Okay, the user wants me to translate "steel city" into Traditional Chinese. Let me check the rules again. The first rule says to translate all content into Traditional Chinese. The second rule states that if the content is already in Traditional Chinese, leave it as is. The third rule is to provide only the translation without any explanations.
So, "steel city" is in English. I need to translate it. The direct translation would be "鋼鐵城市". Let me confirm that "steel" is "鋼鐵" and "city" is "城市" in Traditional Chinese. Yes, that's correct. There's no need to adjust anything else here. The user didn't mention any specific context that might change the translation. So the answer should be "鋼鐵城市".