Heat Treatment Optimisation of Supersolidus Sintered Steel Compounds

The aim of this work was the study of the heat treatment optimisation of high chrome steels used for the manufacture of rolling rolls in order to obtain a final product with a high hardness and wear resistance and taking into account the very large dimensions typical of these products. The effect of modifying the maintenance temperature and time during the different phases of the heat treatment on the microstructure and hardness of this product was evaluated. The necessity of adjusting the temperature and maintenance time of the quenching heat treatment in order to obtain a martensitic/bainitic matrix with a low austenite content followed by two tempering treatments was demonstrated as the best way to obtain the optimal properties of the product for this particular application.

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The Effects of Post-Sintering Treatments on Microstructure and Mechanical Properties of Mn-Mo Steel

Powder Metallurgy Progress ◽

10.1515/pmp-2017-0011 ◽

2017 ◽

Vol 17 (2) ◽

pp. 104-111

Author(s):

Ch. Fiał

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Tensile Strength ◽

Sintered Steel ◽

Sintering Atmosphere ◽

Closed Container ◽

Single Action ◽

Different Types ◽

Strength And Plasticity ◽

Additional Tempering

Abstract The effect of heat treatment on density, hardness, microstructure and tensile properties of Fe-0.85Mo-1.3Mn-0.6C sintered steel were investigated. Pre-alloyed Astaloy 85Mo, ferromanganese and UF4 graphite powders were mixed for 60 minutes in a Turbula mixer and then pressed in single-action die at 660MPa to produce green compacts (according to PN EN ISO 2740).The compacts were sintered in a specially designed semi-closed container at 1120 or 1250°C for 60 minutes in N2. The chemical composition of the sintering atmosphere was modified by adding getter and/or activator into the container. Two different types of heat treatment in nitrogen were carried out: sinteraustempering at 525°C for 60 minutes; and sinterhardening with additional tempering at 200°C for 60 minutes. The slightly better combination of strength and plasticity of steel for both sintering temperatures were achieved after sinterhardening+tempering variant. Average values of 0.2% offset yield stress, ultimate tensile strength and elongation after sintering in 1250°C, were 415MPa, 700MPa, and 2.0%, respectively.

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The Precipitation of Si in AlCuSi Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070618 ◽

1973 ◽

Vol 31 ◽

pp. 34-35 ◽

Cited By ~ 1

Author(s):

R. M. Anderson

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Heat Treatment ◽

Solid Solution ◽

Integrated Circuit ◽

Copper Film ◽

Solution Concentration ◽

X Ray ◽

Silicon Thin Films ◽

Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

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The influence of heat treatment on the fiber/matrix interface in a SiC-reinforced glassceramic

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105771 ◽

1988 ◽

Vol 46 ◽

pp. 742-743

Author(s):

E. Bischoff ◽

O. Sbaizero

Keyword(s):

Heat Treatment ◽

Aluminum Silicate ◽

Lithium Aluminum ◽

Interfacial Region ◽

Specimen Preparation ◽

Crack Wake ◽

Pull Out ◽

Annealed Material ◽

Ultrasonic Drilling ◽

Fiber Matrix Interface

Fiber or whisker reinforced ceramics show improved toughness and strength. Bridging by intact fibers in the crack wake and fiber pull-out after failure contribute to the additional toughness. These processes are strongly influenced by the sliding and debonding resistance of the interfacial region. The present study examines the interface in a laminated 0/90 composite consisting of SiC (Nicalon) fibers in a lithium-aluminum-silicate (LAS) glass-ceramic matrix. The material shows systematic changes in sliding resistance upon heat treatment.As-processed samples were annealed in air at 800 °C for 2, 4, 8, 16 and 100 h, and for comparison, in helium at 800 °C for 4 h. TEM specimen preparation of as processed and annealed material was performed with special care by cutting along directions having the fibers normal and parallel to the section plane, ultrasonic drilling, dimpling to 100 pm and final ionthinning. The specimen were lightly coated with Carbon and examined in an analytical TEM operated at 200 kV.

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Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087331 ◽

1991 ◽

Vol 49 ◽

pp. 604-605

Author(s):

A.H. Advani ◽

L.E. Murr ◽

D. Matlock

Keyword(s):

Heat Treatment ◽

Grain Boundary ◽

Stress Corrosion Cracking ◽

Stainless Steels ◽

Deformation Twin ◽

Austenitic Stainless Steels ◽

Carbide Precipitation ◽

Strain Induced Martensite ◽

Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

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Effect of a Complex Heat Treatment on the Structure of 300M Steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098071 ◽

1981 ◽

Vol 39 ◽

pp. 312-313

Author(s):

R. Padmanabhan ◽

W. E. Wood

Keyword(s):

Heat Treatment ◽

Metal Carbides ◽

Austenite Grain Size ◽

300M Steel ◽

Heat Treated ◽

Strain Fracture ◽

Prior Austenite Grain Size ◽

Short Time ◽

Final Tempering ◽

Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

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Crystallization of MgO • Al2 • SiO2 • ZrO2 glasses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143778 ◽

1986 ◽

Vol 44 ◽

pp. 440-441

Author(s):

M. A. McCoy

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Powder Processing ◽

Glass Composition ◽

Ceramic Powder ◽

Transformation Toughening ◽

Ceramic Powder Processing ◽

Processing Techniques ◽

Ceramic Matrices

Transformation toughening by ZrO2 inclusions in various ceramic matrices has led to improved mechanical properties in these materials. Although the processing of these materials usually involves standard ceramic powder processing techniques, an alternate method of producing ZrO2 particles involves the devtrification of a ZrO2-containing glass. In this study the effects of glass composition (ZrO2 concentration) and heat treatment on the morphology of the crystallization products in a MgO•Al2•SiO2•ZrO2 glass was investigated.

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