Translation of "Gefügebestandteile" in English

Si and SiC containing as well as heavily Al-containing structure components occur.

The compositions of the different structure components were determined by micro-probe analyses.

Si and SiC containing as well as heavily Al-containing structure components occur.

In this way, ferritic and martensitic structure portions in the surface zone are changed to austenite.

As structure constituents of the natural-hard steel one finds ferrite, Perlit and Zementit.

This is possible only when the structural components are capable of diffusion or migration.

In the process the wear-resistant structural components such as iron carbide or ledeburite are constituted as crystals in the cast iron.

The mechanical properties and the microstructure constituents of the hot strips produced in accordance with the invention are reported in table 3.

This includes the structure components ferrite, bainite and in particular martensite and carbide in different morphologies.

Only then is it possible to recognize potentially unfavorable microstructural components on all size scales and derive suitable corrective measures.

When these steels were welded, sulphur-induced cracking susceptibility was high, and the heat affected zones contained high hardness microstructures susceptible to hydrogeninduced cold cracking.

The invention relates to a nickle/iron casting alloy, containing no cobalt, exhibiting high strength at elevated temperatures accompanied by insensitivity to thermal fatigue, possessing microstructural constituents which are thermodynamically highly stable, and exhibiting, in addition, high hardness at elevated temperatures, outstanding resistance to oxidation, corrosion and wear, as well as good welding properties, this alloy being particularly suitable as a material for nuclear reactor components.

To produce ceramic shaped articles having especially good strength properties, it has proven advantageous to use a high proportion of eutectic microstructural constituents.

However, for more complicated structural forms, it is important that the rate of cooling of the ceramic shaped article, and thus, the formation of the eutectic microstructural constituents, be regulated to achieve high homogeneity in the spacing of the individual zirconium oxide crystallites and a small particle size.

If powder metallurgy processes are used in accordance with the invention, then structures can be produced thereby in which more or less finely distributed wear-reducing structural constituents are embedded in a highly thermally conductive matrix.

However, the prerequisite for suitability as a contact matrix, namely the intimate and faultless bonding of the components copper and chromium, is not obtained through a melting operation, but rather by cold welding the structural constituents.

This process is preferred because the nature and proportion of the eutectic structural constituents can be varied, depending on whether the operation is in the hypoeutectic, hypereutectic or precise eutectic range.

For the purpose of simplification, the invention is described herein using zirconium oxide as an example of one of the eutectic microstructural constituents. However, it is understood that this description applies analogously to hafnium oxide. This is especially so since commercially available zirconium oxide materials frequently contain traces of hafnium oxide and hafnium oxide has essentially the same properties with respect to the conversion of the metastable tetragonal modification into the monoclinic modification.

By using eutectic micro-structural constituents, it is possible to adapt the ceramic shaped articles to the particular field of application to a much greater extent than possible by prior art methods.

Macroscopic segregations are understood to mean microstructural constituents which are present in the cast microstructure and form more than 10% by volume and, as individual phase fields, have a dimension of greater than 1 mm.

All powder-metallurgical processes used hitherto have resulted in the disadvantages typical of oxide-ceramic cermets, i.e. without subsequent hot compaction, the microstructure is porous, coarse (microstructural components usually being much larger than 10 ?m) and inhomogeneous, which results in inadequate strength as well as brittleness.

In spite of that basic relationship, the prior art attempts to achieve a resorption rate that is as high as possible by providing the internal surface of the material with particle-to-particle binding that is as weak as possible by using or “cultivating” constituents of the structure that are as finely particulate as possible.

If it were possible to join together the structural components, or grain segments, which have been separated by a crack and have an identical or virtually identical alignment, and to cure the areas, respectively neighboring subdomains could be coalesced to form a new domain.

Bonding of the copper and chromium components is achieved by cold-welding the structural components, wherein chromium powder with relatively narrow particle size distributions below 63 ?m is preferred.

While in this condition, the material of the container still possesses a homogenous, Austenite structure, the polishable surfaces of which have not been impaired by the coexistence of Austenite and martensite structural components.

In FIGS. 1 through 3 the structural constituents can be ascertained based on the brightness hue of the areas.