Transition in iron and carbon steels at ~ 450 ºC

2021 ◽  
pp. 190-200
Author(s):  
К.Ю. Шахназаров ◽  
А.В. Михайлов ◽  
Д.В. Цуканов
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Temperature Interval ◽  
Pure Iron ◽  
Carbon Steels ◽  
X Ray ◽  
Iron Platinum ◽  
Steel Properties

Вокруг интервала температур 400-500 °С сложилась любопытная ситуация. М.В. Белоус с соавторами в своей монографии «Превращение при отпуске стали» его просто не замечают в классификации четырех превращений при отпуске, хотя еще в 1925 г. П. Обергоффер, основываясь на минимуме при 400-500 °С термоЭДС пары железо-платина, писал: «Имеем ли мы здесь дело с дальнейшим превращениями в чистом железе, должны показать новые подробные исследования». В настоящей работе на основании анализа многочисленных литературных данных, а также собственных экспериментальных (металлографического исследования, рентгеноструктурного анализа, сопротивления «горячей» осадке на образцах из практически чистого железа (0,008% С)) сделана попытка обосновать превращение в железе при ~ 450 ºС. Признание превращения при данной температуре дает возможность прогнозирования аномалий свойств сталей (производного железа) на том или ином этапе термической обработки. There is a curious situation around the temperature interval of 400-500 °C. M.V. Belous and co-authors in their monograph «Transformation during tempering of steel» simply do not notice it in the classification of the four transformations during tempering, although back in 1925. P. Oberhoffer, based on a minimum at 400-500 °C of the thermo-EDC of iron-platinum pair, wrote: «Whether we are dealing here with further transformations in pure iron, should show new detailed research». In the present work based on the analysis of numerous literature data and our own experimental data (metallographic research, X-ray analysis, resistance of «hot» precipitation on practically pure iron samples (0.008% C)) we have made an attempt to prove the iron transformation at ~ 450 ºC. The recognition of transformation at this temperature makes it possible to predict anomalies of steel properties (iron derivatives) at a certain stage of heat treatment.

Recent Applications of XSA in Heat Treatment and Fatigue of Steels

1983 ◽  
Vol 27 ◽  
pp. 179-190
Author(s):  
E. Macherauch ◽  
B. Scholtes
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Experimental Work ◽  
Carbon Steels ◽  
X Ray ◽  
Lattice Strains ◽  
Heat Treated ◽  
Computer Controlled

This paper is intended to give an exemplary review of recent investigations performed in the X-ray laboratory of the Institut für Werkstoffkunde I of the Universität Karlsruhe, FRG, concerning particular problems of residual stresses of heat-treated and fatigued steels. The experimental work was mainly performed with computer-controlled Karlsruhe type ψ-diffractometers. If linear distributions of residual lattice strains occurred the sin2ψ-method was applied to determine residual stresses. The experiments were performed with plain carbon steels of 0.22 and 0.45 wt.-% carbon (German grade Ck 22 and Ck 45) and some low alloyed steels.

scholarly journals FORMATION OF NANOCRYSTAL STATE IN DETAILS OF CARBON STRUCURAL STEELS

2018 ◽  
pp. 113-118
Author(s):  
A. A. Andrushevich ◽  
G. I. Aniskovich ◽  
P L. Kantor ◽  
D. V. Kuchuk
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Mechanical Characteristics ◽  
Structural Steels ◽  
Carbon Steels ◽  
Agricultural Machinery ◽  
Working Bodies

The conditions of formation of the nanocrystal state of the structure in carbon steels are considered in the article. The methods of research and experimental data on the microstructural structure of the strengthened parts of the working bodies of agricultural machinery made from carbon steels of the lowered hardenability are given. It is shown that pulsed quenching and low tempering provides of steel products with fragmented nanocrystal structure of the martensite. Fragmentation of martensite grains in carbon structural steels during heat treatment of parts significantly increases their mechanical characteristics.

The Precipitation of Si in AlCuSi Thin Films

1973 ◽  
Vol 31 ◽  
pp. 34-35 ◽  
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.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

scholarly journals X-ray Determination of Compressive Residual Stresses in Spring Steel Generated by High-Speed Water Quenching

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1154
Author(s):  
Diego E. Lozano ◽  
George E. Totten ◽  
Yaneth Bedolla-Gil ◽  
Martha Guerrero-Mata ◽  
Marcel Carpio ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
High Speed ◽  
Spring Steel ◽  
X Ray Diffraction ◽  
Laboratory Equipment ◽  
X Ray ◽  
Water Chamber ◽  
Hardened Case ◽  
Compressive Residual Stresses

Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about −700 MPa were obtained.

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