close grain

• 细晶粒

close grain的用法和样例：

例句

1. The methods to obtain ultrafine grain in new generation steel were investigated.
   探索了在新一代钢中获得超细晶粒的方法。
2. The microstructure and fine structure of weld fusion zone for high strength fine grain steel were studied.
   研究了高强度细晶粒碳素钢焊接接头熔合区附近的显微组织及精细结构。