Chromium stainless

Carbon disulfide is normally stored and handled in mild steel equipment. Tanks and pipes are usually made from steel. Valves are typically cast-steel bodies with chrome steel trim. Lead is sometimes used, particularly for pressure reUef disks. Copper and copper alloys are attacked by carbon disulfide and must be avoided. Carbon disulfide Hquid and vapor become very corrosive to iron and steel at temperatures above about 250°C. High chromium stainless steels, glass, and ceramics maybe suitable at elevated temperatures. 

In the stainless group, nickel greatly improves corrosion resistance over straight chromium stainless. Even so, the chromium-nickel steels, particularly the 18-8 alloys, perform best under oxidizing conditions, since resistance depends on an oxide film on the surface of the alloy. Reducing conditions and chloride ions destroy this film and bring on rapid attack. Chloride ions tend to cause pitting and crevice... 

C) 370/656X brittleness after exposure to temperatures between about 700 to 1. OSO-F. stainless steels. chromium stainless steels, over 13% Cr and any 400 Series martensitic chromium stainless steels low in carbon content (high Cr/C ratio). complex chromium compound, possibly a chromium-phosphorus compound. chromium steels at temperatures above about 700 F (370 C) keep carbon up in martensitic chromium steels and limit Cr to 13% max. 

Copper additions seem to be helpful to avoid pitting. Submerged specimens in New York Harbor produced excessive pitting on a 28 percent Chromium stainless but no pitting on a 20 Cr-1 Cu alloy for the period of time tested. 

Lizlovs, E. A. and Bond, A. P., Polarisation Behaviour of High-purity 13 and 18% Chromium Stainless Steels , J. Electrochem. Soc., 119, 219c (1972)... 

Imoi, H., Saito, Y., Kobayashi, M. and Fujiyama, S., Pitting-corrosion-resistant Chromium Stainless Steel , Japan Kokai 7300, 221 (1973) C.A., 79, 22569a Sato, E., Tamura, T. and Okabe, T., Aluminium Anode for Cathodic Protection. 7 Pitting and Corrosion Potentials for Gallium in Sodium Chloride Solutions , Kinzoku Hyomen Gijutsu, 24, 82 (1973) C.A., T9, 12792d... 

Acid etching can be used to treat types 301 and 302 of stainless. These processes result in a heavy black smut formation on the surface. This material must be removed if maximum adhesion is to be obtained. The acid etch process produces bonds with high peel and shear strengths. The 400 series of straight chromium stainless steels should be handled in the same manner as the plain carbon steels. The various types of precipitation hardening (PH) stainless steels each present an individual problem. Processes must be adopted or developed for each type. 

Chromium Stainless steel, leather tanning, plating, alloys South Africa, Turkey, Zimbabwe 82... 

Chromium Stainless steel (especially for parts exposed to corrosive gases and high temperatures) -91%... 

Series ferritic chromium stainless steels, over 13% Cr and any 400 Series martensitic chromium stainless steels low in carbon content (high Cr/C ratio). 

Ferritic stainless steels, such as straight chromium stainless steels containing 12% chromium, may be embrittled at 750°F to 975°F (425°C to 525°C). Embrittlement is not evident at high temperatures, but lack of ductility can occur at ambient temperatures it is called 885°F (475°C) embrittlement (or blue embrittlement ). This embrittlement is reversible at higher temperatures. Alloys that embrittle, if used in pressure-containing services, should not be exposed to temperatures >650°F (345°C). However, some common domestic codes allow design stresses up to 1200°F (650°C). In most cases, these codes caution that these materials may embrittle. 

Pure nickel was first isolated in 1751. Like cobalt, nickel was used to color glass, though nickel compounds turn glass and other substances green rather than blue. Because nickel is resistant to corrosion, it is often combined with other metals to form alloys that resist oxidation. A process known as electroplating uses nickel to coat the surface of metals that are vulnerable to corrosion, like iron or steel. Stainless steel is an example of a product made from nickel almost half the nickel that is mined each year is used to manufacture it. Also composed of chromium, stainless steel is extremely resistant to corrosion. Another nickel alloy is monel, which is made with copper. Monel is hard and resistant to corrosion, making it ideal for commercial marine applications such as the manufacture of boat propellers. The heating parts in toasters and electric ovens are made from an alloy called nichrome, which is another metal, made from chromium and nickel. 

Castle and Durbin (5) used x-ray photoelectron spectroscopy (XPS) to investigate the surface composition of 9% nickel and 12% chromium stainless steels that were subjected to oxidizing atmospheres at 500°C. Fe O was predominant in the surface lager and a Cr O ... 

The greatest problems with austenitic stainless steel piping usually arise when the unit is off stream rather than when it is operating. Such problems must be anticipated. The use of stainless steels requires that the necessary steps be taken to avoid them. Chlorides and caustics can cause any austenitic stainless steel pipe to crack trans-granularly under some conditions. Plain chromium stainless steels do not crack in chloride solutions, but they usually pit badly enough to be only moderately satisfactory. 

Work is in progress on single-crystal sapphire and a high-chromium stainless steel. Work is planned on aluminum and graphite. 

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