If I hadn't put you back in that oven for the second time, you wouldn't be kept for very long because the hardness would not have held.
如果我没有再次把你放进烤箱，你也不会被保存很长时间，因为硬度会消失。
2
The hardening case depth and hardness curve can be changed by adjusting heating time, heating power and cooling speed during induction hardening.
在感应淬火中，通过改变加热时间、加热功率和冷却速度可以改变淬硬层深度和硬度梯度。
3
At the same time, some of the same or higher hardness material, such as diamond, corundum, metal oxide, quartz crystals are likely to damage the material.