Can fire melt steel?
Fire can not melt anything directly. Instead, the process of "burning" create a lot of heat, heat which makes the molecules that compose the heated object oscilate faster, thus increasing the rejection forces between their nuclae, so solid objects end up behaving like liquids.
However, each composition reacts differently to heat, but considering steel is not something that occurs naturally, it must have been created somewhere. The temperature at which it melts is the same temperature at which it was created. And yes, you can achive that by using fire, but it depends what you are burning. Read more about how steel is created here.
