Testing for a passive surface is usually accomplished by looking for traces of free iron on the metal surface.

钝化表面的检测通常是通过查看金属表面的游离铁的踪迹来完成的。

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Testing for a passive surface is usually accomplished by looking for traces of free iron on the metal surface.

钝化表面的检测通常是通过查看金属表面的游离铁的踪迹来完成的。

youdao