Tool steels tungsten

Microtomy refers to sectioning materials with a knife. It is a common technique in biological specimen preparation. It is also used to prepare soft materials such as polymers and soft metals. Tool steel, tungsten carbide, glass and diamond are used as knife materials. A similar technique, ultramicrotomy, is widely used for the preparation of biological and polymer specimens in transmission electron microscopy. This topic is discussed in Chapter 3. 

Aluminum chlorohydrate Sodium hypochlorite elasticity improver, high-speed tool steel Tungsten... 

Ammonium alum Diacetyl Glutaral Glyoxal hardener, gelatin contraceptive creams Paraformaldehyde hardener, gelatin/protein glues Potassium alum anhydrous hardener, high-speed tool steel Tungsten... 

High-speed-tool steels (tungsten alloys)... 

Niobium in Tool Steels. In the matrix method of tool-steel development, the composition of the heat-treated matrix determines the steel s initial composition. Carbide volume-fraction requirements then are calculated, based upon historical data, and the carbon content is adjusted accordingly. This approach has been used to design new steels in which niobium is substituted for all or part of the vanadium present as carbides in the heat-treated material. Niobium provides dispersion hardening and grain refinement, and forms carbides that are as hard as vanadium, tungsten, and molybdenum carbides. 

Tungsten Is used in tool steels to maintain hardness at elevated temperatures. 

Alloys.1—The most important alloy of molybdenum is ferro-molybdenum, which is used as an addition to steel. The effect of molybdenum on steel is similar to that of tungsten, but is more marked the tensile strength is increased and the elastic limit raised. For highspeed tool-steels molybdenum is often used in conjunction with tungsten. It has been found that the addition of molybdenum in small quantities (up to 15 per cent.) to steel increases the liability to corrosion, especially in acid and salt solutions. An important use of steels containing 3 to 4 per cent, of molybdenum and 1-0 to 1-5 per cent, of carbon is for the manufacture of permanent magnets. ... 

High speed steels are highly alloyed tool steels which exhibit enhanced hardness and wear resistance at high temperatures. These steels have a high carbon content and varying amounts of chromium, molybdenum, tungsten and vanadium. 

Loss by recycling dilution includes residues containing low tungsten concentrations as a result of recycling, and are not uneconomical to recover. For example, tungsten as trace constituent in recycling of tool steel, carbides, etc. is lost into the steel melt. 

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