existent corrosion的用法和样例：
例句
- Differences in corrosion performance, however, depend heavily on the severity of the corrosion environment.
分歧在腐蚀的性能，但是，在很大程度上取决于严重程度的腐蚀环境。 - Underthe actions of corrosion and stress,the micro-cracks can be developed and then caused bust ofthe pipe.
腐蚀坑底形成大量微裂纹，在腐蚀和应力的共同作用下裂纹快速扩展导致断裂。
