Steel is the industry standard material for the manufacture of mold tool. It is considered a good all-round material embodying many of the desirable characteristics that we are looking for.
There are many different types of steel available for a wide range of general-purpose applications and many specialist steels for more extreme applications. For our purposes, however, We will restrict our discussion to those steels commonly used for the manufacturer of injection mold tools.
A number of steels are used for the construction of mold tools. All steels contain carbon and, in general, the higher the level of carbon, the tougher and stronger the steel will be. Sometimes plain or mild steel is used with low carbon content, and on other occasions higher carbon content steel is used, often alloyed with other elements to improve the properties of the steel. Carbon steels that have been alloyed with other elements to increase their performance, are usually called tool steels or alloy tool steels.
For nearly all mold steels the most common alloying elements are chromium, nickel’ molyhdejium,tungsten cobalt and vanadium. For most mold steels, four of these elements are normally used.
Chromium: Improves surface resistance to wear and corrosion.
Nickel: Improves low-temperature toughness and increases fatigue resistance:.
Vanadium: Increases strength, hardness and impact resistance.
Tungsten: Increases strength, toughness and higher to temperature performance.
Although these alloying elements are designed to improve certain properties, it must be noted that they can also have adverse effects on other properties* For example, with increasing chtomium content the thermal conductivity of -alloy steel decreases