A perspective in the understanding of strength–toughness combination during processing of engineering ferrous alloys

ABSTRACT

The perspective presented here underscores the part played by grain size, grain boundary chemistry and substructural features such as martensite lath and packet size in determining the fracture toughness of high strength iron-based metallic materials. Each of these features influences the degree of plasticity. The notion of grain boundary segregation isotherms and thermodynamics related to the systems is explained, along with the effects on toughness of segregation of alloying elements to grain boundaries in complex alloy systems, specifically precipitation hardened ferrous alloys and maraging steels. The extensive review of experimental metal processing technology has provided a means of analysing the relationship of toughness to microstructural features. Important instances include maraging steels, precipitation hardened stainless steels, low alloy steels, interstitial-free steels, and microalloyed steels.

KEYWORDS:

• Processing
• strength–toughness
• concepts
• perspective

Acknowledgments

The author gratefully acknowledges several students, post-doctoral scholars, friends, colleagues, and their respective institutions with whom the author interacted and collaborated in the work presented here as an overview. Many of them have directly or indirectly contributed and spearheaded the work described here as an overview. In view of a long list of contributors and participants, the author preferred to defer the listing. Every attempt was made to cite relevant references to the described work and any omission is unintentional, particularly when only selected articles were considered during the preparation of the overview. Furthermore, it is pertinent to mention that the present article is brief or succinct overview with a focus on highlighting the salient aspects that are important in the context of strength–ductility–toughness combination.

Disclosure statement

No potential conflict of interest was reported by the author.

Data availability statement

Given that it is an overview article, data availability is not relevant. The author has done his best in citing the relevant articles. However, inadvertently there may be a situation where an article has not been appropriately cited. All figures adapted from references and reference numbers are indicated in the figure caption.