Article ID Journal Published Year Pages File Type
5455372 Materials Science and Engineering: A 2017 10 Pages PDF
Abstract
Modern surface hardening processes intend among other to induce compressive residual stresses in the near-surface layers of the part. During subsequent tempering, these stresses can affect the phase transformations. Dilatometric tempering experiments starting from martensitic AISI 4140 were performed with a uniaxial compressive stress that simulates the compressive residual stresses mentioned above. An unexpected strain drop, increasing with the applied stress, was measured. It is argued that this effect is due to transformation induced plasticity caused by the Greenwood-Johnson effect. For an applied compressive stress of 358MPa, a strain decrease of 0.6% occurs which means that this has imperatively to be taken into account when tempering a hardened surface with compressive residual stresses.
Related Topics
Physical Sciences and Engineering Materials Science Materials Science (General)
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