Interfacial Behavior of Dissimilar Friction Welded Nodular Cast Irons with Low Carbon Steels

Welding of dissimilar materials is frequently accompanied by structural and technological difficulties and not always successful. The knowledge resulting from dissimilar welding experiments can be used to further identify directions and suitable technological parameters for optimal results. This paper report on the difficulties encountered on friction welding of nodular cast irons with low alloyed steels, due in principle to the low deformation capacity and the microstructural differences. It was shown through experiments that low friction times and high axial pressure leads to a significant plastifiation of the cast iron, while the low alloyed steel remains practically undeformed. The early (premature) plastifiation of the cast iron leads to a radial expulsion of the base structure associated with a continuous transport of the graphite nodules in the joint plan. As a result, a new graphite film forms which hinders a metallic contact between the parts and a welded joint. Qualitative and quantitative electron microscopy observations reveal carbon and alloying elements diffusion phenomena on the interface of the dissimilar materials to be joined.

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Corrosion Behavior of Carbon Steels Under Tuff Repository Environmental Conditions

MRS Proceedings ◽

10.1557/proc-44-287 ◽

1984 ◽

Vol 44 ◽

Author(s):

R. Daniel McCright ◽

H. Weiss

Keyword(s):

Stress Corrosion ◽

Carbon Steels ◽

Saturated Steam ◽

Nuclear Waste Repository ◽

Well Water ◽

General Corrosion ◽

Low Carbon ◽

Cast Irons ◽

J 13 ◽

Alloy Steels

AbstractCarbon steels may be used for borehole liners in a potential high-level nuclear waste repository in tuff in Nevada. Borehole liners are needed to facilitate emplacement of the waste packages and to facilitate retrieval of the packages, if required. Corrosion rates of low carbon structural steels AISI 1020 and ASTM A-36 were determined in J-13 well water and in saturated steam at 100°C. J-13 well water is representative of water which has percolated through the tuff horizon where the repository would be located. Tests were conducted in air-sparged J-13 water to attain stronger oxidizing conditions. A limited number of irradiation corrosion and stress corrosion tests were performed. Chromium-molybdenum alloy steels and cast irons were also tested. These materials showed lower general corrosion but were susceptible to stress corrosion cracking when welded.

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Researches on the Diffusion Phenomena in the Thermo-Chemical Treatment of Oxy-nitrocarburizing of Some Grey Cast Irons

Revista de Chimie ◽

10.37358/rc.18.12.6751 ◽

2019 ◽

Vol 69 (12) ◽

pp. 3367-3371 ◽

Cited By ~ 1

Author(s):

Gina Mihaela Sicoe

Keyword(s):

Cast Iron ◽

Chemical Composition ◽

Chemical Treatment ◽

White Layer ◽

Carbon Equivalent ◽

Chemical Compositions ◽

Nitrogen Diffusion ◽

Cast Irons ◽

Diffusion Phenomena ◽

Grey Cast

The thermo-chemical treatment of oxy-nitrocarburizing consists in the enrichment of materials in C, N and O in order to improve the physico-mechanical properties and the use of the materials. This leads to the increase in exploitation life, the increase of wear resistance, galling, corrosion, and slight erosion. The research presented in this article followed the study of the application of this treatment and the results obtained on pearlitic grey cast iron with different chemical compositions, domain in which there are few experimental results published. The results obtained on a number of 10 samples, presented in the article, highlighted the good compatibility of these materials with the thermo-chemical treatment of oxy-nitrocarburizing, obtaining on the surface some white layers which give good anti-corrosive properties, similar to those obtained on steel. There was no correlation between the depth of the white layer and the chemical composition of the studied cast iron. It was also emphasized that the depth of nitrogen diffusion is influenced by the chemical composition of the studied materials which is directly proportional to carbon equivalent (Ceq) of cast iron.

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On the Influence of Temperature upon the Magnetic Properties of a Graded Series of Carbon Steels

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s037016460002530x ◽

1912 ◽

Vol 31 ◽

pp. 505-516

Author(s):

Margaret B. Moir

Keyword(s):

Magnetic Properties ◽

Cast Iron ◽

Test Specimen ◽

Low Carbon Steel ◽

Carbon Steels ◽

Temperature Curve ◽

Maximum Point ◽

Low Carbon ◽

Influence Of Temperature ◽

Susceptibility Curve

Summary1. Experiments of Hopkinson, Curie, and D. K. Morris.2. Precautions necessary in magnetic testing. If the temperature of a test-specimen is changed, the specimen must be rendered neutral at the new temperature previous to carrying out the test.3. The effect of increasing the temperature of a specimen of cast iron from 15° C. to 190° C. is to improve its magnetic quality for moderate values of the magnetising force; from 190° C. to 260° C. the magnetic quality falls off, after which there is a further improvement. Finally the specimen becomes non-magnetic at the critical temperature. These results indicate the presence of a transformation point for carbon alloys of iron in the neighbourhood of 200° C.4. Steel containing 1·64 per cent, of carbon resembles cast iron in its behaviour. The set-back in magnetic quality takes place at much the same temperature as that which occurs in cast iron, the magnitude of the set-back being much the same for both.5. Steel containing 0·8 per cent, of carbon exhibits the transformation point, but in a less marked degree. The first maximum point in the susceptibility curve occurs at 180° C, and the first minimum point at 220° C.6. Low carbon steel containing 0·3 per cent, of carbon shows the transformation point; it is, however, very much less marked than in the case of the steels containing the higher percentages of carbon.7. The susceptibility-temperature curve of a specimen of soft iron containing 0·06 per cent, of carbon exhibits no turning points in the neighbourhood of 200° C. for fields lying between 2 and 15 c.g.s. units.

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Lattice Imaging of Twin, Lath and α/Martensite Boundaries in Duplex Low Carbon Steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100078195 ◽

1977 ◽

Vol 35 ◽

pp. 118-119

Author(s):

J. Y. Koo ◽

G. Thomas

Keyword(s):

High Resolution Electron Microscopy ◽

Ferrite Matrix ◽

Carbon Steels ◽

Bright Field Image ◽

Low Carbon ◽

Lattice Imaging ◽

Bright Field ◽

Lattice Image ◽

New Information ◽

Resolution Electron

High resolution electron microscopy has been shown to give new information on defects(1) and phase transformations in solids (2,3). In a continuing program of lattice fringe imaging of alloys, we have applied this technique to the martensitic transformation in steels in order to characterize the atomic environments near twin, lath and αmartensite boundaries. This paper describes current progress in this program.Figures A and B show lattice image and conventional bright field image of the same area of a duplex Fe/2Si/0.1C steel described elsewhere(4). The microstructure consists of internally twinned martensite (M) embedded in a ferrite matrix (F). Use of the 2-beam tilted illumination technique incorporating a twin reflection produced {110} fringes across the microtwins.

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Precipitation at the transformation interface of pearlite in steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177696 ◽

1990 ◽

Vol 48 (4) ◽

pp. 912-913

Author(s):

F. A. Khalid ◽

D. V. Edmonds

Keyword(s):

Thin Foil ◽

Carbon Steels ◽

Model Alloy ◽

Low Carbon ◽

High Carbon ◽

Growth Interface ◽

Medium Carbon ◽

Interphase Precipitation ◽

Solution Treated ◽

Wide Range

The austenite/pearlite growth interface in a model alloy steel (Fe-1lMn-0.8C-0.5V nominal wt%) is being studied in an attempt to characterise the morphology and mechanism of VC precipitation at the growth interface. In this alloy pearlite nodules can be grown isothermally in austenite that remains stable at room temperature thus facilitating examination of the transformation interfaces. This study presents preliminary results of thin foil TEM of the precipitation of VC at the austenite/ferrite interface, which reaction, termed interphase precipitation, occurs in a number of low- carbon HSLA and microalloyed medium- and high- carbon steels. Some observations of interphase precipitation in microalloyed low- and medium- carbon commercial steels are also reported for comparison as this reaction can be responsible for a significant increase in strength in a wide range of commercial steels.The experimental alloy was made as 50 g argon arc melts using high purity materials and homogenised. Samples were solution treated at 1300 °C for 1 hr and WQ. Specimens were then solutionised at 1300 °C for 15 min. and isothermally transformed at 620 °C for 10-18hrs. and WQ. Specimens of microalloyed commercial steels were studied in either as-rolled or as- forged conditions. Detailed procedures of thin foil preparation for TEM are given elsewhere.

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