Iron modulus

An LSF of 100 would indicate that the clinker can contain only C S and the ferrite soHd solution. Time saturation factors of 88—94 are frequentiy appropriate for reasonable bumabiUty low LSF indicates insufficient C S for acceptable early strengths, and higher values may render the mix very difficult to bum. Several other weight ratios such as the siUca modulus and the iron modulus are also important (21). 

Iron Modulus. The Al203 Fe203 ratio in a hydraulic cement. In portland cement this modulus usually lies between 2 and 3. Iron Notch. Alternative name for the TAPHOLE (q.v.) of a blast furnace. 

The iron modulus (IM), also known as the alumina ratio (AR), is the ratio of alumina to ferric oxide ... 

Since these two oxides both occur almost entirely in the liquid phase at clinkering temperature, this modulus characterizes the composition of that phase. If the ferric oxide content is higher, so that the iron modulus is lower, the viscosity of the melt decreases. For a value of IM < 0.638 the clinker phase called tricalciumaluminate (C3A) fails to form CjA-free cements are characterized by increased sulphate resistance. In industrial cements this modulus is generally between 1.3 and 4.0 and most often between 1.8 and 2.8. In special cements it may have much lower values (down to about 0.4). 

The viscosity of the liquid phase is lower with decreasing iron modulus (alumina ratio), i. e., with increasing Fe203 content. Subsidiary mix components also affect the viscosity, which is, for example, increased by alkalis, but decreased by SO3 and MgO. These reactions can be accelerated more particularly by increasing the proportion of liquid phase lowering the viscosity of the liquid phase ... 

For clinker with iron modulus 0.64 (rich in iron oxide, no C3A)... 

The relative compressive strengths (referred to the respective 2-day strengths = 100) show the different amounts of hardening. With iow siiica moduius and iron modulus, as also with low lime standard, the subsequent hydration reactions still contribute a great deai to the strength attained. These diagrams, too, are merely approximate indications of trends. 

Fig. 21 Relative compressive strengths as a function of lime standard, silica modulus and iron modulus, referred to the respective 2-day strengths (laboratory cements)...

It is further necessary to check that the composition of the raw mix calculated in this way is within the permissible limits (Table 1) and to ascertain its lime standard (more particularly LStlll, which in this case is 95.7) and moduli (in this case silica modulus = 2.0, iron modulus = 2.4). If necessary, a different lime content will have to be chosen or corrective materials added. 

Fig. 19 Relative compressive strengths associated with variation of the iron modulus (laboratory cements referred to cement with lime standard KStI = 95 silica modulus 2.0 alumina modulus 2.0 2.8% SO3 fineness 3200cm /g Blaine)...

Another anomalous property of some nickel—iron aHoys, which are caHed constant-modulus aHoys, is a positive thermoelastic coefficient which occurs in aHoys having 27—43 wt % nickel. The elastic moduH in these aHoys increase with temperature. UsuaHy, and with additions of chromium, molybdenum, titanium, or aluminum, the constant-modulus aHoys are used in precision weighing machines, measuring devices, and osciHating mechanisms (see Weighing AND proportioning). 

Gray cast iron is the most commonly used cast iron and is the least expensive. It is the easiest to cast and machine. The tensile strength of gray cast iron ranges from 155 to 400 N/mm (10 to 26 ton/in. ). The tensile modulus ranges from 70 to 140 kN/mm and the hardness from 130 to 300 DPN. 

This very approximate model gives reasonable agreement with such disparate materials as iron, quartz and sodium chloride with a 0.14. Alternatively, of course, if we know the melting point, we can obtain an estimate of the elastic modulus. 

U.S. market is about 20 million pounds per year. The applications are those where one needs very high flame resistance (clothing for firefighters and welders, welder s protective shield, upholstery and drapes), heat resistance (ironing board covers, insulation film for electrical motors and transformers, aerospace and military), dimensional stability (fire hose, V- and conveyor belts), or strength and modulus (circuit boards, bulletproof vests, fiber optic and power lines, ship mooring ropes, automobile tire cord, puncture-resistant bicycle tires). 

Soft white, ductile metal high-purity metal is very ductile at ordinary temperatures occurs in three allotropic forms (i) body-centered cubic form, alpha iron stable up to 910°C, (ii) face-centered cubic form, gamma iron occurring between 910 to 1,390°C, and (iii) body-centered delta iron allotrope forming above 1,390°C. Density 7.873 g/cm at 20°C melting point 1,538°C vaporizes at 2,861°C hardness (Brinell) 60 electrical resistivity 4.71 microhm-cm at 0°C tensile strength 30,000 psi Poisson s ratio 0.29 modulus of elasticity 28.5 X 10 psi thermal neutron absorption cross-section 2.62 bams velocity of sound 5,130 m/s at 20°C. 

A second mechanism in the. aging of CTPB propellants also exists and proceeds concurrently with the reactions proposed above. It consists of an attack at the reactive points of unsaturation in the backbone polymer, which causes additional crosslinking and hence an increase in propellant modulus, particularly at the surface. The exposed surface of CTPB propellants changes, as indicated by an increase in hardness. Heavy metal ions are particularly harmful, and it was found that an increase from 10 to 80 p.p.m. of iron caused a significant increase in surface hardening by catalytic attack on the double bonds. Antioxidants in general provide sufficient protection for polymer storage. In CTPB propellants the antioxidant selected to protect the double bond is very important. Amine-type antioxidants have provided better surface stability than phenolic compounds. 

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