Influence of Heat Treatment on Content of the Carbide Phases in the Microstructure of High-Speed Steel

Abstract This article presents the results of investigations of the effect of heat treatment temperature on the content of the carbide phase of HS3-1-2 and HS6-5-2 low-alloy high-speed steel. Analysis of the phase composition of carbides is carried out using the diffraction method. It is determined that with increasing austenitising temperature, the intensification of dissolution of M6C carbide increases. As a result, an increase in the grain size of the austenite and the amount of retained austenite causes a significant reduction in the hardness of hardened steel HS3-1-2 to be observed. The results of diffraction investigations showed that M7C3 carbides containing mainly Cr and Fe carbides and M6C carbides containing mainly Mo and W carbides are dissolved during austenitisation. During austenitisation of HS3-1-2 steel, the silicon is transferred from the matrix to carbides, thus replacing carbide-forming elements. An increase in a degree of tempering leads to intensification of carbide separation and this process reduce the grindability of tested steels.

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Effects of modification on microstructure and properties of Al-bearing high-boron high-speed steel

Metallurgical Research & Technology ◽

10.1051/metal/2018126 ◽

2018 ◽

Vol 116 (1) ◽

pp. 108

Author(s):

Zhang Yaguang ◽

Hanguang Fu ◽

Lin Jian ◽

Wang Changan ◽

Lei Yongping

Keyword(s):

Heat Treatment ◽

High Speed ◽

High Speed Steel ◽

High Hardness ◽

Impact Testing ◽

Wear Testing ◽

Microstructure And Properties ◽

Different Types ◽

The Matrix ◽

High Boron

The microstructure of Al-bearing high-boron high speed steel (AB-HSS) contains a large amount of borocarbides, which makes it have high hardness, superior wear resistance and thermal stability. But the borocarbides are coarser and continuously distribute along the grain boundary which seriously destroys the toughness of AB-HSS. In this paper, the microstructure and properties of AB-HSS were regulated by adding modifiers and quenching and tempering heat-treatment. The modifier was RE-Mg, Ti and N elements. The microstructure and properties of AB-HSS were investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), the electron probe microanalysis (EPMA), hardness testing, wear testing, and impact testing. The results show that the borocarbides in as-cast AB-HSS are found in intergranular networks showing different degrees of continuity after adding different types of modifiers. The matrix of as-cast AB-HSS all is composed of ferrite, pearlite and martensite, and the borocarbides all consist of M2(B,C) and M7(C,B)3 after adding different types of modifiers. After high-temperature heat treatment, the borocarbides in the microstructure of RE-Mg modification AB-HSS appear as discontinuous networks showing signs of spheroidization and the distribution of the borocarbides is more uniform. The matrix of RE-Mg modification AB-HSS is martensite and the borocarbides consist of M2(B,C), M7(C,B)3 and M23(C,B)6. The hardness of RE-Mg modification AB-HSS reaches 61.7 HRC, and impact toughness increases by 52%, and has excellent comprehensive mechanical properties.

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Sintered Valve Seat Inserts – Microstructural Characterisation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.530-531.65 ◽

2006 ◽

Vol 530-531 ◽

pp. 65-70 ◽

Cited By ~ 3

Author(s):

E.S. Jesus Filho ◽

Edilson Rosa Barbarosa Jesus ◽

Lucio Salgado ◽

S.L. Jesus ◽

Marco Antonio Colosio ◽

...

Keyword(s):

Heat Treatment ◽

High Speed ◽

Diffusion Mechanism ◽

High Speed Steel ◽

Heat Treatment Condition ◽

Commercial Application ◽

Valve Seat ◽

Before And After ◽

The Matrix ◽

Valve Seat Inserts

This work presents aspects related to new sintered materials for valve seat inserts application. Two types of materials were evaluated. The materials were made using powder metallurgy technique from a basic mixture of high-speed steel (AISI M3/2), iron and carbide powders. The microstructures of these materials before and after heat treatment are presented. Under the heat treatment condition, the activation of the diffusion mechanism among phases was promoted and a better distribution of the Cu phases along the matrix was achieved. The results indicate that the materials under development have a potential for commercial application as valve seat inserts.

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Effects of Heat Treatment Temperature on Microstructure and Mechanical Properties of M2 High-Speed Steel Selective Laser Melting Samples

10.20944/preprints202005.0246.v1 ◽

2020 ◽

Author(s):

Huan Ding ◽

Xiong Xiang ◽

Rutie Liu ◽

Jie Xu

Keyword(s):

Heat Treatment ◽

Flexural Strength ◽

Selective Laser Melting ◽

Heat Treatment Temperature ◽

High Speed ◽

High Speed Steel ◽

Treatment Temperature ◽

Laser Melting ◽

Average Value ◽

M2 High Speed Steel

At different heat treatment temperatures, the hardness and flexural strength of M2 high-speed steel selective laser melting (SLM) parts show mixed trends. When the heat treatment temperature is 260°C, the hardness and flexural strength of the M2 high-speed steel SLM part are decreased, but the hardness difference between the upper and lower surfaces of the M2 high-speed steel SLM part is also reduced. When the heat treatment temperature is 560°C, the hardness and flexural strength of the M2 high-speed steel SLM part are almost close to that of the original M2 high-speed steel SLM part, and the performance gradient in the sample is improved, and the overall structure is uniform. When the subsequent heat treatment temperature is 860 °C, the hardness of the SLM parts reaches a minimum, with an average value of 24 HRC. However, the flexural strength exceeds that of the original SLM parts. Moreover, the microstructure of the sample is uniform, which significantly improves the anisotropy of performance.

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Research on Frictional Wear Property of the High Vanadium High Speed Steel in Conditions of Low Slip-Roll Ratio

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.455.431 ◽

2010 ◽

Vol 455 ◽

pp. 431-434

Author(s):

Hui Min Chen ◽

L.J. Xu ◽

H.G. Wang

Keyword(s):

Carbon Content ◽

Retained Austenite ◽

High Speed ◽

Testing Machine ◽

High Speed Steel ◽

Frictional Resistance ◽

Wear Testing ◽

Wear Property ◽

The Matrix ◽

The Impact

The frictional resistance and abrasion mechanism of high vanadium high speed steel were studied by the self-made friction wear testing machine under the conditions of 0.5% slip-roll ratio. Results show that the frictional resistance increases with the increase of carbon content. The retained austenite and the shapes of carbides will change when the carbon content alters, which make the frictional resistance of the material change, and the proper quantities of retained austenite makes the impact toughness the matrix better; The spherical VC can prevent the initiation and expansion of cracks forming and make the frictional resistance increase. The abrasion mechanism is fatigue flake under the condition of rolling and sliding.

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Study on Frictional Wear Property of the High Vanadium High Speed Steel

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.458.252 ◽

2010 ◽

Vol 458 ◽

pp. 252-257 ◽

Cited By ~ 1

Author(s):

Hui Min Chen ◽

Liu Jie Xu

Keyword(s):

Carbon Content ◽

Retained Austenite ◽

High Speed ◽

Testing Machine ◽

High Speed Steel ◽

Frictional Resistance ◽

Wear Testing ◽

Wear Property ◽

Frictional Wear ◽

The Matrix

The frictional resistance and abrasion mechanism of high vanadium high speed steel were studied by the self-made friction wear testing machine under the conditions of 10% slip-roll ratio. Results show that the frictional resistance increases with the increase of carbon content and is optimal when the carbon content is 2.92%. The carbon content affect the wear resistance by changing the amount of the retained austenite and the shapes of carbides, the moderate quantities of retained austenite makes the matrix have better impact toughness and hardness; The spherical VC can prevent the initiation and expansion of cracks forming and make the frictional resistance increase. The abrasion mechanism is fatigue flake under the condition of rolling and sliding.

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UNS T12001

Alloy Digest ◽

10.31399/asm.ad.ts0495 ◽

1989 ◽

Vol 38 (1) ◽

Keyword(s):

Heat Treatment ◽

Physical Properties ◽

Tool Steel ◽

High Speed ◽

High Speed Steel ◽

Heat Treating ◽

General Purpose ◽

Steel Mills

Abstract UNS T12001 is a general-purpose, tungsten, high-speed steel containing nominally 18% tungsten, 4% chromium and 1% vanadium. It is suitable for practically all high-speed applications. This steel has been the standard of the industry for many years because of its cutting ability, ease of heat treatment and minimum tendency to decarburize. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, and machining. Filing Code: TS-495. Producer or source: Tool steel mills.

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CPM REX 25

Alloy Digest ◽

10.31399/asm.ad.ts0365 ◽

1980 ◽

Vol 29 (7) ◽

Keyword(s):

Heat Treatment ◽

High Speed ◽

High Speed Steel ◽

High Hardness ◽

Heat Treating ◽

High Speeds ◽

Aisi Type ◽

Tool Performance ◽

End Mills ◽

Machining Operations

Abstract CPM REX 25 is a super high-speed steel made without cobalt. It is comparable to AISI Type T15 cobalt-containing high-speed steel in response to heat treatment, properties, and tool performance. CPM REX 25 is recommended for machining operations requiring heavy cuts, high speeds and feeds, and difficult-to-machine materials of high hardness and abrasion resistance. Typical applications are boring tools, drills, gear cutters, punches, form tools, end mills and broaches. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-365. Producer or source: Crucible Materials Corporation.

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Hardening of Selective Laser Melted M2 Steel

10.31399/asm.cp.ht2021p0007 ◽

2021 ◽

Author(s):

Mei Yang ◽

Yishu Zhang ◽

Haoxing You ◽

Richard Smith ◽

Richard D. Sisson

Keyword(s):

Heat Treatment ◽

High Speed ◽

Cutting Tools ◽

High Speed Steel ◽

High Hardness ◽

Steel Part ◽

X Ray Diffraction ◽

X Ray ◽

Heat Treated ◽

Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

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