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Microcap & Penny Stocks : DCH Technologies (DCH) -- Ignore unavailable to you. Want to Upgrade?

To: c.horn who wrote (1482)	5/15/1999 6:28:00 PM
From: Scoobah	Respond to of 2513

Great find. Their only hope is preventative corrosion monitoring; As metals corrode, atomic hydrogen migrates through the metal and combines in the air surrounding the metal to make molecular hydrogen. The amount of hydrogen emanating form the metal can be indicative of corrosion occurring inside the metal. As bridges age, internal corrosion becomes a concern. dch-technology.com

To: c.horn who wrote (1482)	5/15/1999 7:05:00 PM
From: Dan B.	Read Replies (1) \| Respond to of 2513

Thanks c.horn, geez, education can be a bitch. That was rather dry, was there anything in there that particularly stood out in your mind? Just that this is a pretty big business I suppose?

To: c.horn who wrote (1482)	5/16/1999 1:58:00 AM
From: Rickmas	Read Replies (6) \| Respond to of 2513

Guarding Against Hydrogen Embrittlement Treseder, R.S. - Chemical Engineering, 88(13):105-108 1981 Four forms of metals which have loss of ductility resulting from absorption of hydrogen are discussed in this paper. Known as hydrogen embrittlement this loss of ductility is potentially catastrophic as it can result in cracking or fissuring of metal. "High-temperature attack" is when at above 430 degrees F (220 C) hydrogen atoms permeating carbon steel can gradually react with iron carbide in the steel to form methane. The effect is two-fold, l) decarburization of steel with resultant loss of strength, and 2) fissuring of steel by the pressure of methane formed at the grain boundries. "Hydrogen stress cracking" generally occurs at temperatures below 250 degrees F (160 C), the effects can be most severe at room temperature. It results from the initial presence or absorption of hydrogen in metals, in combination with residual or applied stress, and also causes cracking in metals, i.e. steel. "Sulphide stress cracking" is defined as brittle failure by cracking under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulphide. It has been a problem in the petroleum industry, encountered in the production and transportation of sour natural gas and sour crude oil and oil refining. Subsurface voids produced by hydrogen absorption in (usually) low strength alloys with resultant surface bulges is known as "Hydrogen blistering". Experienced first in storage vessels handling sour gas or sour oil, corrosion in the tanks was caused by a combination of moisture and hydrogen sulphide. The author discusses these four forms of hydrogen embrittlement and suggests ways in which they can be monitored and in some cases solved.