刃物教室

複合鋼材の鍛造工程及び熱処理Forging process and heat treatment of Clad Steel material

複合鋼材は既に着鋼している材料の為、そのまま加熱を行って下さい。刃鋼の炭素量によっても変える必要があります。火造り温度が低いと変形しにくいため無理な加工となり割れを生じ、又高すぎると結晶粒を粗くし、鋼の性質を悪化させ焼入れ効果が悪くなります。
火造り後の冷却に当っては、内部歪を少なくする為、藁灰、石灰粉末、又は熱砂中で徐冷するか、600℃〜650℃に加熱した炉の中で冷却すれば効果があります。
特に良品質の刃鋼、刃物には鍛造後の徐冷を施行して下さい。刃鋼の焼割れ防止にも効果があります。

Since the composite steel material is already applied, heat it as it is.
It also needs to be changed according to the carbon content of the blade steel.
If the temperature is low, it is hard to deform, so it will be difficult to process and crack.
In addition, if it is too high, the crystal grains will become coarse, the properties of the steel will be deteriorated, and the quenching effect will be deteriorated.
For cooling after firing, to reduce internal strain, slowly cool in straw ash, lime powder, or hot sand.
Cooling in a furnace heated to between 600 ° C and 650 ° C is effective.
Especially for high quality blade steel and cutting tools, apply slow cooling after forging.
It is also effective in preventing the cracking of blade steel.