What is the difference between hot die steel and cold die st
2020-07-10 16:38:221. Different functional requirements
Hot die steel: high temperature strength, excellent endurance, excellent wear resistance, excellent heat resistance fatigue, high hardenability, etc.
Cold working die steel: higher wear resistance, higher strength and tolerance, stronger bite resistance, heat softening ability, etc.
2. Different categories
There are many classification methods for hot die steel, which can be classified according to the content of alloying elements and the function after heat treatment, according to the disposal, or according to alloying elements. According to the classification of alloy elements, it can be divided into low alloy hot die steel (Tungsten, chromium and molybdenum), medium alloy hot die steel and high alloy hot die steel (Tungsten, molybdenum and chromium).
In terms of steel types, cold die steels are mostly eutectoid steels and Lystenitic steels, which generally belong to tool steels.
Extension materials:
1. Carbon content
Generally medium carbon, the mass fraction of carbon is 0.3% ~ 0.6%. Ensure that the material has higher strength and hardness, higher hardenability and better plasticity, tolerance.
2. Alloying elements
The alloying elements added include Cr, Mn, Si, Ni, W, Mo, V and other alloying elements. The function of Cr, Mn, Si and Ni alloy elements is to strengthen ferrite and advance hardenability. W and Mo alloy elements are to prevent tempering brittleness, Cr, W and Si alloy elements can advance phase transition temperature, so that the mold in the process of alternating heating and cooling will not occur phase transition and a large volume change, and then advance its heat fatigue resistance ability.
In addition, W, Mo, V, etc. in the tempering process of carbide precipitation and secondary hardening, so that hot die steel at a higher temperature still adhere to the appropriate high hardness, this is one of the important conditions for the normal work of hot die steel, Cr, Si can advance the oxidation resistance of steel.
