scholarly journals Internal Stresses in PVD Coated Tool Composites

2016 ◽  
Vol 61 (3) ◽  
pp. 1371-1378 ◽  
Author(s):  
A. Śliwa ◽  
J. Mikuła ◽  
K. Gołombek ◽  
W. Kwaśny ◽  
D. Pakuła
Keyword(s):  
Chemical Composition ◽  
Carbide Phase ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Functionally Graded ◽  
Internal Stresses ◽  
Surface Zone ◽  
The Core ◽  
The Matrix

Abstract The aim of work is the investigation of the internal stresses in PVD coated metal matrix composites (MMC). Sintered MMC substrate is composed of the matrix with the chemical composition corresponding to the high-speed steel, reinforced with the TiC type hard carbide phase. Functionally graded composition of MMC providing of high ductility characteristic of steel in the core zone as well as high hardness characteristic of cemented carbides in the surface zone. Internal stresses were determined with use of finite element method in ANSYS environment. The reason of undertaking the work is necessity of develop the research of internal stresses, occurring in the coating, as well as in the adhesion zone of coating and substrate, which makes it possible to draw valuable conclusions concerning engineering process of the advisable structure and chemical composition of coatings. The investigations were carried out on cutting tool’s models containing defined zones differing in chemical composition. Modelled materials were characteristic of chemical composition corresponding to the high-speed steel at the core, reinforced with the TiC type hard carbide phase with the growing fraction of these phases in the outward direction from the core to the surface, additionally coated with (Ti,Al)N or Ti(C,N) functionally graded PVD coatings. Results of determined internal stresses were compared with the results calculated using experimental X-ray sin2ψ method. It was demonstrated, that the presented model meets the initial criteria, which gives ground to the assumption about its utility for determining the stresses in coatings as well as in functionally graded sintered materials. The results of computer simulations correlate with the experimental results.

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

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.

Effect of niobium and austenitizing temperature on the microstructures and properties of spray-deposited AISI M3:2 high speed steel

2021 ◽  
Vol 119 (1) ◽  
pp. 102
Author(s):  
Hebin Wang ◽  
Da Hong ◽  
Longgang Hou ◽  
Li Shen ◽  
Ping Ou ◽  
...  
Keyword(s):  
High Temperature ◽  
Grain Boundaries ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Spray Forming ◽  
Precipitation Strengthening ◽  
Austenitizing Temperature ◽  
The Matrix ◽  
Red Hardness

The microstructure and properties of niobium-containing AISI M3:2 high speed steels (HSSs) fabricated by spray forming and traditional casting have been investigated. The results show that fine and uniformly-distributed grains without macrosegregation appeared in the as-deposited HSSs that differ from those of as-cast HSSs. Nb mostly appears in primary MC carbides, whereas it contributes less to the formation of M6C carbides. The high stabilization of Nb-rich MC carbides can pin the grain boundaries during high-temperature austenitizing process, thus conferring a fine grains and raising the content of dissolved alloying elements. Enhanced precipitation strengthening and fine dispersion of NbC carbides throughout the matrix contribute to the high hardness and red hardness of Nb-containing HSS.

An Overview of the Microstructures Present in High-Speed Steel -Carbides Crystallography

2006 ◽  
Vol 530-531 ◽  
pp. 48-52 ◽  
Author(s):  
M.M. Serna ◽  
Edilson Rosa Barbarosa Jesus ◽  
E. Galego ◽  
Luís Gallego Martinez ◽  
H.P.S. Corrêa ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
First Principles ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Spray Forming ◽  
Steel Matrix ◽  
X Ray Diffraction ◽  
X Ray

The aim of the work was to prepare an overview about the microstructures present in high-speed steel, focused on the crystallography of the carbides. High-speed steels are currently obtained by casting, powder metallurgy and more recently spray forming. High-speed steels have a high hardness resulting from a microstructure, which consists of a steel matrix (martensite and ferrite), in which embedded carbides of different crystal structure, chemical composition, morphology and size, exist. These carbides are commonly named MxC, where M represents one or more metallic atoms. These carbides can be identified by X-ray diffraction considering M as a unique metallic atom. In this work, it is discussed, in basis of the first principles of physics crystallography, the validation of this identification when it is considered that other atoms in the structure are substitutional. Further, it is discussed some requirements for data acquisition that allows the Rietveld refinement to be applied on carbide crystallography and phase amount determination.

Effect of Carbon on Frictional Wear Behaviours of High Vanadium High Speed Steel under Dry Sliding Condition

2010 ◽  
Vol 654-656 ◽  
pp. 370-373 ◽  
Author(s):  
Liu Jie Xu ◽  
Shi Zhong Wei ◽  
Ying Ping Ji ◽  
Guo Shang Zhang ◽  
Ji Wen Li ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Carbon Content ◽  
High Speed ◽  
Lath Martensite ◽  
Strong Support ◽  
High Speed Steel ◽  
High Hardness ◽  
Micro Cutting ◽  
Matrix Microstructure ◽  
The Matrix

The high vanadium high-speed steel (HVHSS) with about 9wt% vanadium and different carbon contents were prepared using casting process. The effects of carbon on wear properties of HVHSS were studied using pin-on-ring tester, and the failure behaviors were investigated via SEM. Results show the optimal wear resistance is obtained when HVHSS possesses moderate carbon content (2.58wt.%). The cause is that the matrix microstructure of moderate carbon HVHSS is mainly low-carbon lath martensite with good toughness and high hardness, and it can effectively resist micro-cutting and figure wear at the same time, so the role of high-hardness vanadium carbides (VC) can be played enough because of the strong support of matrix. If carbon content is too low, the wear failure of HVHSS is mainly caused by severe micro-cutting and adhesive wear on contact surface because the matrix microstructure of high speed steel is ferrite with very low hardness, which leads to poor wear resistance. While, the matrix microstructure is mainly composed of high carbon martensite with poor toughness when carbon content is too high, therefore, it possesses very poor resistance to cycle fatigue and thermal fatigue, resulting in decrease of wear resistance.

CPM REX 25

Alloy Digest ◽  
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.

TATMO V-N

Alloy Digest ◽  
1985 ◽  
Vol 34 (12) ◽  
Keyword(s):  
High Speed ◽  
Cutting Tool ◽  
High Speed Steel ◽  
High Hardness ◽  
Heat Treating ◽  
Nitrogen Addition ◽  
Aisi Type ◽  
End Mills ◽  
Red Hardness ◽  
Edge Toughness

Abstract TATMO V-N is an AISI Type M7 high-speed steel modified by alloy balancing and a nitrogen addition to develop superior hardness response in heat treatment. It is an excellent grade for many cutting-tool applications requiring an optimum balance of red hardness, edge toughness and wear resistance, such as drills, taps, end mills, reamers and milling cutters. Its combination of outstanding properties and high hardness makes Tatmo V-N a logical alternate for cobalt high-speed steels in many cutting-tool applications. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-452. Producer or source: Latrobe Steel Company.

scholarly journals Effect of Deep Cryogenic Treatment on Corrosion Properties of Various High-Speed Steels

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Jure Voglar ◽  
Živa Novak ◽  
Patricia Jovičević-Klug ◽  
Bojan Podgornik ◽  
Tadeja Kosec
Keyword(s):  
High Speed ◽  
Cryogenic Treatment ◽  
Test Procedure ◽  
High Speed Steel ◽  
High Hardness ◽  
Polarization Measurement ◽  
Deep Cryogenic Treatment ◽  
Corrosion Properties ◽  
Potential Measurement ◽  
Corrosion Studies

The aim of the study was to evaluate the corrosion properties of three different grades of high-speed steel following a heat treatment procedure involving deep cryogenic treatment after quenching and to investigate how these properties are connected to the microstructure and hardness of the material. The hardness of steels was measured, and microstructural properties were determined through observation of the metallographically prepared steels using scanning electron microscopy. These studies were complemented corrosion evaluation by the use of corrosion potential measurement and linear polarization measurement of steels in a sodium tetraborate buffer at pH 10. The results showed that the deep cryogenic procedure of high-speed steel changed the microstructure and consequently affected the hardness of the investigated steels to different extents, depending on their chemical composition. Corrosion studies have confirmed that some high-speed steels have improved corrosion properties after deep cryogenic treatment. The most important improvement in corrosion resistance was observed for deep cryogenically treated high-speed steel EN 1.3395 (M3:2) by 31% when hardened to high hardness values and by 116% under lower hardness conditions. The test procedure for differentiating corrosion properties of differently heat-treated tool steels was established alongside the investigation.

Hardening of Selective Laser Melted M2 Steel

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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