be ensured that the tolerance level of forged steel is really tight. And generally, the steps mentioned above are enough for the product to develop the quality. However, at times, just to ensure, the forged steel goes through the machining process. Equipment like NC Lathe and CNC is used for the machining process.
Surface Treatment
The surface treatment is the last step before inspection in the steel forging process. Generally, the surface of the steel is treated only with water, oil, or anti-rust painting. However, at times, steel is also treated with color painting, zinc plating, electro painting, and so on.
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Types of Steel Forging
The use of different types of steel in the forging process is quite common. Two of the most popular kinds of steel used in the forging process are stainless steel and alloy. The use of these types of steel in the process gives the end product great strength, resistance, and various other qualities. Both stainless steel and alloy steel have subtypes. For instance, 304/ 304L in the case of stainless steel and silicon and nickel alloy steel in the case of alloy steel. These grades and types are the ones that are mainly responsible for the overall differences in the properties of steel.
1. Stainless Steel Forging
304/ 304L stainless steel is the most popular choice when it comes to stainless steel forging. It does require a higher temperature than other types. If you’re looking for an end product that is more resistant to corrosion, choose 316/ 316L stainless steel for the forging process. Forged stainless steel has a wide range of applications. In general, it is stronger, more durable, and flexible than other types of steel. It is widely used in sectors such as aerospace, marine, firearms and defense, and so on. The four different kinds of stainless steel used in the forging process are austenitic, martensitic, precipitation hardened, and duplex.
2. Alloy Steel Forging
Alloy steel is forged by mixing numerous elements to the core steel mixture of iron and carbon. These elements offer unique properties to the end product of the resultant alloy steel. For example, Nickel and Copper make the steel stronger, and also, improves the corrosion resistance. In the same way, the use of elements like Chromium, Vanadium, Molybdenum, and Tungsten in the formation of alloy steel creates a layer of carbide on the outside of steel. This makes the alloy even stronger. Other elements such as Manganese, Molybdenum, and Cobalt are also used in the alloy steel forging process.
Applications of Forging
Depending on the grade and type of forged steel, it is used in so many areas. Forged steel has attributes such as high strength, durability, resistance to oxidation and corrosion, and the ability to withhold extreme pressure. Of course, all these properties depend highly on the steel texture and the types of steel. One of the most crucial applications of forged steel is in the sector of aerospace and aviation. The steel is used to manufacture the engines, the outer surfaces, and many other components of aircraft and rocket ships. Since these machines need to withstand extreme pressure, the use of forged steel is the right option in their case.
Yet, another application of forging is in the sector of automotive. Forged steel is used to manufacture different parts of vehicles such as cars, buses, bikes, and so many others. These generally include engines and pipes.
What Are The Operations Of Forging?
The use of steel gives these parts the required durability and resistance that they need. Forging also has a wide range of applications in the industrial sector. They are used to make different kinds of tools and equipment, large and small machinery, and so many others. Depending on how sophisticated the field is, different steel forging types are used in the process.
In the area of electric power generation and transmission as well, forged steel is highly used. Steel plays a major role in the development of the infrastructure which ensures that all the processes in the field are carried out safely and with much ease. Forged steel is also highly used in the sector of defense and marine. They are used to build various kinds of weapons, develop new and advanced technologies, and so on. Other areas where steel is highly used include agriculture, petrochemicals, railways, general tools and equipment, and so on.
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Forging Quality Analysis
Forging Quality Analysis is conducted to determine the overall quality of forged steel and the effectiveness of the forging process. There are so many different kinds and phases of forging quality analysis. First and foremost, there is physical testing. Under this analysis process, properties such as hardness, strength, impact resistance, and so on are tested. There are so many different types of equipment like Universal Testing Machine, Hardness Testing Machine, Impact Testing Machine, Metallurgical Microscope, and so on that are used during this process. The samples of forged steel are stored for a particular duration, and it is during this time that the tests are carried out to determine the overall quality.
In the same way, there’s chemical analysis. The analysis is performed to identify the elements that have been used to make the forged steel. The testing process is able to identify elements such as Nickel, Chromium, Iron, Copper, Nitrogen, and so on. Samples of forged steel, including scraps, are collected and stored for a limited amount of time.
What Is Forging Used For?
Forging is used when the tests are conducted. The equipment that is used to conduct the test is a spectrometer. Generally, it’s a 24 channel spectrometer. The heat poured is also tested on the same device. Apart from the said physical and chemical test, there are also other kinds of tests like corrosion test, mechanical porosity test, tensile strength test, microstructure test, dye penetrate test, and so on.
The surface defects test is also conducted. The analysis is made using the DP test and MPI test. In the same way, internal casting defects are analyzed using the RT Testing procedure. Visual Inspection and other surface finish checks are also carried out using SP 55 and other reference standards. Radiography is another one of such tests that are performed during the process.
Hot Forging Process and Its Applications
There are mainly three different forging techniques – warm forging, cold forging, and hot forging. Hot forging is the most popular forging technique. In this process, to forge the steel, it is heated to reach a temperature between 400 and 700 degrees Celsius. The range is above the recrystallization temperature, which means that when the steel gets this hot, new grains of crystals are formed in the metal, in this case, steel. One of the advantages of the hot forging process is that it helps avoid strain hardening of the metal. With the hot forging technique, it becomes easier to achieve the easy flow of metal. Recrystallization and Recovery of steel are possible seamlessly. And most importantly, the amount of resources and mainly the force required for hot forging is comparatively less than other types of forging.
Considering the features of hot forged steel, it is used mainly to build critical components, or safety parts to be specific. Sectors like Automotives, Aviation, Aerospace, and so on are the major ones that require hot forged steel products. Hot forged steel is used to manufacture parts of the engine such as pistons, cams, balance shafts, and so on, and brake components such as brake plates, brake handles, brake carriers, and so on. It is also used to make components of driving gear, powertrain, and undercarriage. In the field of aerospace, hot forged steel is used to make components of landing gear, rotor systems, fittings and guide rails, and so on.
The Difference: Forging vs Casting
Both forging and casting are processes that help in the shaping of steel. Both are equally popular techniques, however, they are used depending on the type of steel or the purpose. The main difference between forging and casting is that in the casting process, the steel is heated up to a point where it melts completely. Then, the melted steel is poured into molds and vessels to create desired shapes with it. On the other hand, forging is the process where thermal or mechanical pressure is applied to the steel, and as a result, its shape changes completely while in the solid-state. When it comes to advantages, there are quite a few in both cases.
Casting Process
When you use casting as a process to mild steel, there is no upper size limit to weight. The manufacturers have a large number of options when it comes to the elements or the alloys. Generally, it is quite tough to form alloys with elements such as Chromium and Nickel, however, when steel is in the molten state, any element can be added to it. One of the best advantages of casting is that it is quite easy to make complicated or difficult-shaped parts with this process. Overall, the process of casting, including the tooling process, is quite affordable.
Forging, on the other hand, is a technique that makes the end product quite stronger. As a result, it is able to handle impacts in a much better manner. Generally, during this process, there is very little chance of the steel or metal developing deformities like the occurrence of porosities, shrinkage, cavities, and cold pour issues. During the forging process, the steel develops a tight grain structure. This makes the steel mechanically stronger than any other steel molding process. Also, there is no need to use The structure also makes the structure super resistant to wear and corrosion.
Forged Steel Fittings and Its Types
There are so many different kinds of products that are made using forged steel, and one of them is forged steel fittings. The advantage of using forged steel to make all these products is that they inherit the remarkable attributes of steel. For instance, the immense strength and durability, resistance to corrosion and oxidation, ability to handle extreme pressure, and so on. Now, forged steel fittings, like any other fittings are used to connect pipes. In this case, the ones that are made using steel.
When the fittings are weak, it doesn’t really matter how strong the pipe is, as, by using them, you land up compromising the overall durability of the structure. Needless to say, how troublesome it gets when there is a leakage in the system. Therefore, it is recommended that you use only the best quality fittings to connect your pipes, and if possible, forged steel fittings. Now, there are different types of forged steel fittings. These differ in shapes and usage.
Tees
Tees are T-shaped fittings, and normally they are used to connect three pipes together. They are used to branch out water supply in two directions. These are available in different alloys, and you could get the one that best suits the size of your pipes.
Elbows
Elbow fittings are yet another type of fittings that connects two pipes together. They are used in situations when one needs to change the direction of the flow of water. The reason why it’s called elbow fittings is that it’s shaped like an elbow.
Couplings
Generally, couplings are used to let the pipe run further, or change the size of the pipes. These are also available in various sizes. Couplings are joined with pipes either through the soldering process or by using glue. These are available in different alloys, including stainless steel.
Unions
Unions can be regarded as the alternative to couplings. They are also used as couplings, but the only difference is that they can be threaded directly into the pipe. It is used in situations where gluing and soldering are not an option.
Bushings
The bushing is a kind of fitting where you can join a pipe with a larger circumference to a pipe with a smaller circumference. These are available in numerous sizes, and you could pick the one that best suits the size of your pipes. They are also available in numerous alloys.
Cross
Cross pipe fittings are also known as four-way pipe fittings because of the four openings. At a single time, four pipes can be connected to each other through the cross. Generally, the pipes are connected in a manner that there are one inlet and three outlets. These are available in various alloys including stainless steel. Also, they are found in different sizes.
Plug
The plug is a pipe component and a fitting type that is used to close the end of a pipe. It is available in various materials including steel. Generally, a forged stainless steel plug is used in the case of stainless steel pipes. Durability and resistance to corrosion are two properties that ensure that the plug lasts for a long time.
Forging: Pros And Cons
Forging is without a doubt one of the best steel molding processes. It is affordable, easier, and less time-consuming. The advantages of forging certainly outweigh the disadvantages. One of the main advantages of forging is that it offers a high amount of strength to the steel. The amount is generally higher than that offered by casting or any other steel molding process. The manufacturers of steel can make quite a few shapes with steel using this molding process. As mentioned above, it is a process that is quite easy to understand, so anyone with the least amount of technical skills can easily learn and effortlessly carry out the process. The amount of resources needed for this technique is very minimal, and even the experts need not be that experienced, so, overall, it is the one that helps you save a lot of money during production.
Advantages And Disadvantages Of Forging
Now, though the forging process has quite a few advantages, it also has a few disadvantages. These are not enough for you to get inclined towards other molding processes, but still, it’s beneficial in various situations to consider them. After the initial forging process, there is always the need for the steel to go through a secondary finishing process. It takes quite a bit of money to keep it well maintained. Also, there might be limitations to the size of steel that can be forged at any given time. So, there is also a limitation to the production amount and time. It is crucial for the steel to be forged at a definite temperature, otherwise, there is a chance of distortion. There are limitations to the metals or materials that can be molded using the forging process. So, the manufacturers need to be quite considerate about it.
Growing Use Of Forging Stainless Steel In Nepal
Nepal is a country that is undergoing a lot of infrastructural changes. There are many architectural projects that are in progress at the moment. These projects include malls and shopping complexes, colonies and apartments, office buildings, and so many others. Even when you step outside the city areas, there are so many projects like hydropower projects and dams, transmission towers, and so many others. In all these areas, forged stainless steel is used highly.
Forged stainless steel has exceptional attributes like high tensile strength, resistance to wear and corrosion, and so many others. These virtues make the steel ideal for use in sophisticated areas that require strong and durable materials. Whether it’s the communication sector, or power, construction sector, or automotive, there is a huge scope of use of forging stainless steel in the country.
Construction Of Forging Steel
In Nepal, stainless steel is used on the outer surfaces of buildings, as it can withstand extreme weather conditions. They are also used on the inside in the form of railings, furniture. and other steel-based products. Forged steel is one of the top choices when it comes to making steel architecture as well. The beams used to make steel architecture are often made using forged stainless steel. There is a very high demand for forged stainless steel in construction projects.
Pipes and fittings are products that are generally manufactured using forged stainless steel. People have started to realize the importance and usability of forged stainless steel, and that is the reason why there is a growing use of forging stainless steel in Nepal. Considering the attributes of the material, the manufacturers of different products and even the consumers have slowly inclined towards stainless steel rather than other materials.
Metal Forging: 5 Things To Consider
Now, there are quite a few things that you need to consider when it comes to metal forging. Metal forging has quite a few advantages to its name, however, it also has a few limitations. If you’re looking to get your hands on forged metal, whether it’s pure metal, steel, or other alloys, you need to carefully consider the nature of your project, and few other attributes of the material itself. In most cases, forged metal or alloy is the ideal material to be used, but there might be few areas where using metal casting can prove to be more beneficial. So, do consider the following things when it comes to metal forging.
Size Of The Finished Product
Size is one of the limitations of metal forging. You cannot forge a large-sized piece of metal or alloy at the same time. This doesn’t just slow down the production capacity of steel, but also, makes the entire process quite expensive to carry out. If you’re in need of forged metal, in a large amount, or any other kind of metal, you have to consider this small detail before the pick.
Design Of The Component
There are a few restrictions when it comes to the design of the component. Generally, the metal molding or shaping process, on its own, is usually enough for the metal or alloy to gain the final look. However, when it comes to metal forging, the molded metal or alloy needs to go through a second step as well. This secondary step helps improve the design aspect of the component.
Alloy Selection
There are so many varieties and grades of steel available out there. These differ in terms of the attributes that they possess. These attributes are the direct impact of the elements that are used to create the alloy. So, in this particular case, more than the forged or casting process, you should rather look into the type of alloy, or the elements used to make these alloys to pick one.
Internal Strength Of The Component
One of the reasons why stainless steel is used so highly is because it is known for its strength, and to be specific the high tensile strength. The difference in the molding process, whether it’s forging or castings tends to mess with the strength level. Depending on your need, you could choose the ideal steel type for you, whether the one that is cast or forged.
Affordability
The overall cost of the steel depends on a lot of aspects – the elements used to create the alloy, the molding process, and so on. Not always the most expensive option is the right one. You should choose the one that best suits your needs, or more importantly, the nature of your project. Always make sure to prioritize your budget during your involvement in any project.
Forging is a crucial step in the manufacturing of steel, as it determines the quality of the end product. You should only go for the steel produced by companies that pay special attention to the forging process. Now, if you’re looking to buy forged steel for use in any kind of project, you could contact Hama Steel. They are known for their excellent product quality and affordability. If you’re not quite sure which grade or type of steel to pick for your project, you could ask for consultation services from the experts at Hama Steel. It is the best steel company in the nation.