The results show that the pre-hardened plastic-mould steel belongs to a little low machinability steel because of much hard inclusion existing in microstructure and its high strength and hardness.

结果表明，这类材料属较难加工材料，这主要是由于钢中存在大量硬质点，且材料具有较高强度和硬度所致。

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One problem was that magnesium (Mg) combined with tin (Sn) during billet reheat, which resulted in low strength, such as tensile strength, and poor machinability.

一个问题是，在坯料再加热过程中镁(Mg)与锡(sn)结合，导致低的强度(例如拉伸强度)，以及差的机械加工性。

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High strength, low thermal conductivity, high ductility and high work hardening tendency of stainless steels are the main factors that make their machinability difficult.

不锈钢材料由于强度高、导热系数低、韧性大以及加工硬化严重等原因使得切削加工非常困难。

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