Go outside and grab the assault rifle from the dead slave by the door. This should last you for most of the steelyard if you are even a half decent shot. Try to save some of it for the upcoming fights though, especially if you aren't going to collect the ingots and get the better weapons from the Mill Worker quest. Also, if you have 75 points in Science, hack the terminal by the supply plant and activate the four protectrons. They will kill a lot of the trogs and establish a safe zone in the train yard. You can find this turret right around the first corner near the entrance to the supply plant. You should be able to easily see the Protectrons.

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I personally suggest you just go ahead and raid the supply plant. It's next to the entrance, lightly guarded, and there are 18 ingots inside. They are fairly concentrated too. Just go in, kill the few trogs and wildmen, hack the few turrets to your advantage, and come back out. You can also just collect the few easy stashes by the train cars. There are 4 in the dumpsters, 2 in the right corner past the supply plant, 2 in the little storage house at the top of the stairs, and 2 in the alley near that storage house. Easy enough if you can kill the first batch of trogs without wasting too much ammo. If any of this confusing, then just skip ahead to my guide for the "Mill Worker" quest. I'll have full details for every stash in there.
Once you have 10 ingots, backtrack out of the steelyard. The abandoned area isn't as safe, since the first trog you saw on the walkway into the steelyard has broken through the cage. Just shoot him. If you want, you can grab another 3 ingots in a mining cart located off of the main path. Give Everett the ingots to get a new slave outfit and report back to Midea. Collecting 10 steel ingots also earns you the “Auto Axpert” perk, even if you didn't use one the entire time.