Quenchants

When a component at an austenitizing temperature is placed in a quenchant, eg, water or oil, the surface cools faster than the center. The formation of martensite is more favored for the surface. A main function of alloying elements, eg, Ni, Cr, and Mo, in steels is to retard the rate of decomposition of austenite to the relatively soft products. Whereas use of less expensive plain carbon steels is preferred, alloy steels may be requited for deep hardening. 

Thermal shock failures using water result from the water vapor entering the enamel layer through small, submicroscopic cracks formed at the instant of shock. The water condenses in the cracks and in the bubbles of the enamel traversed by the cracks. On subsequent heating, the vapor from the entrapped water expands to cause spalling of the enamel layer. Other quenchant Hquids, such as toluene, oils, and other organic Hquids, also cause fine, almost invisible cracks, but thermal shock failures do not result with these quenchants on subsequent heating (39). 

Poly(vinyl alcohol) will function as a non-ionic surface active agent and is used in suspension polymerisation as a protective colloid. In many applications it serves as a binder and thickener is addition to an emulsifying agent. The polymer is also employed in adhesives, binders, paper sizing, paper coatings, textile sizing, ceramics, cosmetics and as a steel quenchant. 

This process, also termed rapid spinning cup (RSC) process, was invented in the early 1980 s contemporarily by Osaka University in Japan[191] and Battelle s Columbus Division in the US)192 Unlike water atomization where water streams or droplets are used to disintegrate a molten metal, a coherent fast-moving liquid layer is used in the RSC process. Liquid quenchants include water, oil, glycerine, and other commercial quenching liquids. The materials atomized with the spinning cup method include a wide variety of metals and alloys such as tin, lead, aluminum alloys, copper alloys, iron alloys (stainless steels and high speed tool steels), zinc alloys and superalloys.[192]... 

Propylene Oxide. Propylene oxide is another basic chemical used in manufacturing intermediates for urethane foams (cushioning and insulation), coatings, brake fluids, hydraulic fluids, quenchants, and many other end uses.23 The classic industrial synthesis of this chemical has been the reaction of chlorine with propylene to produce the chloro-hydrin followed by dehydrochlorination with caustic to produce the alkylene oxide, propylene oxide, plus salt. 

Use High-temperature lubricants, low-temperature fluids, compressor lubricants, hydraulic brake fluids, quenchant fluid, heat-transfer fluids, textile lubricants, rock drill lubricants, leather and papertreating compounds, rubber lubricants, plasticizers and solvents, chemical intermediate, stationary phase in gas chromatography. 

G. E. Totten, C. E. Bates, and N. A. Clinton, Handbook of Quenchants and Quenching Technology, American Society of Metals, Materials Park, Ohio, 1993. 

After the body temperature is lowered sufficiently, the film boiling gave way to the nucleate one. According to data, presented in the previous section, over the polymer concentration ranges, typical for high-molecular quenchants, the a value must decrease in comparison with water. In fact, this is normally observed in experiments. Rise of the temperature, characterizing transition from nucleate boiling to convective heat transfer, is associated with the increase in liquid viscosity. 

CA Index Name Phenol, 4- [5-(4-methyl- 1-piperazinyl) [2,5 -bi-l//-benzimidazol]-2 -yl]-, hydrochloride (1 3) Other Names Phenol, 4-[5-(4-methyl-l-piperazinyl) [2,5 -bi-l//-benzimidazol]-2 -yl]-, trihydrochloride Phenol,/)-[5-[5-(4-methyl-l-piperazinyl)-2-benzimidazolyl]-2-benzimidazolyl]-, trihydrochloride 2 -(4-Hydroxyphe-nyl)-5-(4-methyl-l-piperazinyl)-2,5 -bi-l//-benzimid-azole 2- [2- (4-Hydroxyphenyl) -6-benzimidazolyl] -6- (1 -methyl-4-piperazinyl)benzimidazole trihydrochloride 2-[2-(4-Hydroxyphenyl)-6-benzimidazolyl]-6-(l-methyl-4-piperazyl)-benzimidazole trihydrochloride 2-[2-(4-Hydroxyphenyl)-6-benzimidazolyl]-6-(l-methyl-4-pi-perazyl)benzimidazole trichloride 2-[2-(4-Hydroxyphe-nyl)-6-benzimidazolyl]-6-(l-methyl-4-piperazyl)benzi-niidazole-3HCl 4-[5-[5-(4-Methyl- l-piperazinyl)-2-ben-zimidazolyl]-2-benzimidazolyl]phenol trihydrochloride Bisbenzimide Bisbenzimide (quenchant) Bisbenzimide trihydrochloride H 33258 HOE 33258 Ho 33258 Hoechst 33258... 

Metal-working lubricants, hydraulic fluids, drilling lubricants, metal-cleaning formulations, flocculants, quenchants... 

The same features, however, proved successful in the commercial use of the poly(alkylene oxide)s as machine lubricants, metal-working lubricants, quenchants, and hydraulic fluids. The solubility of ethylene oxide/ propylene oxide copolymer glycols in water has led these formulations to be universally accepted as "hydrolubes" and brake fluids where the nonflammability and wide temperature service range of a blend of polyol and water are key features. 

Aqueous polymer quenchants [solutions composed of water and a polymer—normally poly(alkylene glycol) or PAG] have recently been developed that provide quenching rates between those of water and oil. The quenching rate can be tailored to specific requirements by changing polymer concentration and qnench bath temperature. 

Uses Lubricant for textiie fibers, machines, gearoiis, mbber, mandrei and moid reiease, compressors, cosmetics/personai care, heat transfer fluids, elec, chems., quenchants, foam control, solder assist chem. intermediate Properties Liq. sol. in water sp.gr. 1.03M vise. 51.9 cSt (40 C), 11.0 cSt (100 C) ... 

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