Steel twinning

When mechanical vibration of dipyridinium dications (see Scheme 7-7) was conducted with a stainless steel ball in a stainless steel twin-shell blender at room temperature under... 

Outlet Superheater (SH) header of Unit 3 (600 MW. supercritical multi-fuel l of an ENEL power station it consists of 2 twin and independent bodies (22 m length, 488.5 mjn internal diameter, 76.2 mm thickness material SA 430 TP 321H stairdess steel). This header has suffered from relevant cracking problems in assembly welds after 108.000 hours of service and... 

Examination of the microstructure of the cavitated surface will commonly disclose evidence of deformation such as twins (Neumann hands) in carbon steel and general cold working in other metals (Case History 12.6). Damage from cavitation can be differentiated from attack by a strong mineral acid, which can produce a similar surface appearance, by observing the highly specific areas of attack characteristic of cavitation. Acid attack is typically general in its extent (Case History 12.6). 

Figure 6.5. Dislocation networks and deformation twins in 4340 steel shock loaded to 15 GPa.

On cooling to room temperature after annealing, maraging steels transform completely to martensite. The as-annealed structure consists of packets of parallel lath-like martensite platelets arranged within a network of prior-austenite grain boundaries. The platelets have a high dislocation density but are not twinned. 

The actual cylinders and pistons of a two-headed pump are constructed in a very similar manner to the single piston pump with a sapphire piston and a stainless steel cylinder. Each cylinder is fitted with nonreturn valves both at the inlet and outlet. The cams that drive the two pistons are carefully cut to provide an increase in flow from one pump while the other pump is being filled to compensate for the loss of delivery during the refill process and thus, a fall in pressure. A diagram of a twin-headed pump is shown in figure 10. 

World Trade Center twin towers, 3000 died, 10 billion loss, insufficient fire protection to steel structure ... 

For the more vigorous reactions, a twin-cell calorimeter was devised (188). It consisted of two nickel cylinders connected by a stainless steel needle valve and tubing and held rigidly to a metal top-plate. The cylinders and connections were immersed in a wide-necked Dewar vessel containing carbon tetrachloride which would react mildly with any BrF3 that escaped. Bromine trifluoride contained in one cylinder was transferred to the solid contained in the other cylinder by opening the valve and applying controlled suction. All measurements were made externally on probes in the carbon tetrachloride. 

The radiation source for the twin calorimeter of figure 10.2 is a 100 W tungsten lamp. The wavelength is selected by a monochromator, and the light is split in two parts and led into the radiation-absorbing cells of each unit by three light cables. With a 2 mm slit, the band pass is about 13 nm, and for radiation with A = 436 nm the power delivered to each cell is about 60 p,W. The reference cells are simply steel rods and receive no light. 

About 90% of all the zirconium produced in the United States is used in the nuclear electrical power industry. Since it does not readily absorb neutrons, it is a desired metal in the manufacture of nuclear reactors and their fuel tubes, but it must be free of its twin hafnium for these purposes. Zirconium is also used as an alloy with steel to make surgical instruments. 

The burner is shown in Fig. 1 b. Its screw (A) and cone (B) fit into the cell opening [5] (see Fig. 1 a). The injector nozzle (C) has two concentric tubes to inject two gases simultaneously, if desired. The outer tube is of stainless steel with 3 mm o.d. and 1.5 mm i.d. The inner capillary of the same material, which protrudes slightly, has 0.8 mm o.d. and 0.5 mm i.d. Both concentric tubes can receive gas separately from the twin valve (D) below, which can be heated to 50°C to prevent formation of solid gas hydrates. 

Other common continuous mixers involve substantial modification of single and twin screw extruders, aimed at improving distributive mixing capability in particular, and leading to the development of continuous mixers such as the Transfermix (50) and the Buss Ko-Kneader (51). Another approach in continuous mixer development is to transform batch mixers into continuous ones. Thus, the roll-mill can be converted into a continuous mixer by feeding raw material on one side and continuously stripping product on the other side. In addition, the Banbury mixer was imaginatively transformed into the Farrel Continuous Mixer (FCM) by Ahlefeld et al. (52), and, later, two similar continuous mixers were developed by Okada et al. (53) at Japan Steel Works and by Inoue et al. (54) at Kobe Steel. 

Although screw elements with nitride layers are standard for twin screw extruders, they are only used for products that present neither abrasive nor corrosion risks. Al-alloyed nitrided steels are generally used because the nitriding achieves a high surface hardness. 

Figure 5 BASF belt process for high molar mass polyisobutene, (a) moving steel belt (b) twin-screw extruder (c) finishing unit (d) purification of flash-off ethylene. (From Ref. 18, courtesy of VCH Publishers, Weinheim.)...

Figure 3.27. Deformation pathways for (a) shape-memory alloys, showing the reversible movement of twin boundaries. Shown in (b) is the irreversible slip deformation of other alloys, such as carbon steels.

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