Chromium-containing alloys

Steel is an alloy containing chromium, manganese, molybdenum, nickel, vanadium and boron. Copper-nickel alloy, bronze and aluminium alloys are used in making coins. Fusible alloys having low melting points are used as solder and fuses in electrical circuits. 

Nickel alloys containing chromium and iron of the composition given in Table 4.38 are used widely in chemical, petrochemical and other high-temperature processes. 

Thermodynamic predictions were consistent with experimentally measured corrosion rates and open circuit potentials. The results indicate enhanced corrosion of stainless alloys containing chromium may be expected in supercritical water. These corrosion rates appear comparable to those for mild steel or iron. 

When iron-, nickel-, and cobalt-base alloys containing chromium were oxidized in air at 900 °C for 25 h ° only oxide scales were formed and nitride formation was observed only on a Co-35 wt% Cr alloy. Presumably the inward diffusion of... 

It is clear that, in order to protect alloys containing chromium from oxidation, atmospheres based on the CO2-CO system cannot be used if carburization is to be avoided. Here, and in other cases where strong carbide formers are involved, protection may be achieved by using the H2—H2O system for which the relevant... 

Min] Miner, R.G., Nagarajan, V., The Morphology of Scale Growth on Iron-base Alloys Containing Chromium and Silicon , Oxid. Met., 16(3-4), 295-311 (1981) (Experimental, Morphology, 6)... 

Mortimer DA, Nicholas M, Crispin RM, The comparability of carbon with copper alloys containing chromium, titanium or vanadium, International Conf on Carbon Fibers, their place in Modern Technology, The Plastics Institute, London, Paper 15, Feb 1974. 

Induction could be used with conventional tools built by any tool maker. Induction coils can be mounted with quick disconnects, so that they can be reconfigured for a tool change, which can be done by two people in half a day. Nevertheless, the mold block must be made of a magnetic steel alloy containing chromium or nickel for efficient electromagnetic conduction. Aluminum and P20 tool steel are not conductive enough. Some alloys heat fast by induction and reach temperatures up to 400°C (750°F). Others heat more slowly and peak at temperatures as low as 250°C (480°F). 

Constantan is an alloy of 60% copper and 40% nickel. Chromel is a trademark fur a scries of alloys containing chromium, nickel, and at limes, iron. Alumel is an alloy of nickel with 2% aluminum, 2% manganese, and... 

This result is partly explained by the fact that the corrosion resistance in the case of a metal depends on the presence at its surface of reaction layers, sometimes only a few atom layers thick, resulting from an interaction between the material and the surrounding environment. Such layers can be classified as oxides, solid precipitates, adsorbed layers, or passive surface films. Some of them like dense oxide layers, precipitates, or passive films play a protective role by isolating the underlying metal from a direct contact with a surrounding corrosive environment. This is particularly true in the case of stainless steels and other alloys containing chromium. Their passive surface film formed in ambient air or in contact with an... 

Stainless steels are not resistant to molten hydroxides, particularly sodium and potassium hydroxides, because of chromium dissolution related to peroxide formation. However, they do perform well in molten carbonates up to 930°F (500°C). Above 1290°F (700°C), nickel-based alloys containing chromium are required. 

This technique has been especially useful to assess localized corrosion for passivating alloys such as S31600 stainless steel, nickel-based alloys containing chromium, and other alloys such as titanium and zirconium. Though the generation of the polarization scan is simple, its interpretation can be difficult [7]. 

Experimental work related to chromium-carbide-carbon equilibrium on a nickel base alloy (15% chromium, 10% iron, balance Ni), showed that the carbon solubility in nickel base alloys is lesser than in austenitic steels. Nickel-based alloys containing chromium can be sensitized in the temperature range 500-700°C. 

The susceptibihty to grain boundary attack of nickel-based alloys containing chromium at temperatures above 593 °C (1100 °F) under reducing conditions and above 760 °C (1400 °F) under oxidizing conditions. 

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