Influence of aging on the relaxation and internal friction properties of cold drawn pearute

Journal Article · Thu Nov 01 04:00:00 EST 1984 · Scr. Metall.; (United States)

DOI:https://doi.org/10.1016/0036-9748(84)90129-7· OSTI ID:6462459

Ravera, P P; Colombo, R L; Firrao, D

Rolled wire of eutectoid steel containing approximately 0.8% carbon is particularly suitable for hardening by cold drawing. When drawn it acquires exceptional mechanical strength, so that it can transform int the strongest material known, apart from the thinnest metal wiskers. Lamellar pearlite is obtained by isothermally annealing (patenting) austenite at temperatures between 720 and 450/sup 0/ C, the interlamellar spacing being a decreasing function of the transformation temperature. The strength of a patented wire cold drawn to a given reduction has been the subject of almost exhaustive studies of Embury and Fischer, later re-interpreted by Langford, in terms of a modified Petch argument. Drawn pearlitic wires are used as a reinforcement in pre-stressed concrete, and, under the name of ''music wire'', to make springs. Under these conditions, the mechanical strength, though important, is not the most interesting property, which is, instead, the capacity to show a small load (or stress) relaxation rate under constant extension. The relaxation will be called parabolic, logarithmic or hyperbolic. Usually the three alternatives take place successively in the course of a sufficiently long relaxation test. It has to be appreciated that a relaxation test is similar in many respects, but by no means identical, to a low temperature creep test. The work done up to 1970 in the entire field of microplasticity of steel wires has been extensively reviewed by Lehnert.

• Research Organization: Dipartimento di Scienza dei Materiali Instituta Chimica Politecnico di Torino, Torino
• OSTI ID: 6462459
• Journal Information: Scr. Metall.; (United States), Journal Name: Scr. Metall.; (United States) Vol. 18:11; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360103* -- Metals & Alloys-- Mechanical Properties
AGE HARDENING
AGING
COLD WORKING
CREEP
DESTRUCTIVE TESTING
DRAWING
FABRICATION
FRICTION
HARDENING
INTERNAL FRICTION
MATERIALS TESTING
MATERIALS WORKING
MECHANICAL PROPERTIES
PEARLITE
PLASTICITY
RELAXATION
STRESS RELAXATION
TESTING
WIRES