TY - JOUR
T1 - The Dependence of Fracture Resistance on the Size and Distribution of Blocky Retained Austenite-Martensite Constituents
AU - Yang, Dezhen
AU - Xiong, Zhiping
N1 - Publisher Copyright:
© 2020, The Minerals, Metals & Materials Society and ASM International.
PY - 2020/5/1
Y1 - 2020/5/1
N2 - Although third-generation advanced high-strength steels have achieved a great combination of high ultimate tensile strength and ductility, edge cracking has been frequently reported during their cold forming of components. Following this issue, the effects of the stability, the morphology, and the amount of retained austenite (RA) on fracture resistance have already been investigated. However, the influence of the size and distribution of blocky RA and/or martensite (RA/M) islands on fracture resistance is absent, which is deliberately addressed in this study. After austenitization, the effect of holding temperatures between 278 °C and 400 °C on microstructure evolution in a Fe-0.3C-2.5Mn-1.5Si-0.8Cr (wt pct) steel is systematically and quantitatively investigated. Tensile properties and fracture resistance are characterized using uniaxial tension and double edge-notched tension tests, which interestingly show that an increased product of ultimate tensile strength and total elongation is accompanied with a decreased fracture resistance. This is because that tensile properties are mainly affected by the stability and amount of RA while the fracture resistance is also affected by the size and distribution of blocky RA/M islands. A coarse size of and a small interspacing between blocky RA/M islands are detrimental to the fracture resistance due to the promotion of crack nucleation and crack propagation.
AB - Although third-generation advanced high-strength steels have achieved a great combination of high ultimate tensile strength and ductility, edge cracking has been frequently reported during their cold forming of components. Following this issue, the effects of the stability, the morphology, and the amount of retained austenite (RA) on fracture resistance have already been investigated. However, the influence of the size and distribution of blocky RA and/or martensite (RA/M) islands on fracture resistance is absent, which is deliberately addressed in this study. After austenitization, the effect of holding temperatures between 278 °C and 400 °C on microstructure evolution in a Fe-0.3C-2.5Mn-1.5Si-0.8Cr (wt pct) steel is systematically and quantitatively investigated. Tensile properties and fracture resistance are characterized using uniaxial tension and double edge-notched tension tests, which interestingly show that an increased product of ultimate tensile strength and total elongation is accompanied with a decreased fracture resistance. This is because that tensile properties are mainly affected by the stability and amount of RA while the fracture resistance is also affected by the size and distribution of blocky RA/M islands. A coarse size of and a small interspacing between blocky RA/M islands are detrimental to the fracture resistance due to the promotion of crack nucleation and crack propagation.
UR - http://www.scopus.com/inward/record.url?scp=85081638374&partnerID=8YFLogxK
U2 - 10.1007/s11661-020-05698-0
DO - 10.1007/s11661-020-05698-0
M3 - Article
AN - SCOPUS:85081638374
SN - 1073-5623
VL - 51
SP - 2072
EP - 2083
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 5
ER -