Fracture mechanism and model of 18Ni maraging steel

ABSTRACT

18Ni maraging steel is normally used to make key components by machining processes. It is necessary to understand the fracture mechanism and behaviour of 18Ni maraging steel for the study and further optimisation of machining processes. In this paper, the Split Hopkinson Tensile Bar tests accompanied by quasi-static mechanical tests are carried out to relate the stress triaxiality, deformation temperature and strain rate with the fracture strain. During the building up of the fracture model, it is noticed that the change of fracture mechanism from 600°C to 900°C brings about a non-linear relationship of fracture strain with the deformation temperature. This results in a large error in fitting the Johnson–Cook (J-C) fracture model, so a modified fracture model is put forward.

KEYWORDS:

• 18Ni maraging steel
• fracture mechanism
• fracture model
• non-linear relationship

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work is supported by the National Natural Science Foundation of China under Grant No. 51575051 and the Key Project of Science and Technology Research in Colleges and Universities of Hebei Province No. ZD2019025.