My name is Tom and I’ve recently picked up the hobby at age 50, yep you read that right at age 50… I had made my own forge out of one of those little Joe grills, and coating the inside with fire brick mortar… and used a air pump for inflating mattresses. It was fun to build and managed to heat and turn a railroad spike into a bar… I know oooooh how impressive right??? Well I got to thinking the other day that I can use it to make knives and order so 15N20… now would I make a half way decent knife by using this and a railroad spike??? Thanks
Tom
Hey welcome Tom! I’ve seen some folks in their late 60s pick up blacksmithing, so 50 isn’t all that bad 
Sure you can use 15N20 with the railroad spike! A few things to consider though is that most railroad spikes that I have come across have been low carbon steel, which means it won’t hold an edge. When you laminate in the 15n20 you’ll be able to hold an edge on the 15n20 but the mild steel won’t, so you might get variable hardness to the blade.
If you were thinking of just inserting 15n20 into the railroad and having the 15n20 be the entire blade length then yeah that would work fine! I think there is a knife maker named Andy Alm’s Knives, I believe he often forge welds carbon steel onto railroad spikes. He makes some really nice looking knives, look him up.
Looking forward to talking with you more,
Grant