Types of steels

Technical molybdic oxide can be reduced by reaction of ferrosiUcon in a thermite-type reaction. The resulting product contains about 60% molybdenum and 40% iron. Foundries generally use ferromolybdenum for adding molybdenum to cast iron and steel, and steel mills may prefer ferromolybdenum to technical molybdic oxide for some types of steels. 

Ferrophosphoms is produced as a by-product in the electrothermal manufacture of elemental phosphoms, in which iron is present as an impurity in the phosphate rock raw material. The commercial product contains ca 23—29% P and is composed primarily of Fe2P [1310-43-6] and Fe P [12023-53-9] along with impurities such as Cr and V. Ferrophosphoms is used in metallurgical processes for the addition of phosphoms content. Low concentrations (up to - 0.1%) of phosphoms in wrought and cast iron and steel not only increases the strength, hardness, and wear resistance but also improves the flow properties. In large stmctural members and plates, it is desirable to use a type of steel that does not need to be quenched or tempered, and thus does not exhibit weld-hardening. This property is afforded by the incorporation of a small quantity of phosphoms in steel. Ferrophosphoms from western U.S. phosphoms production is used as a raw material for the recovery of vanadium (see Vanadiumand vanadiumalloys). 

There are several hundred types of steels that use these principles separately or in combination. Some of these are generic, many are proprietary. Among them are various microaUoyed ferrite—peadite steels having limited peadite amounts and the low carbon bainites, as weU as the dual-phase steels. 

The principal effects of air pollutants on metals are corrosion of the surface, with eventual loss of material from the surface, and alteration in the electrical properties of the metals. Metals are divided into two categories—ferrous and nonferrous. Ferrous metals contain iron and include various types of steel. Nonferrous metals, such as zinc, aluminum, copper, and silver, do not contain iron. 

Stress-corrosion cracking of all types of steels formed the topic of a recent conference , the proceedings of which deal in some detail with the effect of structure on the stress-corrosion susceptibility of these alloys. 

The behaviour of steel depends very much on the alloying elements present for any given environment. Thus the decrease in corrosion rate with time for mild steel is very much slower than for a low-alloy steel. This can be attributed to the much more compact nature of the rust formed on the latter type of steel and this is clearly illustrated in Figs. 2.14(o) and (ft). 

Soups and sauces These products may involve highly corrosive mixtures, in this case from combined chlorides and acidity. For this reason it is often necessary to use the molybdenum-bearing type of steel. 

In general the efficiency increases with an increase in inhibitor concentration—a typical good inhibitor gives 95% inhibition at a concentration of 0-008% and 90% at 0-004%. Provided the inhibitor is stable, increase in temperature usually increases the efficiency although the actual acid attack may be greater. A change in acid concentration, or in type of steel, may also alter the efficiency. Thus, the conditions of a laboratory determination of efficiency should closely simulate the conditions expected in commercial practice. 

Two general types of sheet steel are in current use, viz. cold-rolled mild steel and decarburised steel. A typical analysis for cold-rolled steel is 0-1% C, 0-5% Mn and 0-04% S. It can be obtained in regular, deep drawing or extra-deep drawing grades. This type of steel is normally used with a ground-coat including cobalt and nickel, as shown in Table 16.1. 

Decarburised steel is a mild steel that has undergone a heat treatment in a controlled atmosphere to reduce the carbon content to about 0-005 This type of steel can be used for white or coloured enamel direct to steel. 

The most common types of steels used in castings are carbon steels, which contain only carbon as the major alloying element. Carbon steels are classified by their carbon content into three groups low-carbon steel (C < 0.20%), medium-carbon steel (C = 0.20 to 0.50%), and high-carbon steel (C > 0.50%). Steel s hardness also depends upon the carbon content. 

Damascus steel, also known in the Western world as Damascene steel, is a special type of steel that was and is still used to make sward and knifeblades. Apparently, Damascus steel was first made in India, where it was known as wootz or kuft, and later (during the second century b.c.e.) it was developed in Persia. The name "Damascus steel" was used by the Crusaders to describe the steel used by sword smiths of Damascus, Syria, famous for their ability to hammer and temper the steel into fine blades. The sword blades made from the steel had a reputation for their exceptional properties, especially their toughness, the retention of their cutting edge, as well as for a particular and characteristic decorative pattern on their surface (Figiel 1991). 

In general, detonation test apparatus consists of a steel tube that is filled with the substance under investigation. One end of the tube is provided with a booster charge consisting of an electric detonator covered by detonative material. The other end is either closed or provided with a witness plate. One type of steel tube apparatus is provided with a velocity probe to record the shock wave velocity as shown in Figure 2.28. 

The covers are constructed from aluminum or some type of steel. This should provide adequate protection from being pierced or cut through. The metals are corrosion resistant so that they will not corrode or become fragile from extreme weather conditions in outdoor applications. The bolts used to install each of these systems are galvanized steel. In addition, the bolts for each cover are installed on the inside of the unit so they cannot be removed from the outside. 

Which two types of steel appear to have their properties combined in tempered steel ... 

Neodymium is magnetic and is used in many of the most powerful magnets in the world. Some types of steel contain up to 18% neodymium as an alloy. It is also used as a color for TV tubes and as a tint for eyeglasses. 

With aflame length of 13.9 m, the jet flame will impinge on the steel structure overhead. Consequently, the steel will see high convective and radiative heat fluxes on the order of 200 kW/m. Since the structure will be exposed to direct flame impingement, the expected failure time would be 3-4 minutes (Table 5-7) or less due to the high heat flux from the jet fire, depending on the type of steel structure and design factor of safety. 

A four- or five-digit numbering system has been established to classify and identify different types of steel. Originally developed by the Society of Automotive Engineers (SAE) this system is now used by the American Iron and Steel Institute (AISI) to classify steel. 

It should be noted that equation (13) is for a specific stainless steel and a particular type of tube. Before employing the equation to fabricate a column the original reference should be reviewed to ascertain the correct constants or function to employ for the type of steel and tube that is intended for use. 

The entectoid transformation is an important one not only for this specific carbon composition, bnt for classifying all types of steels. Carbon steels have carbon contents between 0.1 and 1.5 wt%. Those with carbon contents less than 0.8% are termed hypoeutectoid steels, and those with greater than 0.8% C are called hypereutectoid steels. Further classifications of steels are given in Table 2.4. 

Many other atom-probe analyses of different phases in different types of steels exist as steels are one of the most important materials. It is possible to investigate how the magnetic properties of alloys are correlated to the microstructures of different phases in the alloys.57,58,59 The chemical contents, growth process and structures of metallic carbides in different alloy steels have been studied with the field ion microscope and the atom-probe field ion microscope.60 61 62 63 We refer the reader to some of the original papers published on these subjects. 

---