Effect of Retained Austenite on the Fracture Toughness of Quenching and Partitioning (Q&amp;P)-Treated Sheet Steels

Wu, Riming; Li, Wei; Zhou, Shu; Zhong, Yong; Wang, Li; Jin, Xianglin

doi:10.1007/s11661-013-2113-0

Cited by 81 publications

(35 citation statements)

References 51 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The value of in the sample over-aged, with reverted austenite present in the microstructure, is the same as of the ultimate strength measured when tested without hydrogen. The presence of reverted austenite in the microstructure elevated significantly the fracture toughness increasing the value for crack propagation [32]. Table 2 shows mechanical properties of the material tested in air and in 0.6 M NaCl solution at -1.2 V SCE in addition to calculated parameters affected by HE.…”

Section: Ssrt and He Susceptibilitymentioning

confidence: 99%

Hydrogen embrittlement of ultra high strength 300 grade maraging steel

et al. 2015

View full text Add to dashboard Cite

Section: Ssrt and He Susceptibilitymentioning

confidence: 99%

Hydrogen embrittlement of ultra high strength 300 grade maraging steel

et al. 2015

View full text Add to dashboard Cite

“…Most of the existing investigations on TRIP steels mainly focus on improving the mechanical properties by adjusting the volume fraction ratio of ferrite to austenite, which can be achieved by controlling chemical compositions and/or heat treatment processes [15,16,17,18]. Only a handful of works have noted that excellent mechanical properties of TRIP steels can be obtained by controlling the morphology of austenite [19,20].…”

Section: Introductionmentioning

confidence: 99%

Effects of Intercritical Annealing Temperature on Mechanical Properties of Fe-7.9Mn-0.14Si-0.05Al-0.07C Steel

et al. 2014

View full text Add to dashboard Cite

A medium Mn steel has been designed to achieve an excellent combination of strength and ductility based on the TRIP (Transformation Induced Plasticity) concept for automotive applications. Following six passes of hot rolling at 850 °C, the Fe-7.9Mn-0.14Si-0.05Al-0.07C (wt.%) steel was warm-rolled at 630 °C for seven passes and subsequently air cooled to room temperature. The sample was subsequently intercritically annealed at various temperatures for 30 min to promote the reverse transformation of martensite into austenite. The obtained results show that the highest volume fraction of austenite is 39% for the sample annealed at 600 °C. This specimen exhibits a yield stress of 910 MPa and a high ultimate tensile stress of 1600 MPa, with an elongation-to-failure of 0.29 at a strain rate of 1 × 10−3/s. The enhanced work-hardening ability of the investigated steel is closely related to martensitic transformation and the interaction of dislocations. Especially, the alternate arrangement of acicular ferrite (soft phase) and ultrafine austenite lamellae (50–200 nm, strong and ductile phase) is the key factor contributing to the excellent combination of strength and ductility. On the other hand, the as-warm-rolled sample also exhibits the excellent combination of strength and ductility, with elongation-to-failure much higher than those annealed at temperatures above 630 °C.

show abstract

“…Reference [47] observed that the retained γ-austenite level linearly increased as the MS temperature decreased. Using Eq.…”

Section: Stability Of Retained Austenite In the Microstructurementioning

confidence: 99%

Prediction of solidification phases in Cr-Ni stainless steel alloys manufactured by laser based powder bed fusion process

Jacob¹

2018

View full text Add to dashboard Cite

The microstructure and strength of chromium-nickel (Cr-Ni) stainless steel alloy parts is highly dependent on the chemical composition of the material and the thermal cycling it experiences during each processing step. This is particularly true when utilizing a laser powder bed fusion (LPBF) process to create the part. LPBF is an additive manufacturing (AM) process that quickly scans a laser over thin layers of powder to melt and solidify the powder to create the part. This results in rapid heating and cooling of the material that is dependent on the processing conditions and part geometry. Consequently, it is necessary to understand how these heating and cooling rates affect the resulting material phases of the final part. Only then the manufacturer can have confidence that the part will perform as intended. The objective of the report is to provide LPBF users with the necessary background to develop processing conditions that will achieve their microstructural design objectives.This report outlines the established methods, using chemical-composition-based phase diagrams (Schäffler and DeLong diagrams), to predict the material microstructure of stainless steel weld metals and applies those methods to LPBF manufactured Cr-Ni stainless steel (S17-4 1 ). Predictions of the solidification phases in Cr-Ni stainless steel alloys, based on the ratio of the Cr and Ni equivalent, are shown. Incorporating these ratios into the phase solidification diagram helps to predict whether the solidification of a Cr-Ni stainless steel occurs in primary ferritic or austenitic phase. This approach also helps users to understand how the increased nitrogen content in additively manufactured S17-4 results in the greater retention of austenite compared to the same material produced by traditional methods. These diagrams can also inform the users about the stability of the retained austenite and its likelihood to decompose into other phases, such as martensite and cementite. In addition to outlining how phase solidification diagrams can help AM users better understand the material they produce, this report also compares results from literature describing microstructure of LPBF fabricated S17-4 with the predicted microstructure before and after different heat treatments. The report also shows that the fine columnar austenitic-martensitic-ferritic microstructure of as-manufactured S17-4 has changed into a predominant martensitic microstructure by a cryogenic treatment, resulting in an increase of hardness.Furthermore, results of mechanical property measurements on additively manufactured S17-4 from other research work are compared and discussed in the result section to explain possibilities of the material phase transformations during different heat treatments, which lead to changes in the mechanical material properties.

show abstract

Effect of Retained Austenite on the Fracture Toughness of Quenching and Partitioning (Q&P)-Treated Sheet Steels

Cited by 81 publications

References 51 publications

Hydrogen embrittlement of ultra high strength 300 grade maraging steel

Hydrogen embrittlement of ultra high strength 300 grade maraging steel

Effects of Intercritical Annealing Temperature on Mechanical Properties of Fe-7.9Mn-0.14Si-0.05Al-0.07C Steel

Prediction of solidification phases in Cr-Ni stainless steel alloys manufactured by laser based powder bed fusion process

Contact Info

Product

Resources

About