aqueous polymer quenchants are being used increasingly in steel heat treatment industries as a substitution for conventional quenchants. by adjusting the quench parameters of the polymeric media, it is possible to achieve desirable microstructure and mechanical properties in addition to reduction in distortion and cracking. in this work, polyalkylene glycol (pag) aqueous solution was used as th...

The problems of thermodynamic analysis associated with the heat exchangers that used in cryogenic technology are discussed. Heat high and medium pressure air separation fluidizing plants operating at different temperature levels were selected for modelling. There many features according to which classification is made. These include such facts as number flows working fluid, relative direction s...

Nonsorted circles are relatively barren patterned-ground features common in most arctic tundra regions. We studied how vegetation changes on nonsorted circles might affect cryogenic processes, which is of relevance as arctic vegetation responds to climate change. Twenty-eight circles at a moist nonacidic tundra site in northern Alaska received one of four treatments: (a) vegetation removal; (b)...

the effect of ferrite grain size on the fatigue and tensile properties of dual phase steels with a 0.25 volumefraction of martensite (vm) under different heat treatments was investigated. the heat treatments werehomogenized at 1200 oc along with several subsequent normalizations at 910 oc, resulting in differentmicrostructures and mechanical properties. after heat treatment, the obtained steels...

despite having some useful properties, stainless steels suffer from lack of suitable surface hardness. in this research electroless ni-b-tl coating was used with the aim to increase their surface hardness. the effects of nickel chloride, sodium borohydride, thallium nitrate and ethylendiamin on the chemical composition of coating were studied. to achieve an increase in hardness, the effects of ...