The melting point refers to the temperature at which any material changes from solid to liquid (melt). It’s also referred to as the melting temperature of that element. Metals have different melting points depending on chemical composition and atomic structure. Understanding the melting temperature for metals is essential in selecting one that matches your application, whether you’re using forging, welding, or casting equipment. So, what’s the steel’s melting point?
The melting point of steel ranges from 1370°C to 1530°C (2500°F to 2800°F). This melting temperature of steel depends on the specific grade since they all have different compositions.
Let’s dive into more details about the steel’s melting temperature, properties, and how it compares to other metals.
Properties of Steel
Due to its excellent characteristics like corrosion resistance, yield strength, and more, steel is one of the most common metals worldwide. The global steel market is estimated to be US$ 1,893.9 billion in 2023, up from US$ 1,823.5 billion in 2022.
Steel combines iron, carbon, and sometimes other metals or elements such as manganese, chromium, and vanadium. The following are some characteristics of steel in addition to its high melting temperature:
- High tensile strength: Steel is exceptionally strong, making it the second most robust metal on earth. It can withstand high tension or pulling force without breaking or deforming. This makes it ideal for constructing railways, roads, bridges, buildings, stadiums, and other structures that support heavy loads.
- Durability: Steel, especially stainless steel, is resistant to impact, fatigue, wear, and external forces. This makes it suitable for applications that require reliability and longevity, such as medical equipment, culinary tools, etc.
- Conductivity: Steel is a relatively good conductor of electricity and heat, making it an excellent material for heat exchangers, electrical transmission lines, and electrical wiring.
- Ductility: Steel has good ductility, meaning you can stretch and bend it without becoming too thin or breaking it. Ductility helps form different shapes and sizes.
- Weldability: You can easily join pieces of steel together through welding to form bigger components. However, it’s good to note that steel with high carbon levels displays poor weldability.
- Magnetic properties: Steel is a ferromagnetic material because it has magnetic properties. This makes it a good material for transformers, motors, generators, and magnetic storage devices.
- Recyclability: Steel is 100% recyclable. This means you can recycle steel and still retain all its properties. As a result, there will be less environmental pollution.
Melting Point of Steel Explained
The melting point of steel refers to the temperature at which the steel will transition from a solid phase to a liquid state. Steel melting temperatures are between 1370°C and 1530°C (2500°F to 2800°F).
However, the exact melting point depends on the type of steel alloy. That’s because alloys contain elements such as nickel, manganese, chromium, and vanadium., which impact the melting temperatures differently.
For example, stainless steel’s melting point differs from carbon steel’s. Likewise, the melting point of low-carbon steel differs from the melting point of high-carbon steel, as you’ll notice later in this article.
Due to steel’s high melting temperatures, this metal is perfect for applications requiring high heat exposure.
Factors Affecting Melting Point of Steel
Steel, in its pure solid phase, has a higher melting point. However, some factors can influence the steel’s melting point. These factors include the following:
- Alloy: Alloys are a combination of different metals. For example, stainless steel is made up of several elements that, when combined, change the steel structure, characteristics, and properties. This means that the melting temperature can increase or decrease depending on the composition.
- Impurities: Impurities, even in small amounts, can disrupt the crystal lattice, lowering the steel’s melting point. Such impurities may include oxygen, nitrogen, sulfur, and phosphorus.
- Additives: Additives are pure metals added to steel to improve some properties. While impurities lower the steel’s melting point, additives, on the other hand, can be added to increase the melting point. Examples of such additives are copper, nickel, tungsten, and titanium.
- Pressure: Any change in pressure affects steel’s melting point. Under high pressure, the melting point increases, while low pressure can reduce the melting point.
Different Types of Steel and Their Melting Points
Let’s look at the four types of steel and their melting points.
This type is the most common among the four types of steel. It’s primarily a mixture of carbon and iron, with the rest being trace amounts of other elements. It has a carbon content ranging from 0.05% to 2.0%. The melting point is between 1410°C (2570 °F) and around 1530°C. It’s divided into the following:
- Low- or medium-carbon steel (up to 0.30% carbon)
- Medium-carbon steel (0.3%–0.6% carbon)
- High-carbon steel (0.60% to 2.00%)
Unlike carbon steel, alloy steel contains additional alloying elements such as nickel and manganese. These additional elements improve the steel’s strength, wear and corrosion resistance, and hardness.
Stainless steel is an alloy steel type made up of iron, carbon, chromium, and other components such as nickel. Stainless steel has a chromium content of 10.5%, making it more corrosion-resistant. The melting point for stainless steel is 1375°C–1530°C (2500–2785°F).
As the name suggests, tool steel is a type of steel designed for cutting and drilling equipment. It contains elements such as chromium, tungsten, or vanadium to enhance its hardness and wear resistance at high temperatures. The melting point for tool steel is around 1420°C.
Comparing the Melting Points
The table below shows a comparison of the steel’s melting point with other commonly used metals:
|Melting Temperature (Celsius (C))
The Process of Melting Steel
Steel is melted in steelmaking furnaces to achieve a liquid state. Two appliances are used in modern steelmaking: electric arc furnaces (EAFs) and basic oxygen furnaces (BOFs), also known as blast furnaces. The two appliances define the process of steel making.
Electric Arc Process (EAP)
An electric arc furnace uses electricity to generate heat. Scrap metal, plus any other additives, is put on the furnace. Once the electric arc furnace energizes, it creates an arc between the electrodes and the scrap metal.
The arc generates temperatures of up to 3,000°C, causing the scraps to melt. After melting, the impurities are removed to achieve pure molten steel. Once the purity level is achieved, alloying elements are added to the molten steel to improve its properties. After achieving the desired composition, the molten steel is cast, rolled, or forged into desirable shapes.
Raw iron ore, coal, or limestone are the raw materials used in steel making. The converter converts the raw material into pig iron. The pig iron and small quantities of scrap metal are put into a blast furnace. Hot air is blown into the furnace using nozzles to raise the temperature to the required level.
The hot air may be rich in pure oxygen, which oxidizes impurities such as sulfur and creates gaseous byproducts such as carbon dioxide and lag. The high heat also brings down the carbon content to the desired level. From here, the process is the same as that of EAF, from the point of removing impurities.
Just like in any manufacturing industry, safety is vital during steelmaking. Due to the high melting temperature of steel, some measures are put into place, including the following:
- Ensuring all personnel are qualified and knowledgeable about safety
- Wearing protective gear such as goggles and heat-resistant clothing
- Ensuring adequate ventilation systems
- Implementing fire barrier and emergency response protocols
Costs Associated With Melting Steel
Melting steel costs roughly $550–$800 per ton. However, this may depend on factors such as supply and demand, the method used, and location.
The cost of melting steel comprises energy, labor, material, and transportation costs, which will all determine the exact cost of producing steel.
|Science Fact: The method and efficiency of heating can affect the quality and characteristics of the molten steel.
Practical Applications of Steel
Steel is versatile due to its properties, making it common in many industries, from construction, energy, and automotive to aerospace. If you’re wondering how the steel’s melting point is useful in real life, we’ll provide you with a few examples in different fields.
The manufacturing industry, including automotive, aerospace, and machinery, relies heavily on the melting point of steel during the production of different components. Knowing the melting point during fabrication can help the manufacturer determine the temperature at which steel can be molded, shaped, or welded.
Understanding steel’s melting point can help determine the perfect steel grade for different applications. For example, beams and columns require different steel compositions and melting points to meet the project’s specifications and safety standards.
Energy and Power Sectors
Due to its high tolerance to extreme temperatures and exposure and conditions, steel can be used in industries requiring metals with higher melting points, and none scream so much more than the energy sector—power plants, turbines, pipelines, and transmission towers.
Consequences of Melting Steel
Although melting steel has great industrial benefits, the process involved also has negative consequences. These include the following:
- Health consequences: Melting steel involves extremely high temperatures and melting points that can cause bodily harm if proper measures are not taken. You must abide by the manufacturing SOPs of your steel plant at all times to prevent severe burns, toxic smoke irritation, etc.
- Environmental consequences: Experts indicate that steel production is the highest CO2-producing activity in the world since most energy comes from burning coal. The coking process also introduces pollutants into the water, such as cyanide, sulfides, ammonium, and ammonia, all of which are carcinogenic in nature.
Melting point is an important property of any metal. It’s when a metal changes from a solid state to a liquid form. The steel’s melting point is between 1370°C and 1530°C (2500°F), depending on its type and composition.
Understanding the melting point of steel can help you choose the steel type that meets the requirements of your specific project. Melting points in steel can also help you avoid defects and imperfections arising from improper heating. Factors affecting steel’s melting point may include alloys, additives, impurities, and pressure.