The Effects of Heat Treatment on the Microstructure and Mechanical Properties of Nb-V Microalloyed Powder Metallurgy Steels

Türkmen, Mustafa; Erden, Mehmet Akif; Karabulut, Hasan; Gündüz, Süleyman

doi:10.12693/aphyspola.135.834

Cited by 16 publications

(17 citation statements)

References 4 publications

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“…They attributed this increase to the formation of precipitates such as NbC(N) and VC(N) during and after the sintering. He also determined that Nb-V microalloyed steel has better mechanical properties when sintered at 1350 • C [5,[14][15][16]. Furthermore, the yield point elongation of nonalloyed PM steels was longer than that of microalloyed PM steel.…”

Section: Resultsmentioning

confidence: 99%

“…The precipitates observed in alloys via SEM and EDS analyses are known to have important effects upon recrystallization and austenite grain growth [ 14 , 15 , 16 ]. The microalloying elements such as Nb and V precipitate as vanadium carbide (VC), vanadium nitrite (VN), vanadium carbonitride (VCN), niobium carbide (NbC), niobium nitrite (NbN) and niobium carbonitride (NbCN) during the hot rolling or sintering followed by cooling for PM process, contributing to the desired tensile and hardness strength of microalloyed steels by grain refinement, solid solution hardening and precipitation hardening mechanisms [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. When the average grain sizes of alloy 1 and alloy 2 are calculated, while the average grain size of alloy 1 was 36.8 µm, it could be seen that the average grain size of alloy 2 decreased to 30.5 µm due to forming precipitates such as VC(N) and NbC (N) during sintering.…”

Section: Resultsmentioning

confidence: 99%

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The Effect of Nickel on the Microstructure, Mechanical Properties and Corrosion Properties of Niobium–Vanadium Microalloyed Powder Metallurgy Steels

et al. 2020

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In this study, the effects of adding Ni in different ratios to Fe-matrix material containing C-Nb-V produced by powder metallurgy on microstructure, tensile strength, hardness and corrosion behaviors were investigated. Fe-C and Fe-C-Nb-V powders containing 5%, 10%, 13%, 15%, 20%, 30% and 40% nickel were pressed at 700 MPa and then sintered in an Ar atmosphere at 1400 °C. Microstructures of the samples were characterized with optical microscope, scanning electron microscope (SEM) and XRD. Corrosion behaviors were investigated by obtaining Tafel curves in an aqueous solution containing 3.5% NaCl. Mechanical properties were determined by hardness and tensile testing. While Fe-C alloy and Fe-C-Nb-V microalloyed steel without Ni typically have a ferrite-pearlite microstructure, the austenite phase has been observed in the microstructures of the alloys with 10% nickel and further. Yield and tensile strength increased with nickel content and reached the highest strength values with 13% Ni content. The addition of more nickel led to decrease the strength. Analysis of Tafel curves showed that corrosion resistance of alloys increased with increasing nickel concentration.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

The Effect of Nickel on the Microstructure, Mechanical Properties and Corrosion Properties of Niobium–Vanadium Microalloyed Powder Metallurgy Steels

et al. 2020

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“…In the addition of 4% and 5% Mo, a rise in number of pores and fall in the bainite phase was detected as a result of the excessive formation of MoC (N) deposits in the grain boundaries of Mo in the structure, and it is thought to affect the mechanical properties. Though porosity is not good for strength [14][15][16][17][18][19], the current study got small and spherical pores which are not adversarial to the strength of the current material. As seen in Table 3, the theoretical density before sintering, density and porosity after sintering were calculated.…”

Section: Microstructure and Mechanical Properties Of Mo-added Pm Steelmentioning

confidence: 76%

“…Despite the fact that the present steels are created as flat and tubular items, the making of forged steels has also accelerated in recent years. In addition, steel production is carried out by powder metallurgy method, although it is not sufficient today [14][15][16]. In the literature, there are some studies about PM steel production and microstructure mechanical property relationship.…”

Section: Introductionmentioning

confidence: 99%

Investigation of microstructure, mechanical and machinability properties of Mo-added steel produced by powder metallurgy method

Erden

Yaşar

Korkmaz

et al. 2021

Int J Adv Manuf Technol

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This study presents the impact of molybdenum (Mo) inclusion on microstructure, mechanical, and machinability behavior of steels manufactured with powder metallurgy (PM) approach. PM steel samples with different molybdenum ratios were pressed at 750-MPa pressing pressure and sintered in the atmosphere-controlled tube furnace at 1400°C for 1 h. While particle size and distribution of phases of PM steels with different molybdenum ratios were determined by optical microscope, mechanical properties were determined by applying tensile test. The results were observed that 3% Mo weight-added steel displayed the maximum yield and tensile strength. In addition, the machinability properties of 3% Mo-added steel, which has the highest yield and tensile strength, were investigated. In this work, we researched the thrust force and surface roughness as machinability output, and drilling parameters on the output were determined by utilizing analysis of variance. Finally, SEM images were taken from the inner surfaces of the machined holes and the fractured surfaces from tensile test, and information about the machinability of this alloy produced with PM was presented. As a result, an increase in yield and tensile strength and a reduction in strain were identified with the increase in Mo content. Moreover, the coated cutting tools are better on the machining output than the uncoated cutting tools in terms of green environment. The most important factors on the Fz and Ra are the coating condition and the feed rate with 56.53% and 43.62% PCR, respectively.

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“…porosity is one of the important parameters that directly affect mechanical properties. To reduce porosity in powder metal steels, changing the pressing technique such as warm-hot pressing and bidirectional pressing, changing the sintering parameters such as increasing the sintering temperature, extending the sintering time, applying different thermal processes and increasing the pressing pressure [2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

A New Heat Treatment Cycle Design for High Wear Resistant in PM Steels

Altuntaş

Güral

2020

International Journal of Automotive Science and Technology

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In this study, 1.5% by weight of natural graphite powders were added to Atomet 1001 pure iron powders and unalloyed high carbon powder metallurgy steel specimens were obtained. After the mixture was uniaxial pressed at room temper-ature and 700 Mpa pressing pressure, it was sintered in Ar protected atmosphere controlled oven at 1150 ° C for 20 minutes. The densities of the specimens before and after sintering were measured using precision scales and electronic calipers and presented graphically. After sintering, microstructure specimens containing primary cementite and typical dense perlite colonies were produced. The sintered specimens having primary cementite plus lamellar pearlitic structures were fully quenched from 950 °C temperature and then over-tempered at 705 °C temperature for 60 minutes to produce spherical-fine cementite particles in the ferritic matrix. After by this treatment, these specimens annealed at 735 °C temperature for 3 minutes were austempered at 300 °C salt bath for a period of 1 to 5 hours. After the heat treatment, dry sliding wear tests of specimens were carried out under 10N constant load and 500-1500m wear distance. At the end of the dry sliding wear test, the weight losses of the specimens were measured and it was determined that the dry sliding wear resistance increased with increasing austempering time after spheroidization annealing.

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The Effects of Heat Treatment on the Microstructure and Mechanical Properties of Nb-V Microalloyed Powder Metallurgy Steels

Cited by 16 publications

References 4 publications

The Effect of Nickel on the Microstructure, Mechanical Properties and Corrosion Properties of Niobium–Vanadium Microalloyed Powder Metallurgy Steels

The Effect of Nickel on the Microstructure, Mechanical Properties and Corrosion Properties of Niobium–Vanadium Microalloyed Powder Metallurgy Steels

Investigation of microstructure, mechanical and machinability properties of Mo-added steel produced by powder metallurgy method

A New Heat Treatment Cycle Design for High Wear Resistant in PM Steels

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