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8418 TOOL STEEL

8418 STEEL GRADE COMPARISON AND CHEMICAL COMPOSITION COMPARISON

APPLICATION

8418 steel is a high-quality hot work die steel known for its excellent thermal fatigue resistance and high temperature strength. In the field of die-casting molds, 8418 steel is widely used for die-casting of non-ferrous metals such as aluminum alloys and magnesium alloys. Its excellent heat resistance and hot cracking resistance can significantly extend the life of the mold. 8418 steel is particularly suitable for manufacturing large and complex die-casting molds, such as production molds for automotive engine cylinder blocks, gearbox housings, and other components.

In the application of hot forging molds, 8418 steel exhibits excellent high-temperature strength and toughness. 8418 steel is commonly used in the manufacture of forging hammer heads, hot stamping dies, and other mold components that require severe impact and high temperature. The addition of alloying elements such as chromium, molybdenum, and vanadium to 8418 steel enables it to maintain stable mechanical properties even at high temperatures of 600 ℃, effectively resisting thermal wear and plastic deformation.

8418 steel is also suitable for the manufacturing of plastic molds and extrusion molds. During the injection molding process of high-performance composite materials such as glass fiber reinforced plastic, 8418 steel material can withstand the high-temperature corrosion and wear of the resin. The uniform microstructure and good heat treatment performance of 8418 steel ensure the dimensional stability and surface smoothness requirements of the mold during long-term use.

8418 STEEL CHARACTERISTICS

8418 steel has excellent high-temperature strength and can maintain a tensile strength of over 500MPa even in a working environment of 600 ℃, thanks to its precise molybdenum and vanadium element ratio. This high temperature stability enables 8418 steel to effectively resist deformation failure caused by thermal stress during continuous die casting operations.

The heat fatigue resistance of 8418 steel is outstanding, and the specially treated grain boundary structure can withstand over 100000 thermal cycles. The thermal expansion coefficient of 8418 steel matches that of most die-casting alloys, significantly reducing the probability of thermal cracks on the mold surface and extending the mold's service life by more than 30%.

In terms of toughness performance, 8418 steel can achieve an impact energy of over 25J through optimized quenching and tempering processes. This high toughness makes 8418 steel particularly suitable for manufacturing hot forging dies that can withstand severe mechanical impacts, such as crankshaft forging dies and other heavy-duty machining scenarios.

Thermal conductivity is another advantage of 8418 steel, with a thermal conductivity of 36W/(m · K), which is about 15% higher than conventional H13 steel. The characteristic of 8418 steel is beneficial for rapid heat dissipation of molds, reducing the risk of local overheating, and ensuring the stability of continuous production.

In terms of corrosion resistance, the 3% chromium content in 8418 steel forms a dense oxide film, which can effectively resist the erosion of aluminum alloy melt. When molding chlorine containing plastics such as PVC, the corrosion resistance of 8418 steel is 2-3 times higher than that of ordinary mold steel.

The processing performance is worth paying attention to. The annealing hardness of 8418 steel is controlled within the range of 180-220HB, and the machinability index reaches 65%. The uniform microstructure of 8418 steel ensures a surface finish of Ra0.2 μ m or less during precision machining.

The heat treatment response of 8418 steel is good, and the quenching temperature window is wide up to 1020-1080 ℃. The graded quenching process can effectively control the deformation of 8418 steel, and the hardness uniformity deviation after vacuum heat treatment does not exceed ± 1HRC.