"passive iron" meaning in English

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  "lang_code": "en",
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      "glosses": [
        "Iron that has been subjected to the action of heat, strong nitric acid, chlorine, etc. It is then not easily acted upon by acids."
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          "nitric acid",
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          "chlorine",
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        "(chemistry) Iron that has been subjected to the action of heat, strong nitric acid, chlorine, etc. It is then not easily acted upon by acids."
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  "word": "passive iron"
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        "Iron that has been subjected to the action of heat, strong nitric acid, chlorine, etc. It is then not easily acted upon by acids."
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        "(chemistry) Iron that has been subjected to the action of heat, strong nitric acid, chlorine, etc. It is then not easily acted upon by acids."
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  "word": "passive iron"
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