What determines the melting point of steel?
Depending on its structure, steel can have different melting points. Most steel tools and components operate at temperatures far below their melting points. Therefore, most end users of steel products do not encounter this issue in practice. However, for those working in steel processing or manufacturing, understanding the melting temperature is critical for proper execution of technological processes.
Why do different steel grades melt at different temperatures?
The versatility of steel is due to it being one of the most universal materials. Depending on its chemical composition, structure, and phase, steel can exhibit very diverse properties.
As we intuitively know, to process a material, the tool used must be harder than the material being processed. Uniquely, in the case of steel, a steel bar can be divided into two parts and, after appropriate heat treatment, one part can be used to machine the other. What causes this remarkable behavior?
What is steel?
Steel is an alloy of iron and carbon. All chemical elements added to steel during manufacturing to modify its properties are called alloying elements. 
These include chromium, silicon, manganese, nickel, niobium, boron, molybdenum, and others. They may increase hardness, ductility, or influence the melting point.
Depending on the amount of modifying components, steel may have a ferritic or austenitic structure. This determines its magnetic properties, strength, and melting temperature.
How does the melting point affect steel properties?
The melting temperature of steel is essential for those involved in casting steel components. In plastic working of steel, processes are conducted in three main temperature ranges: cold, warm, and hot forming. The melting point is critical for defining these ranges. Typically, these are referenced relative to the material’s melting point. Roughly, cold working occurs up to ~0.4 Tₘ, and hot working above ~0.9 Tₘ (where Tₘ is the melting temperature).
What is the melting point of steel?
As mentioned, steel’s properties vary greatly depending on its type. Since steel is an alloy, we refer to a melting range rather than a precise point. The presence of multiple elements prevents a sharply defined melting point.
Carbon steels melt within the range of 1370–1540 °C, while stainless steels melt around 1400–1530 °C. (Pure iron melts at 1538 °C, but due to its softness, it is rarely used in practical applications.)
How is steel’s melting point measured?
To determine the melting point, a furnace with a thermocouple capable of precise high-temperature measurement is required.
When steel transitions from solid to liquid, energy input is needed. During melting, the sample’s temperature stops rising. The measurement system records temperature over time, and the temperature increase resumes only after the material is fully melted. This recorded change helps define the melting range.
What metals have the highest melting points?
Among metals with the highest melting points are:
Tungsten – 3400 °C
Rhenium – 3186 °C