coarse martensite

例句：

1. 1.The coarse martensite structure of the steel is due to the high cooling rate during solidification.
   这种钢的粗粒马氏体结构是由于凝固过程中冷却速率过高造成的。
2. 2. The coarse martensite phase in the alloy has a lower melting point and higher hardness than the finer phase.
   合金中的粗粒马氏相具有较低的熔点和较高的硬度，而细粒相则相反。
3. 3. Coarse martensite is more brittle and prone to cracking compared to finer phases.
   与更细的相相比，粗粒马氏体更脆，更容易产生裂纹。