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The metal casting process can create anything from tiny fasteners to large industrial components, all through a five-step procedure. It happens by creating a pattern and making a mold, melting and transferring the metal and finishing, cleaning, polish and inspecting the casting. While metal casting is a straightforward practice, it requires specialized skills and techniques to perfect.
At Hengchang Foundry, we have the mastery and technology to form objects of various sizes for different industries like heavy equipment and transportation. No matter the complexity of the parts you require, our professional team can produce tailored castings to deliver unique parts for your application.
What is the metal casting process? Continue reading to learn what to know about metal casting and how our metal casting services work.
When talking about a pattern, we aren’t referencing one you trace on a piece of paper. Instead, metal casting foundries refer to patterns as a replica of the object they’re casting. This pattern helps form the mold cavity, which can be made of wood, plastic, aluminum and many other suitable materials. Making a pattern is a crucial first step because the accuracy of the mold determines the accuracy of the final product.
The four steps in producing a precise pattern include:
Depending on the type of material being poured into each mold, the final, solid product will distort to a certain degree. For example, it may shrink compared to the original size of the mold. This is why each pattern has allowances for slight alterations. Additionally, patterns require a draft, or a vertical tapered wall, where professionals can extract the pattern without tampering with the molded product.
It’s now time to create the mold, which is a hollow shape that will form the metal later on in the process. While some molds are expendable, others are nonexpendable.
An expendable mold means you can’t use it again. In that case, materials like sand, plaster foam or plastic make up the mold, and they’re destroyed during the casting process. Alternatively, you can use nonexpendable molds indefinitely, as they’re often made of aluminium.
Both expendable and nonexpendable molds can support different pattern complexities and materials.
While we use a multitude of materials for metal casting, they all fall under one of two categories — ferrous and non-ferrous metals. The metals used in metal casting can include iron, zinc, aluminum, tin, copper, lead alloys and others. While a ferrous metal contains malleable iron or steel, a non-ferrous metal contains nonmalleable metal, such as copper, nickel or aluminum.
After selecting the appropriate metal type, we load it into the furnace where temperatures rise until it reaches the material’s melting point. At Warner Brothers Foundry Company, we use gas furnaces during the metal casting process, though there are two other common types of furnaces for metal casting — electric arc and induction.
Using electric furnaces is our preferred method for metal casting because it burns cleanly and efficiently. Electric furnaces also allow us to heat the metal to the necessary temperatures without using high amounts of electricity. Electric furnaces are more efficient for our process, which keeps costs lower on our end and allows us to offer lower prices on your end.
Once the material melts down, it’s transferred to a large ladle before it reaches the mold. Through gates and risers, or openings in the mold, workers or machines pour the liquid material into the mold. Once it takes shape, solidifies and cools, we eject the casting from the mold, removing excess metal from the gate and rider system before moving to the next step in the process.
Understanding how long metal casting takes depends on the material — some may cool within minutes, and others take several days.
This stage involves making the final touches and cleaning each individual part. At Hengchang Foundry Company, we go in and remove excess metal parts and begin the cleaning process, using different tools to clear away particles and dirt. The final product is the same proportion and shape as the original pattern used during step one.
Additionally, some products may require a heat treatment, such as rail clamp, hydraulic cylinder, buffer. This process alters the properties of the material through a heating and cooling technique where the metal becomes more resilient. These treatments are ideal for applications that may endure extreme weight, wet environments or freezing temperatures.
The metal casting process ends with an inspection to ensure everything is complete and up to our standards. During the final stage, we check the part’s physical structure and integrity to ensure it’ll hold up and perform the expected job.
There are destructive and nondestructive testing methods, which are put in place depending on the casting’s specifications. In particular, visual inspections include looking for cracks, accuracy and surface finishes, and more in-depth testing checks tensile strength, hardness and ductility, among other components.
No matter the industry, we inspect everything from trailer hitches and industrial equipment to small automotive parts. In the end, you’ll have a durable component that’s suited to your unique needs and operations.
The global metal casting market will be worth $12.38 billion in 2023. It is expected to grow at a CAGR of 5.3% from 2022 to 2032. With the booming castings industry, the market is witnessing an increasing demand for metal casting companies. The global casting market is currently characterized by the presence of diverse international and regional manufacturers. Metal casting companies continuously invest in developing new technologies and products to remain cost-effective and competitive. It is a good signal for the foundry like us, who export tailored valve, ring, ditch cover, agitator, etc for our customers
Ductile iron is an alloy of cast iron or grey iron in which the carbon forms into nodules as opposed to plates as it is in grey iron. This makes the metal more ductile than cast iron hence the name.
Ductile iron has greater strength and ductility than gray iron. Those properties allow it to be used effectively in a wide variety of industrial applications, including pipe, automotive components, wheels, gear boxes, pump housings, machine frames for the wind-power industry, and many more.
After produce the items, the preliminary casting inspection will use the visual. This inspection way involves using the human eye to detect surface defects, tears, misruns, cracks, cold shuts, gas evolution, molding flaws, metal penetration, slag adhesions and sand inclusions. This inspection is essential to ensure the casting adheres to visual acceptance standards. Inspection results should be documented and recorded, and every surface irregularity should be classified. Any castings with visually detected defects should be picked out and not moved to next steps or delivered to customers. The inspection way always use in the casting parts with different material, such as QT450-12, QT500-7,QT600-3 etc
Even a child playing at the beach or in a sandbox can immediately grasp how sand casting works. When you see a child mixing water into sand to make it easier to shape it into a sand castle, that child is demonstrating how combining some sand and water works so beautifully for creating a shape.
At its simplest, the sand casting process for a casting foundry is nothing more than making a cavity in the sand in the desired shape, pouring molten metal into the cavity and letting it cool. Humankind has been doing this for thousands of years. Sand is heat resistant and readily available almost anywhere on earth.
If you’ve ever noticed the way footprints made in wet sand hold their shape, you can easily imagine what likely inspired the first ancient metal workers to use wet sand to shape their cast metals. Everything after that has just refined and perfected the basic process.
The term green sand has nothing to do with the color of the sand casting material. It means there’s some moisture in the sand; when the sand is said to be green, it means the mold has not been baked or dried. This kind of molding sand is a very economical and versatile material. When desired, the foundry can add select additives can make the green sand more ideal for a specific purpose. Green sand is used in the most common sand casting processes.
Sand casting equipment within a foundry can be very basic or quite advanced, depending on the items being made. Typically, the sand is placed in a mold box, which is known as a flask. The pattern, or model, is placed in the prepared sand inside the flask to make a mold. The pattern is removed, leaving behind a perfect shape in the sand. The mold is filled with molten metal, which is allowed to cool. When the metal is sufficiently cooled, the sand mold can be broken away.
More complicated items can be cast by combining an upper and a lower section. The upper mold is known as the cope, while the bottom half is known as the drag. Once the cope and drag are ready, they can be fastened together so that molten metal can be poured into the resulting cavity. Even further detailing is possible with the addition of a core. A core is something placed inside the mold to form a negative space that no molten metal will fill. An example would be the middle of an engine block or any other cast item that requires a hollow space.
Castings made with cope and drag must provide a way to introduce the molten metal into the mold. It can be a simple vertical passage, known as a sprue. The sprue and its channel will fill with molten metal that will solidify and will need to be machined off to get the item to its final design.
In the modern foundry or casting industry, the knowledge of how each alloy will react with each potential form of mold and each potential additive allows the worker to make choices to give the finished item the desired characteristics. Metal casting is both an art and a science.
As the molten metal cools and solidifies, it will give off gasses. The molds are designed to take that into consideration and when necessary, will be constructed to allow the gasses to escape throughout the sand casting process.
Chances are good that you’re less than 10 feet from at least one cast item right now that has been through the sand casting process. There’s hardly an industry that doesn’t have some kind of need for cast materials. Some cast items are large and can weigh hundreds of pounds, while other cast items are tiny and intricate.
Almost any kind of metal can be shaped using the right sand casting equipment. Grey iron and ductile iron very well.
Modern manufacturers will usually add some water and other additives to the sand casting process to make it work better for various purposes. Different alloys and different items call for additives, including these common materials:
Relatively new technology in today’s casting foundry is 3D printed patterns and molds.
The latest 3D printing equipment is capable of manufacturing a sand mold and core in just a few hours. This can save considerable time and money in some cases.
Once the pattern is produced, sand casting proceeds as usual, but the ability to use a 3D printer to produce the pattern, molds and cores greatly speed up the process, potentially saving production costs and increasing the accuracy of the casting. If an example of the item to be sand cast already exists, it can easily be scanned to create the 3D model.
Once the program for producing the sand mold and core is perfected, it can be reproduced as many times as desired. Such sand casting equipment is a growing part of the metal casting industry. The sand casting advances of today would no doubt amaze the master sand casters from a hundred years ago — not to mention those of a thousand years ago!
In some cases, an item produced through the sand casting process requires machining, painting, or another process to bring it to completion. Oftentimes, the item will have extraneous material necessary to make a good cast but not meant to be part of the finished design. At other times, fine detailing is needed and can be added after the cast is completed. Cast Technologies has a CNC machine shop on-site in order to deliver a finished product that meets your needs. This allows us to serve our customers better, as we take responsibility for all the processes the part requires to meet its design specifications.
We have two quench furnace and a anneal furnace. For the castings parts with high class material, such as wheel brake wehd, piston cylinder, frame etc. to make sure stable mechanical property, usually will be used with heat treatment.
Heat treatment is a thermal process that accomplishes three primary improvements to the material properties of metal castings:
The heat treatment process begins with heating the metal casting to the desired temperature before cooling the metal in a controlled way to achieve the desired improvements. This heating and cooling process “locks in” the final metal microstructure and the improved material properties.
As outlined above heat treatment is used to achieve a variety of desired outcomes for a metal casting. Heat treatment can also be designed to reduce hydrogen levels, simulate in-service conditions, restore mechanical properties, and reduce stresses after a project is welded. These various outcomes are achieved with different heat treatment processes. The overarching objective of heat treatment is to achieve customer specification requirements and comply with industry standards.
While there are a range of different heat treatment processes available at Hengchang, some are used more often than others.
This process involves heating the metal casting in a furnace to an extremely hot temperature and holding for an extended period to improve chemical uniformity by diffusion. Homogenization is sometimes employed as a pre-treatment to make subsequent heat treatments more effective.
Normalizing is heating the metal casting to an elevated temperature above the transformation temperature and then air cooling it back to room temperature. This process alters the microstructure to reduce the variation in hardness and ductility within the casting. The temperatures and times are typically lower and shorter than for homogenization. Normalizing is often followed by tempering. Tempering is heating the metal casting to a temperature below the transformation temperature to lower the hardness and improve the ductility of the metal.
The use of this treatment results in an improvement in metal casting mechanical properties, related especially to increasing hardness or durability. It is often used for steel parts. Metal is heated to an elevated temperature (above the transformation temperature) and then rapidly cooled (quenched). This causes the softer initial material to transform its structure into a stronger one.
Quenching cools the metal casting after the initial heating process. The quench is typically performed in oil or water, depending on the material and specification requirements. Tempering is the last step in the hardening and tempering process and is required after the quench. It involves reheating the metal at a low temperature (below the transformation temperature) to achieve final specifications. Tempering lowers the as-quenched hardness, restores ductility, and reduces stresses of fully hardened steel.
Annealing is heating and holding the metal at an elevated temperature followed by furnace cooling to obtain the desired hardness. This is typically performed on “hardenable” ferrous alloys to reduce hardness, increase ductility, and improve the machinabilityof the casting. This process is often used on tool steels, alloy steels, and martensitic stainless steels to allow for quick rough machining prior to any hardening and tempering operation.
Solution annealing is heating and holding metal at an elevated temperature to cause constituents like carbides and undesirable phases to go into solid solution and then cooled rapidly to hold these constituents in solution. This process improves mechanical properties and the corrosion resistance of an alloy. Austenitic and duplex stainless steels are typically supplied in the solution annealed condition.
Stress relieving is heating to a relatively low temperature and holding for a long enough time to reduce residual stress within the casting. The process typically employs controlled heating and cooling rates to minimize the development of new stresses. Stress relieving is often done after rough machining prior to tight-tolerance finish machining work.
大约 4,000 年前，当青铜时代开始时，人类已经将石器时代抛在了身后，出现了金属冶炼铸造行业。 Cast Technologies 的团队非常自豪，他们来自一大批可以追溯到古代世界的熟练工匠。今天，我们使用的流程与我们远古祖先所使用的原理相同，以彻底改变世界并使世界现代化。虽然人们可能会认为电力、印刷机和计算机等东西是当代世界的基石，但事实是我们的生活方式在很大程度上取决于铸造厂的工作：汽车、航空旅行和能源生产等行业都要依赖铸件行业。
虽然现代铸造厂与人类早期发明的用简单的青铜合金制造武器和工具的原始技术几乎没有相似之处，但想法大致相同：将金属混合物熔化在一起，然后将液体倒入某种模具中。制造青铜矛头使用的技术与制造发电机零件的技术大致相同。
古人制造了武器和犁之类的东西，让他们可以放下更原始的石器。今天，铸造厂制造了我们在现代生活中所依赖的几乎无限数量的物品，包括汽车发动机、管道、链轮、飞机零件、工具和许多其他金属部件。当然，今天的铸造厂不仅限于青铜，还可以根据成品所需的特性铸造无数适合不同环境要求的金属合金零部件。
由于技术和冶金科学的进步，铸造厂有了长足的发展。最初，木炭火被用来驱动小熔炉，其温度足以熔化金属，但现在燃气或电热被用于驱动更先进的熔炉。
早期的铸造厂是一个危险的工作环境，但现代化和机械化使它们的危险性大大降低。例如，通过机器人或其他自动化设备将熔融金属倒入模具中，比使用钢包手动浇注要安全得多。
铸造厂的另一个变化涉及将熔融金属放入模具的方法。仍然使用传统的重力浇注，但现在还有其他方法可用，包括真空或加压气体浇注。
想象一下你生活在几千年前，你想用金属铸造一个简单的物品，比如一个扁平的圆盘。最简单的方法是所谓的砂模铸造.
你可以从用木头雕刻一种叫做图案的东西开始。一旦你有了你想要的形状，你就可以把它沉入沙坑，然后……非常小心！ â 你会从沙子上取下你的木制模型。做得对，这将为您在沙地上的木制模型留下完美的印象。
接下来，您将根据您希望成品具有的特性准备金属。也许你会遵循一份锡到九份铜的古老配方。你需要一个小熔炉、一个粘土熔炉，当然还有一个用于熔化的热木炭火。是的，虽然在现代铸造厂中达到必要的温度要容易得多，但原始的木炭熔炉确实可以加热到足以将铜和锡熔化在一起。
一旦你的金属熔化在一起，你就可以小心地将混合物倒入沙腔中，让金属冷却。最后，你要从沙子中取出凝固的金属盘。如果一切顺利，您将拥有一张完美的木盘金属副本。
现在让我们假设您想要制作更复杂的演员表。您可能希望将您的项目分为两个不同的部分，一个顶部和一个底部。这称为分割模式，上部称为上部，下部称为阻力部。
甚至更复杂的设计可以使用称为核心的东西进行。将型芯插入模具中以形成中空区域。
现在想象一下，您需要您的物品具有更光滑的表面。您可以通过打磨或打磨将其弄平。今天，您可以对表面进行喷砂、打磨或用研磨机将其加工光滑。从最简单的小物件（如珠宝）到最复杂且重达数百磅的大型部件（如风力涡轮机叶片），都采用了同样的通用工艺。
在物品从模具中出来后，如有必要，可以使用进一步的工艺。投掷Technologies 拥有一个现场机加工车间，可为任何组件添加最后的润色。
该表显示了不同类别的图案设备的优缺点。砂型铸造工艺.
| 优点 | 缺点 | |
| 松木 | 生产成本低。用于制作塑料图案。轻松修改。 | 不适合生产批次，除非在磨损前转化为塑料。往往会变得不准确并产生较差的表面光洁度。 | |
| 硬木 | 小批量生产成本低廉。可用作塑料图案的母版。如果涉及多个印象，相当容易修改但昂贵。 | 公平的穿着性能。小心，将在相当长的一段时间内保持相当准确。不适合大批量生产。 | |
| 塑料 | 生产成本低。聚氨酯技术提供了良好的耐磨性和准确性。根据使用的材料轻松修改。适用于与金属图案具有相同尺寸公差的大批量生产图案。 | 聚氨酯技术减少了早期塑料图案材料的许多缺点。 | |
| 金属 | 优异的穿着性能。高标准的准确性和稳定性。适用于大批量生产和外壳成型。 CAD/CAM 的改进大大降低了成本和交货时间要求。 | 昂贵。很难修改。设备不太适合从一个铸造厂转移到另一个铸造厂。 |
砂铸件或永久模具铸件？由于我们在此提供两种铸造工艺恒昌铸造，我们经常被提出这个问题。这两种铸造工艺有什么区别，哪一种更适合您的应用？让我们通过粗略的概述来消除选角的困惑。
砂铸件：生产一次性砂模，其中可能包含零件的一个或多个印模。将熔融金属倒入砂型中，然后凝固冷却，将砂子打碎，取出铸件。在大多数情况下，沙子会被回收再利用。那么什么时候砂型铸造合适呢？当生产适合小批量和大批量生产时，该工艺由材料和机械铸造性能要求驱动，只需要适度的表面光洁度和尺寸公差，需要低模具成本，以及当尺寸和配置要求零件只能做成砂铸件。可能还需要考虑其他一些因素，建议用户在最终确定零件设计之前咨询代工厂。
永久模具铸件：与砂型铸造不同，模具由铸铁或钢制成，根据零件的几何形状允许一个或多个型腔。当零件配置要求这种类型的铸件时，该工艺最适合中高产量，或者该工艺最适合铸件的应用。在大多数情况下，模具完全数控加工分型面与提供良好可重复铸造尺寸条件的锁定系统对齐。与砂型铸件相比，永久型铸件具有改进的表面光洁度，所需的加工余量更少，并且通过金属模具配置可以实现更接近的净形轮廓。然而，与砂型铸件不同的是，永久性模具铸件的尺寸有限，而且工具被证明更昂贵（尽管零件价格往往更低！）。同样，请咨询代工厂以确定适合您需求的正确工艺！
您是否更好地了解砂型铸件和永久型铸件之间的区别？您是否已决定哪个更适合您的特定应用？有关更多信息，请参阅我们的网站。
有几种铸造方法可用于生产工业制造过程所需的机器零件，包括砂型和熔模铸造。在这里，我们将探讨两者之间的一些关键异同。
金属工人广泛使用砂模铸造技术，因为它适用于铸造钢、铁、黄铜和大多数有色合金……以及重量从不到一磅到数千磅的最终产品。这砂型铸造工艺从创建沙模开始。在传统的铸造厂中，在用硬木、聚氨酯或泡沫制成最终产品的所需图案或模型后，将沙子在其周围压实以形成模具。为了保持其形状，最初用一种称为粘合剂的粘合剂对沙子进行处理，以提高其颗粒之间的附着力。然后通过将砂模分成两个或多个部分来去除图案。然后，这些部分通过称为浇注系统的输送系统被绑定以接收熔融金属。在金属充分冷却和固化后，通过摇出过程去除沙子来回收最终产品。
砂型铸造的一些主要优点概述如下：
也称为失蜡铸造，熔模铸造技术对于复杂和详细的组件是可靠的。与其他形式的金属铸造相比，金属工人使用它来制造具有近净形状的最终产品，从而减少材料、加工和劳动力成本。
熔模铸造方法首先将蜡模制成所需的铸件，然后用耐火材料（例如陶瓷）对其进行涂层。加热会使蜡熔化，留下一个空壳，其中的空隙要填充成所需的几何形状。然后将熔融金属引入这个预热的外壳中。一旦它适当地冷却和凝固，它就会通过破碎外壳来回收。
采用熔模铸造的一些主要优势包括：
多年来，熔模铸造和砂型铸造都经历了显着的改进——旨在最大限度地减少金属的使用量并降低广泛的精加工和机加工要求。尽管它们在某些方面相似，但它们之间存在一些显着差异。
两种铸造方法之间的一些相似之处包括：
熔模铸造和砂型铸造之间存在一些根本区别，包括：
砂型铸造的成型周期短，而熔模铸造工艺需要更长的时间。
砂型铸造的最终产品通常是粗糙的，具体取决于所使用的砂。其他缺陷包括夹砂、砂洗和气孔。同时，熔模铸造的产品明显更光滑。
熔模铸造所需的材料，如石蜡、硅酸钠等，比砂型铸造所需的材料（砂、粘合剂等）成本更高。砂型铸造相对便宜。
金属工人可以通过熔模铸造实现更复杂的设计，而砂型铸造可能需要额外的锥度和机械加工才能获得所需的几何形状。如果在生产运行期间需要更改设计，与制造熔模铸件所需的工具相比，砂型铸造模型更具成本效益并且需要更少的时间来修改。
由于熔模铸造的高尺寸公差 (CT 4-6)，成品零件可以有薄壁，而砂型铸造成品零件的最小壁厚为 3 到 5 毫米，因为它们的尺寸公差较低 (CT 10-13) .
砂型铸造的适应性广，因此可用于广泛的铸件，包括球墨铸铁,灰铁、钢、铝等。虽然熔模铸造可用于其他冶金，但它们通常适用于钢铸件。
由于熔模铸造可以保证一致性，因此适合大批量生产。然而，砂型铸造不能保证这种一致性。因此，使用砂型铸造方法批量生产成品零件更具挑战性。
知道合适的方法
Cast iron Pan are very popular. Most metal pans are made of Grey iron. How to clean it is the key to the life of the IRON Pan. Here some tips for reference. Now that the crusty food is gone, a simple baking soda scrub will restore it to its former, flavorless, glory. Use baking soda and water in a 2:1 ratio, it should form a thin paste. Scrub this into the pan with a soft or plastic bristle brush and then allow the paste to sit for two to five minutes. Just like the stinky aromas in your refrigerator, the baking soda neutralizes the leftover flavor that may be in the top layer of your cast iron.
Then rinse the paste out of the skillet and wipe with a paper towel or a kitchen rag. If you went really crazy with the fried catfish or boiled clams in the skillet and you're about to make Grandma's pear upside down cake in it, go ahead and give the skillet another baking soda bath. If the flavors of the previous dish weren't too strong, skip the second scrub and follow these steps to re-season your skillet.
The formation process of graphite in cast iron is called graphitization process.
It can be divided into three stages:
1.Liquid phase hypoeutectic crystallization stage.It include the direct crystallization of primary graphite from the liquid phase of hypereutectic components, the crystallization of austenite from the liquid phase of eutectic components and the graphite formed by primary cementite decomposed during high temperature annealing.
2.Eutectic transition phases between hypoeutectoid transitions.It include the direct precipitation of secondary graphite from austenite and the graphite formed by the decomposition of secondary cementite in this temperature range.
3.Co-folding transition stage.Including the eutectoid graphite formed during the co-folding transformation and the graphite formed by the decomposition of the eutectoid cementite during annealing.
The structure of cast iron depends on the degree of graphitization. In order to obtain the required structure, the key is to control the degree of graphitization. Practice has proved that many factors such as the chemical composition of cast iron, the cooling rate of cast iron crystals, the overheating and standing of molten iron, etc., all affect graphitization and the microstructure of cast iron.
Factors affecting graphitization of cast iron:
1.Influence of chemical composition.
2.Influence of cooling rate.
3.The effect of overheating and high temperature standing of cast iron.
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