Associate professor, Rensselaer Polytechnic Institute, Troy, N. Y.
Pages: 32 Published: Jan 1980
A comprehensive review of the factors fundamental to ferritic stainless steel toughness has been undertaken. Emphasis has been placed on the micromechanisms of fracture and their effects on the ductile-to-brittle transition consistent with the Cottrell crack nucleation model. The general effects of strain rate, plastic constraint (including gage effect), and grain size are set forth. The basic fracture behavior of body-centered-cubic metals, iron and iron-chromium solid solutions, is summarized. Primary emphasis is placed on the role of second phases in the ferritic stainless steel fracture process, and carbides, nitrides, martensite, α'-precipitation, and σ- and χ-phases are discussed extensively. The role of titanium and columbium as gettering agents for carbon and nitrogen is considered. The effects of cold-work are set forth and a brief outline is made of annealing guidelines for optimized toughness. Finally, the fracture behavior of welds and weld heat-affected zones is discussed and approaches to improved as-welded toughness are reviewed.
toughness, fracture, stainless steel, microstructure, ferritic stainless steels, fracture toughness
Paper ID: STP38200S