Exploring New Strategies for Ultrahigh Strength Steel via Tailoring the Precipitates

Jialong Tian,Zhouhua Jiang

doi:10.3389/fmats.2021.797798

Abstract

Ultrahigh-strength (UHS) steels have shown great potential in the field of high-end equipment manufacturing in demand of lightweight engineering and performance upgrade. A significant research effort has been directed toward the development of advanced UHS steels with excellent combination of strength and toughness. In the course of development, tailoring precipitates by means of composition design and process optimization is absolutely a critical module. In this mini review, typical UHS steels strengthened by carbides and intermetallics are systematically summarized and discussed. With the increase of strength, the toughness losses of UHS steels strengthened by carbides and intermetallics have been compared in detail. In particular, the in-depth mechanisms leading to various strength/toughness variation trends have been discussed, extracting the bottleneck in developing new-generation UHS steels containing merely one type of precipitate. Meanwhile, prospects on designing advanced UHS steels strengthened by coexisting dispersive precipitates have been proposed to achieve better performance.

Highlights

Ultrahigh-strength (UHS) steels, which exhibit ultimate tensile strength above 1,300 MPa, are widely used in the most challenging structural applications, such as aircraft landing gear, rocket cases, high-performance shafts and rings, and other critical sectors (Jeckins et al, 1993; Wanhill et al, 2017)
The present review aims in retrospect at the development of UHS steels with superior strength/toughness combinations and accounting for the most recent developments in this area
We focus on the fundamental role of precipitates in achieving desirable properties of UHS steels and evaluate our current understanding on the intrinsic interactions between composition designing–precipitate features–properties

Summary

INTRODUCTION

Ultrahigh-strength (UHS) steels, which exhibit ultimate tensile strength above 1,300 MPa, are widely used in the most challenging structural applications, such as aircraft landing gear, rocket cases, high-performance shafts and rings, and other critical sectors (Jeckins et al, 1993; Wanhill et al, 2017). Three basic classes of UHS steels won out in the multi-property selection process to become key competitors for UHS steel applications: i) High-strength low-alloy (HSLA) steel: 300M (contains 0.4%C, generally used for firstgeneration aircraft landing gear) (Youngblood et al, 1977), M50 (contains 0.8%C, widely applied to second-generation aircraft bearing) (Rydel et al, 2017); ii) Maraging steels: Custom 465 (famous high-strength stainless steel) (Daymond et al, 2016), 18Ni (strongest UHS with acceptable ductility and toughness) (Wang, B. et al, 2017), PH 13-8Mo (well-known high-strength stainless steel) (Leitner et al, 2011); iii) Co–Ni secondary hardening steels: Aermet 100 (used for second-generation aircraft landing gear) (Wang, L. et al, 2005), Ferrium S53 (developed for manufacturing advanced aircraft landing gear serviced in a marine environment) (Kuehmann et al, 2008)

C Cr Ni Co Mo Ti Al Cu Mn Si W V Precipitates

DISCUSSION