Influence of niobium on the structure and properties of the matrix of high-speed steel with nickel

2016 ◽  
Vol 1 (6) ◽  
pp. 57-62
Author(s):  
Jerzy Pacyna
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Structure And Properties ◽  
The Matrix

scholarly journals Improving Properties of Tool Steels by Method of Dynamic Alloying

2019 ◽  
Vol 18 (5) ◽  
pp. 369-379
Author(s):  
A. S. Kalinichenko ◽  
V. I. Ovchinnikov ◽  
S. M. Usherenko ◽  
Javad F. Yazdani-Cherati
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
Matrix Material ◽  
Amorphous State ◽  
High Speed Steel ◽  
Deep Penetration ◽  
Structure And Properties ◽  
Tool Steels ◽  
Particle Flows ◽  
Dynamic Processing

The influence of high-speed particle fluxes on changes in the structure and properties of materials has been widely studied currently. The effect exerted by particles moving at very high speeds can have both negative (in spacecrafts) and positive character (dynamic processing of tool steels). Therefore a task for studying an effect of high-speed particle flows on structure change in tool steels and improving their performance properties has been set in the paper. The study has used an explosive method for creation of a high-speed flow of SiC + Ni and Al2O3 particles. Samples after dynamic alloying have been subjected to diffusion nitriding. Microstructure of specimens made of X12M, R18, R6M5K5steel has been studied using optical and electron metallography. Wear resistance of the samples has been also tested on a friction machine. Theoretical and experimental results on a complex effect of high-speed microparticle flows and nitriding on a structure and properties of tool steels have been obtained during the research. It has been established that dynamic alloying by particles leads to formation of a specific structure in a composite material reinforced with channels. Central fiber (channel) zone with powder particles residues is surrounded by areas of amorphous state which is succeeded by a zone with a nanocrystalline fragmented cellular structure. Then we observe a zone with a microcrystalline structure that transits to a zone with crystalline structure which is characteristic for a matrix material of structural steel. The obtained data can expand and complement some ideas about mechanisms for dynamic loading of solids and condensed matter, plastic deformation, physical mechanics of structurally inhomogeneous media at different levels, a number of effects arising from collision and ultra-deep penetration of microparticles into metals. It has been shown that wear resistance of high-speed steel subjected to dynamic alloying in the quenched state is increased by 1.2 times in comparison with wear resistance of steel alloyed in the annealing state.

Relationship Between Alloy Composition and Tool-Life of High-Speed Steel Twist Drills

1992 ◽  
Vol 114 (4) ◽  
pp. 459-464 ◽  
Author(s):  
W. E. Henderer
Keyword(s):  
Tool Life ◽  
High Speed ◽  
Alloy Composition ◽  
High Speed Steel ◽  
Vanadium Content ◽  
The Matrix ◽  
Life Tests ◽  
And Performance ◽  
Twist Drills ◽  
The Relationship

Tool-life tests are reported which show the relationship between the alloy composition of high-speed steel twist drills and performance. Tool-life is shown to depend primarily on the composition of the matrix consisting of tempered martensite and precipitated secondary carbides. The longest tool-life was obtained from alloys with high vanadium content and low tungsten or molybdenum content. This observation is consistent with the dispersion characteristics of vanadium carbide which precipitate during tempering.

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.

An EM study of carbides in double austenitized AISI M2 high-speed steel

1990 ◽  
Vol 48 (4) ◽  
pp. 908-909
Author(s):  
Bilgehan Ögel ◽  
Erdoĝan Tekin
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
X Ray ◽  
Heat Treated ◽  
Conventional Heat Treatment ◽  
Fine Carbide ◽  
The Matrix ◽  
Carbide Distribution ◽  
M2 High Speed Steel ◽  
Diamond Paste

Multiple austenitization is not a conventional heat treatment process in tool steel industry and has only recently attracted some attention. Several workers who studied multiple austenitized high speed steels reported a fine carbide precipitation in the matrix of double austenitized specimens. However, the metallography of this precipitation is not well documented and needs further investigation. In this study, the microstructure of AISI M2 high speed steel and the effect of double austenitization on carbide distribution is investigated using SEM.The heat treated specimens were prepared by conventional metallographic methods for SEM examination. Polishing with diamond paste gave better results as much less carbides were extracted from their sites. Picral was used as an etchant.It is known that in M2 steels, undissolved carbides are either M6C or MC type. However, in the present investigation some of the massive undissolved M6C carbides contained small dark regions within them (Fig.l). X-ray mapping for W, Mo and V of such a carbide has shown that it is mainly a M6C carbide,whereas the dark regions on it is rich in vanadium implying that these regions represent V4C3 (Fig.2).

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