point hardening

例句：

1. 1. The steel was subjected to point hardening treatment to improve its strength.
   钢材经过点硬化处理以提高其强度。
2. 2.During the manufacturing process, the material undergoes point hardening treatment to enhance its durability.
   在制造过程中，材料会经历点硬化处理以增强其耐用性。
3. 3. The engineers used point hardening technology to create a stronger and more durable product.
   工程师们利用点硬化技术制造出更坚固耐用的产品。