Alloys containing manganese

For prestressed concrete, either high-tensile steel wires or occasionally bars of steel alloy containing manganese and silicon, can be used. Galvanised wires may also be used for prestressed concrete, but it is recommended that they be chromated before use. 

The amount of iron and manganese in an alloy can be determined by precipitating the metals with 8-hydroxyquinoline, C9H7NO. After weighing the mixed precipitate, the precipitate is dissolved and the amount of 8-hydroxyquinoline determined by another method. In a typical analysis, a 127.3-mg sample of an alloy containing iron, manganese, and other metals was dissolved in acid and... 

Barium- and calcium-bearing manganese siUcon is used as an inoculant in gray and ductile iron. The alloy contains 60—65% Si, 9—11% Mn, 4—6% Ba, 1—3% Ca, and 1—1.5% Al. The combination of barium, calcium, and manganese provides excellent chill reduction, improves the graphite stmcture, and minimizes section sensitivity in castings having thin and thick sections. 

The physical and mechanical properties of steel depend on its microstmcture, that is, the nature, distribution, and amounts of its metaHographic constituents as distinct from its chemical composition. The amount and distribution of iron and iron carbide determine most of the properties, although most plain carbon steels also contain manganese, siUcon, phosphoms, sulfur, oxygen, and traces of nitrogen, hydrogen, and other chemical elements such as aluminum and copper. These elements may modify, to a certain extent, the main effects of iron and iron carbide, but the influence of iron carbide always predominates. This is tme even of medium alloy steels, which may contain considerable amounts of nickel, chromium, and molybdenum. 

Figure 10.7. Difi racUon paUern, prepared in an electron microscope, from a rapidly solidified foil of an A1 Mn alloy containing 14 at.% of manganese. Photograph made in 1984 (courtesy A.L. Greer...

Use Figure 17-11 to estimate the resistivities of two metal samples, one made of pure copper and the other of a copper-manganese alloy containing one atom of manganese for every one hundred copper atoms. Calculate the ratio of the cost due to power loss from wire of the impure material to the cost due to the power loss from wire of the pure material. 

Alloys are solid metallic mixtures designed to meet specific needs (see Section 5.15). For example, the frames of racing bicycles can be made of a steel that contains manganese, molybdenum, and carbon to give them the stiffness needed to resist mechanical shock. Titanium frames are used, but not the pure metal. Titanium metal stretches easily, so much so that it becomes deformed under stress. However, when alloyed with metals such as tin and aluminum, titanium maintains its flexibility but keeps its shape. 

Ferro-alloys Master alloys containing a significant amount of bon and a few elements more or less soluble in molten bon which improve properties of bon and steels. As additives they give bon and steel better characteristics (increased tensile sbength, wear resistance, corrosion resistance, etc.). For master alloy production carbothermic processes are used for large-scale ferro-sihcon, ferro-chromium, ferro-tungsten, ferro-manganese, ferro-nickel and metallothermic processes (mainly alumino and sihco-thermic) for ferro-titanium, ferro-vanadium, ferro-molybdenum, ferro-boron. 

Alloys. Tin is widely used as both a major and minor ingredient of alloy metals. These applications are summarized in Tables 1, 2, and 3. Phosphor bronzes (Table 3) actually contain very little phosphorus, ranging from 0.03 to 0.50%, and hence the alloys are poorly designated. Tin bronzes is the better term. High-silicon bronzes contain about 2.8% tin low-silicon bronzes about 2.0% tin. Gun metals are tin bronze casting alloys with a 5 10% zinc content. Some wrought copper-base alloys contain tin (1) Inhibited Admiralty metal, 1% fin (2) manganese bronze, 1% tin (3) naval brass, 0.75% tin, (4) leaded naval brass, 0.75% tin. See also Copper. 

Steel is an alloy containing chromium, manganese, molybdenum, nickel, vanadium and boron. Copper-nickel alloy, bronze and aluminium alloys are used in making coins. Fusible alloys having low melting points are used as solder and fuses in electrical circuits. 

Aluminum bronzes, copper-nickel alloy (69 Cu-30 Ni-1 Fe and copper-nickel alloys containing added manganese are resistant to impingement and cavitation-induced damage under flowing conditions. 

Bronzes are alloys of copper and tin and are generally more resistant to corrosion than brass, especially toward non-oxidising dilute acids. The bronzes which are used in pump heads and propellers for ships may contain manganese, nickel, and/or aluminium. 

---