適切な金型の選び方と金型ロスのケース

Mold selection
Die Material Selection is a very important link in the whole die making process. 金型材料の選択は 3 つの原則を満たす必要があります, 耐摩耗性を満たすために金型を作成する, 強度と靭性およびその他の作業要件, プロセス要件を満たすためにダイ, そして金型は経済的適用性を満たさなければなりません. 折り畳む条件に必要なものは、
1. 耐摩耗性. When the blank is plastically denatured in the die cavity, it flows and slides along the surface of the die cavity, causing severe friction between the die cavity surface and the blank, which leads to the failure of the die due to wear. したがって, the wear resistance of the material is one of the most basic and important properties of the die. Hardness is the main factor affecting wear resistance. 一般に, the higher the hardness of the die parts, the smaller the wear amount, the better the wear resistance. 加えて, wear resistance is also related to the type, amount, 形, size and distribution of carbides in the material.
2. Strong toughness, die working conditions are mostly very bad, some often bear a larger impact load, resulting in brittle fracture. In order to prevent die parts in the work of sudden brittle fracture, die should have high strength and toughness. The toughness of the die mainly depends on the carbon content, grain size and microstructure of the material.
3. Fatigue fracture performance, die work in the long-term effect of cyclic stress, often lead to fatigue fracture. Its forms include low-energy repeated impact fatigue fracture, tensile fatigue fracture, contact fatigue fracture and bending fatigue fracture. The fatigue and fracture properties of the die mainly depend on its strength, toughness, hardness, and the content of inclusions in the material.
4. High temperature performance, when the working temperature of the mold is higher, will reduce the hardness and strength, leading to mold early wear or plastic deformation and failure. したがって, the mold material should have high anti-tempering stability, in order to ensure that the mold in the working temperature, with a higher hardness and strength.
5. Resistance to cold and hot fatigue. Some dies are heated and cooled repeatedly in the working process, which makes the surface of

The die cavity subject to tension and pressure strain stress, causes surface cracking and spalling, increases friction, and hinders plastic deformation, reduced Dimensional accuracy, resulting in mold failure. Cold and hot fatigue is one of the main failure forms of hot working dies, and this kind of dies should have high cold and hot fatigue resistance. 6. Corrosion resistance, some molds such as plastic mold in the work, because of the presence of chlorine, fluorine and other elements in plastic, heat after decomposition out HCI, HF and other strong corrosive gas, erosion mold cavity surface, increase its Surface roughness, increase wear failure.
1) The material of the main working parts of the mold is improperly selected. The material has poor performance and is not wear-resistant; the die steel has not been refined and has a large number of smelting defects; the convex and concave molds, forging blanks and the forging process are not perfect, and there are hidden dangers of heat treatment.

2) Die structure design problem, the die structure is unreasonable. The slender punch is not designed with a reinforcement device, the discharge port is not smooth and piles up, and the discharge force is too large, and the punch is subjected to increased alternating load.

3) PMMAはドライホッパーに保管する必要があります もう1つは、材料の加熱プロセス中に発生するさまざまなガスを除去することです。 making process is imperfect, これは主に凸型および凹型鍛造ブランクの内部品質の低下に現れます。, 熱処理技術とプロセスに問題がある, 凸型と凹型の焼き入れが不完全になる, 柔らかい部分と不均一な硬さ. 場合によっては、微小な亀裂やひび割れが発生することもあります, 研削と研磨が適切に行われていない, 表面粗さの値が大きすぎます.

4) 無潤滑または潤滑しても効果が悪い