Nano-Structured Steel Forgings

C.C. Chen, E.Y. Chen
Transition45 Technologies, Inc., US

Keywords: steel, nano-structure, forgings, high strength

Summary:

This work demonstrates the performance and properties benefits that could be derived through the fabrication of bulk structural steel forgings with nano-scale structures through an innovative forging approach. Forge processing is a method of thermo-mechanical processing (TMP) for producing structural components with controlled microstructure-properties. The actual forge product often involves a massive volume containing various rib-and-web shapes, thicknesses, and sizes, and the feasibility of developing a uniform grained structural part cannot be done through a simple experimental and/or conventional forging approach. In an actual manufacturing practice, only current conventional forging equipment and process can provide a process-simplicity flexibility and economics for production feasibility and manufacturing applicability of NG/UFG- and fine grained (FG) forgings. Some advantages of the process/technology described here include process simplicity, flexibility, controllability, and affordability. Results to date have achieved nano-structured steel forging strength increases of ~35 to 45% compared with conventionally processed hot-forged materials. Fine grain forge processing can also increase the as-forged strength by ~50 to 70% compared with material heat treated using conventional methods, with comparable toughness values. These properties improvements offer the unique opportunity of fabricating higher performance, relatively inexpensive nano-steel structural components and tools for the most demanding oil and gas applications.