Influence of Boron on Austenite to Ferrite Transformation Behavior of Low Carbon Steel Under Continuous Cooling

Koley, Soumyajit; Karani, Arnab; Chatterjee, Soumya; Shome, Mahadev

doi:10.1007/s11665-018-3459-7

Cited by 10 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Alloying is an essential tool to design and engineer new materials with optimized properties. For decades, boron (B), for instance, has been added to several classes of steels to improve its hardenability [1][2][3][4][5][6]. It is added to steels between 10 to 30 ppm to optimize ultimate tensile strength and toughness.…”

Section: Propertiesmentioning

confidence: 99%

“…When added to steels up to this limit, boron segregates to austenite grain boundaries (AGBs), reducing the grain boundary energy and increasing the hardenability by suppressing the nucleation of allotriomorphic ferrite [7]. Due to the boron's high affinity with N and C, higher amounts of boron may induce boron nitrides or boron carbides at the AGBs, acting as nucleation sites for ferrite at high temperatures [5]. In addition, steels containing B are less susceptible to distortion and quenching cracking during heat treatments [8].…”

Section: Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Synergism between B and Nb improves fire resistance in microalloyed steels

Ferreira¹,

Carvalho²,

Ariza-Echeverri³

et al. 2022

Preprint

View full text Add to dashboard Cite

The development of new fire-resistant steels represents a challenge in materials science and engineering of utmost importance. Alloying elements such as Nb and Mo are generally used to improve the strength at both room-and high-temperatures due to, for example, the formation of precipitates and harder microconstituents. In this study we show alternatively that the addition of small amounts of boron in Nb-microalloyed steels may play a crucial role in maintaining the mechanical properties at high temperatures. The 66 % yield-strength criteria for fire resistance is achieved at ≈ 574 °C for a boron steel, whereas without boron this value reaches ≈ 460 °C, a remarkable boron-induced mechanical strengthening enhancement. DFT calculations show that boron additions can lower the vacancy formation energy when compared to pure ferrite and, for Nb-B steels, there is a further 24 % reduction, suggesting that the boron-niobium combination acts as an effective pinning-based strengthening agent.

show abstract

Section: Propertiesmentioning

confidence: 99%

Section: Propertiesmentioning

confidence: 99%

Synergism between B and Nb improves fire resistance in microalloyed steels

Ferreira¹,

Carvalho²,

Ariza-Echeverri³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…It has been reported that the positive effect of boron on hardenability is due to the separation of boron atoms at the austenite grain boundaries. [2][3][4][5][6]. The formation of these precipitates consumes boron atoms that dissociate at the austenite grain boundaries and the boron addition loses its beneficial effect on hardenability [7,8].…”

Section: Introduction (Gi̇ri̇ş)mentioning

confidence: 99%

Investigation of the Effect of Tempering and Cryogenic Treatment on Mechanical Properties of Boron Steels

ALTUNTAŞ,

KAPLAN,

BOSTAN

2023

Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım Ve Teknoloji

View full text Add to dashboard Cite

Boron steels are a group of steels that stand out with their high wear resistance and hardenability. In this study, 33MnCrB5-2 boron steel was shaped by applying hot forging process. After the hot forging process, the microstructure examinations and mechanical tests of the materials were carried out. A group of materials was cryogenically treated at -80 °C for 2 hours. Then, a different group of materials was austenitized at 890 °C and quenched, and then tempered at 400 °C for 90 minutes. In the last group of materials, after tempering heat treatment, cryogenic treatment was applied at -80 °C for 2 hours. Hardness and abrasion tests were carried out on the samples that were subjected to cryogenic treatment and tempering heat treatment. Microstructure analyzes were examined with the help of scanning electron microscope (SEM) and optical microscope. Element distributions from different regions in the microstructure were analyzed with energy-dispersive X-ray spectrometry (EDS). The crystallite size of the materials were calculated by X-ray diffraction. The results showed that the hardness value and wear resistance of the samples that were cryogenically treated after tempering gave higher values compared to the other samples.

show abstract

“…Alloying is essential for designing and engineering new materials with optimized properties. For decades, boron (B), for example, has been added to several classes of steels to improve its hardenability [1][2][3][4][5][6]. It is added to steels at between 10 to 30 ppm to optimize ultimate tensile strength and toughness.…”

Section: Introductionmentioning

confidence: 99%

“…When added to steels up to this limit, boron segregates to austenite grain boundaries (AGBs), reducing the grain boundary energy and increasing the hardenability by suppressing the nucleation of allotriomorphic ferrite [7]. Due to boron's high affinity with N and C, higher amounts of boron may induce boron nitrides or boron carbides at the AGBs, acting as nucleation sites for ferrite at high temperatures [5]. Costa et al [8] studied the effect of boron on quenched and tempered 39MnCrB6-2 steel and showed precipitation of boroncarbides at grain boundaries that embrittled the steel.…”

Section: Introductionmentioning

confidence: 99%

Synergism between B and Nb Improves Fire Resistance in Microalloyed Steels

Ferreira

Carvalho

Echeverri

et al. 2022

Metals

View full text Add to dashboard Cite

The long exposure of structural components to high temperatures (above 600 °C) negatively changes their mechanical properties, severely compromising the structural capacity of buildings and other structures in which safety is a primary concern. Developing new cheaper fire-resistant steels with better mechanical and thermal performances represents a challenging, cutting-edge materials science and engineering research topic. Alloying elements such as Nb and Mo are generally used to improve the strength at both room and high temperatures due to the formation of precipitates and harder microconstituents. This study shows that adding small amounts of boron in Nb-microalloyed fire-resistant steels may be crucial in maintaining mechanical properties at high temperatures. The widely used 66% yield-strength criteria for fire resistance was achieved at ≈574 °C for the B-added alloys. In contrast, for those without boron, this value reached ≈460 °C, representing a remarkable boron-induced mechanical strengthening enhancement. First-principles quantum mechanics calculations demonstrate that boron additions can lower 11.7% of the vacancy formation energy compared to pure ferrite. Furthermore, for Nb-added steels, the reduction in the vacancy formation energy may reach 33.2%, suggesting that the boron-niobium combination could act as an effective pinning-based steel-strengthening agent due to the formation of B-induced higher-density vacancy-related crystalline defects, as well as other well-known steel strengthening mechanisms reported in the literature. Adding boron and niobium may, therefore, be essential in designing better structural alloys.

show abstract

Influence of Boron on Austenite to Ferrite Transformation Behavior of Low Carbon Steel Under Continuous Cooling

Cited by 10 publications

References 21 publications

Synergism between B and Nb improves fire resistance in microalloyed steels

Synergism between B and Nb improves fire resistance in microalloyed steels

Investigation of the Effect of Tempering and Cryogenic Treatment on Mechanical Properties of Boron Steels

Synergism between B and Nb Improves Fire Resistance in Microalloyed Steels

Contact Info

Product

Resources

About