straight carbon steel

例句：

1. 1.This new car uses straight carbon steel for its body parts.
   这款新车使用直碳钢作为其车身部件。
2. 2. The construction of the bridge was made with straight carbon steel.
   这座桥梁的建设使用了直碳钢。
3. 3. The engineer used straight carbon steel to make the machine stronger and more durable.
   工程师使用直碳钢制作了这台机器，使其更强壮、更耐用。