The effect of the subcritical heat treatment on the microstructure and properties of Fe-Cr-C-V alloys

Experimental results indicate that the volume fraction of the carbide phase, carbide size and distribution had an important influence on the wear resistance of Fe-CrC-V alloys under low-stress abrasion conditions. Besides, the martensitic or martensiteaustenitic matrix microstructure more adequately reinforced the M7C3 eutectic carbides, minimizing cracking and removal during wear, than did the austenitic matrix. The secondary carbides which precipitate in the matrix regions of high chromium iron also influence the abrasion behaviour. The results of fracture toughness tests show that the dynamic fracture toughness in Fe-Cr-C-V white cast irons is determined mainly by the properties of the matrix. The high chromium iron containing 1.19 wt.% V in the as-cast condition, showed the greater dynamic fracture toughness when compared to other experimental alloys. The higher fracture toughness was attributed to strengthening during fracture, since very fine secondary carbide particles were present mainly in an austenitic matrix. In heat treated Fe-Cr-C-V alloys with varying contents of vanadium, lower Kid values were obtained, compared with as-cast alloys.

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Iron-chromium-carbon-vanadium white cast irons: Microstructure and properties

Hemijska industrija ◽

10.2298/hemind130615064f ◽

2014 ◽

Vol 68 (4) ◽

pp. 413-427 ◽

Cited By ~ 16

Author(s):

Mirjana Filipovic

Keyword(s):

Fracture Toughness ◽

Strain Hardening ◽

Volume Fraction ◽

Dynamic Fracture Toughness ◽

M23c6 Carbide ◽

Cast Irons ◽

Repeated Impact ◽

Secondary Carbides ◽

The Matrix ◽

Microstructure Parameters

The as-cast microstructure of Fe-Cr-C-V white irons consists of M7C3 and vanadium rich M6C5 carbides in austenitic matrix. Vanadium changed the microstructure parameters of phase present in the structure of these alloys, including volume fraction, size and morphology. The degree of martensitic transformation also depended on the content of vanadium in the alloy. The volume fraction of the carbide phase, carbide size and distribution has an important influence on the wear resistance of Fe-Cr-C-V white irons under low-stress abrasion conditions. However, the dynamic fracture toughness of Fe-Cr-C-V irons is determined mainly by the properties of the matrix. The austenite is more effective in this respect than martensite. Since the austenite in these alloys contained very fine M23C6 carbide particles, higher fracture toughness was attributed to a strengthening of the austenite during fracture. Besides, the secondary carbides which precipitate in the matrix regions also influence the abrasion behaviour. By increasing the matrix strength through a dispersion hardening effect, the fine secondary carbides can increase the mechanical support of the carbides. Deformation and appropriate strain hardening occur in the retained austenite of Fe-Cr-C-V alloys under repeated impact loading. The particles of precipitated M23C6 secondary carbides disturb dislocations movement and contribute to increase the effects of strain hardening in Fe-Cr-C-V white irons.

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Mechanical Analysis of Low and High Chromium Steels Used in Hot Strip Work Rolls

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.279.3 ◽

2018 ◽

Vol 279 ◽

pp. 3-9

Author(s):

Fethi Benkhenafou ◽

Ines Fernández Pariente ◽

F.Javier Belzunce ◽

Abdelkader Ziadi ◽

Ming Quan Shi ◽

...

Keyword(s):

Fracture Toughness ◽

High Speed ◽

Volume Fraction ◽

Research Work ◽

High Speed Steel ◽

Nodular Cast Iron ◽

High Chromium ◽

Eutectic Carbides ◽

Hot Strip ◽

Conventional Heat Treatment

Microstructure, hardness and fracture toughness of low and high chromium high speed steel used in hot strip mills and subjected to conventional heat treatment have been examined. The influence of tempering temperatures on the mechanical properties of these products, determined using tensile and fracture toughness tests, was studied in this research work. The developed microstructures have been characterized by XRD, optical microscopy and SEM examinations. Macrohardness and microhardness of the specimens have been evaluated by Vickers indentation technique. The fracture toughness of these products was investigated using the rupture weight on 3 points bending specimens. The plane strain fracture toughness KIc and the fracture strength were measured for each alloy. The shell is high harness high speed steels, and the core is nodular cast iron. It was found that most fracture occurred in the eutectic carbides formed by the high content alloy element, such as Mo,V,Cr, but that for the alloys with a reduced volume fraction of eutectic carbides, a small amount of crack propagation occurred in the austenitic dendrites.

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Characterization of Fracture Toughness of Hybrid MMCs the Short Fiber Reinforced Metal Matrix Composites

International Journal of Modern Physics B ◽

10.1142/s0217979203019733 ◽

2003 ◽

Vol 17 (08n09) ◽

pp. 1827-1832

Author(s):

Moon Sik Han ◽

Jung Il Song

Keyword(s):

Fracture Toughness ◽

Metal Matrix Composites ◽

Dynamic Fracture ◽

Metal Matrix ◽

Matrix Alloy ◽

Short Fiber ◽

Dynamic Fracture Toughness ◽

Matrix Composites ◽

Fiber Reinforced ◽

The Matrix

Evaluation of fracture toughness of short fiber reinforced metal matrix composites (MMCs) becomes important for the application as structural materials. Therefore, in this study static and dynamic fracture toughness of MMCs manufactured by squeeze casting process were investigated. A number of MMCs have been tested with various matrix alloys, volume fractions, and specifically types of reinforcements. It was found that static and dynamic fracture toughness of metal matrix composites was remarkably decreased by the addition of ceramic reinforcements. Dynamic fracture toughness slightly decreased compared with static fracture toughness because of the effect of dynamic velocity under impact loading. The toughness of ceramic reinforced MMCs is controlled by a complexity interaction between the matrix alloy and reinforcement. Important properties which influence toughness include the type of reinforcement (its physical form, size), volume fraction and combination of reinforcement, and the matrix alloy. And notch fracture toughness of MMCs for simple evaluation was also discussed.

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Abrasion Resistance of as-Cast High-Chromium Cast Iron

Scientific Proceedings Faculty of Mechanical Engineering ◽

10.2478/stu-2014-0013 ◽

2014 ◽

Vol 22 (1) ◽

pp. 75-80 ◽

Cited By ~ 2

Author(s):

Marcela Pokusová ◽

Igor Berta ◽

Ľubomír Šooš

Keyword(s):

Wear Resistance ◽

Abrasion Resistance ◽

Test Results ◽

Austenitic Matrix ◽

Cast Irons ◽

High Chromium ◽

High Chromium Cast Iron ◽

Heat Treated ◽

The Matrix ◽

Chromium Cast Iron

AbstractHigh chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.%) 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.

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Influence of Heat Treatment of High-Speed Steel on its Microstructure, Hardness and Fracture Toughness

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.592-593.680 ◽

2013 ◽

Vol 592-593 ◽

pp. 680-683

Author(s):

Franjo Cajner ◽

Vojteh Leskovšek ◽

Dragan Pustaić

Keyword(s):

Fracture Toughness ◽

High Speed ◽

Volume Fraction ◽

High Speed Steel ◽

Experimental Investigations ◽

Eutectic Carbides ◽

Microstructural Parameters ◽

Heat Treated ◽

The Matrix ◽

Steel Aisi

The correlation between fracture toughness, hardness and microstructure of vacuum heat-treated high-speed steel AISI M2 was investigated. Our intention was to investigate the influence of microstructural parameters such as the volume fraction of undissolved eutectic carbides, their mean diameter, the mean distance between the carbides, as well as the volume fraction of retained austenite in the matrix, on the above mentioned mechanical and fracture properties. The experimental investigations were performed on the high-speed steel. This steel had the following chemical composition (mass content in %): 0.89% C, 0.20% Si, 0.26% Mn, 0.027% P, 0.001% S, 3.91% Cr, 4.74% Mo, 1.74% V and 6.10% W.

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Viscoelastic Effect on the Fracture Toughness of GFRP: Experimental Approach

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.306-308.745 ◽

2006 ◽

Vol 306-308 ◽

pp. 745-750 ◽

Cited By ~ 2

Author(s):

Shirley Savet Lana ◽

Hiroomi Homma ◽

Kohji Nakazato

Keyword(s):

Fracture Toughness ◽

Dynamic Fracture ◽

Damage Zone ◽

Dynamic Fracture Toughness ◽

Glass Fiber Reinforced Plastic ◽

Glass Fiber Reinforced ◽

Reinforced Plastic ◽

Dynamic Fracture Tests ◽

The Matrix ◽

Static Fracture

The dynamic fracture tests were carried out for a glass fiber reinforced plastic specimen with a crack and dynamic fracture toughness was evaluated by examination of cracking at an initial slit root. Before the crack initiated at the slit root, a whitened damage zone was created surrounding the slit tip. The damage zone consists of micro cracking in the matrix, debonding between a fiber and the matrix, and fracture of the fiber. The comparison of the dynamic fracture toughness and the static fracture toughness value shows that the former is around 12 MPa√m and apparently higher than the later, which is 7 MPa√m. To understand those experimental results and mechanics of the damage zone, a dynamic debonding test was carried out and dynamic bonding strength was estimated as around 70 MPa.

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