"steel that has a case depth of .080 @ Rc65 minimum"
Question:
"Here's my problem. My teacher has given us an assignment. The Problem is to come up with a steel (choice being; low carbon, alloy, or plain carbon steel, our choices do not include tool steel or stainless steels) that has a case depth of .080 @ Rc65 minimum. My selection must also achieve maxium wearability in severe impact and sliding abrasion applications. I have narrowed my selections down to (2) choices a 41 series or a 86 series steeel, the reason I have choosen these two is for the additions of nickel, chromium, and molybdenum. My questions to you: how to figure out if i will have maxium wear and impact resistance in the steels I have choosen, how much room in temp. is now allowed due to the introduction of the alloys(temp. to reach full austenite), will the alloys affect quench and cool time, how to figure out if the steel will have a case depth of .080 @ Rc65."
Answer:
The two alloy series that you have considered are good initial choices. As to the specifics of your questions, wear resistance generally increases with increasing hardness. The complication to this simple relationship, is that at similar hardness, the alloy with the greater carbon content and hardest carbides (tungsten carbide) will possess the greatest wear resistance. There are many books published by ASM http://www.asm.org that contain heat treating information for low alloy steels. As to the case hardness and depth issue, most heat treaters know from experience how to obtain a specific case carbon content and depth. The needed results are verified by testing.