Monitoring the Microstructural Evolution in Spheroidized Steels by Magnetic Barkhausen Noise Measurements

DAVUT K., GÜR C. H.

JOURNAL OF NONDESTRUCTIVE EVALUATION, vol.29, no.4, pp.241-247, 2010 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 29 Issue: 4
  • Publication Date: 2010
  • Doi Number: 10.1007/s10921-010-0082-4
  • Journal Name: JOURNAL OF NONDESTRUCTIVE EVALUATION
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.241-247
  • Keywords: Steel, Spheroidizing, Microstructure, Magnetic Barkhausen Noise, PEARLITE SPHEROIDIZATION, NONDESTRUCTIVE EVALUATION, FERROMAGNETIC MATERIALS, CARBON-STEELS, DEFORMATION, EMISSION, HARDNESS, IRON
  • Middle East Technical University Affiliated: Yes

Abstract

The aim of this study is to monitor nondestructively the degree of spheroidization in steels by Magnetic Barkhausen Noise (MBN) method. Various series of specimens consisting of either lamellar pearlite or partially/completely spheroidized carbides were produced from AISI 1060 steel by appropriate heat treatments. All specimens were characterized by metallographic examinations, hardness and MBN measurements. The results show that MBN signals are very sensitive to the variations in the microstructure caused by the spheroidizing heat treatment. The change of microstructure, from coarse lamellar carbides to uniformly dispersed spherical carbides in ferrite matrix, is reflected as higher Barkhausen activity due to less effective pinning of domain walls.