Cast iron manhole cover of good quality is to see its toughness and hardness.
质量好的铸铁井盖是要看其韧度和硬度的。
2
To reheat hardened steel or hardened cast iron to some temperature below the eutectoid temperature for the purpose of decreasing hardness and increasing toughness.
重新加热硬化钢或硬化铸铁至某一温度，低于共析温度下，使硬度降低，韧度增加。
3
The results show that the range of austenitizing temperature required for bainite hardening and the hardness of bainite ductile cast iron is increased as vanadium is added.