Structural-quality steels

Low-carbon plate and sheet are made in three qualities fully killed with silicon and aluminum, semikiUed (or balanced), and rimmed steel. Fully killed steels are used for pressure vessels. Most general-purpose structural mild steels are semikiUed steels. Rimming steels have minimum amounts of deoxidation and are used mainly as thin sheet for consumer applications. 

The vast majority of metallic shells for Corrosion Resistant Masonry (CRM) lined vessels have been made of ASME, (American Society of Mechanical Engineers) SA-36 or SA-283 Grade C structural quality carbon steel, sometimes... 

Steel tire cord is manufactured from high-quality steel, which is necessary because of the performance demands to which tires are subjected. The composition of a typical steel cord is illustrated in Table 14.5. The key mechanical properties governing a steel cord or wire are its tensile strength, elongation, and bending stiffness. A tire cord construction is normally defined by the structure, the length of lay, and the direction of lay. The hill description of a steel cord is given by... 

Rolling temperatures of high quality steel bars have fallen from about 2200 F (1200 C) to about 1850 F (1283 C) in the process of improving fine-grain structure. The limiting of decarburization by rolling as cold as possible also has reduced rolling temperatures. 

Phosphorus tends to segregate in poor-quality steels. In rolled steel with too much P, polished and etched sections show distinct bands of metal phosphide ( phosphorus banding ). Very fine grain structure and superplasticity at high temperatures is shown by ferrous alloys with compositions, for example, Fe = 98.6%, Mn = 1.16%, P = 0.5%, V = 0.1%, C = 0.14%. The composition of some typical steels are listed in Table 12.56. 

A 572 High-strength low-alloy niobium-vanadium steels of structural quality Nb, V, N Plate, bar, and sheet piling < 150 mm in thickness Yield strength of 290 to 450 MPa in six grades Welded, bolted, or riveted structures, but many bolted or riveted bridges and buildings... 

A 690 High-strength low-alloy steel H-piles and sheet piling Ni, Cu, Si Structural-quality H-pills and sheet piling Corrosion resistance two to three times greater than that of carbon steel in the splash zone of marine marine structures Dock walls, sea walls Bulkheads, excavations and similar structures exposed to seawater... 

Class I carrying lethal/toxic substances— full radiography is mandatory. Generally, double welded butt joints are used. Structural steels such as/N226/2062 are not allowed. Only IS 2002 GrA (boiler quality steel) is allowed for construction. 

ASTM A 572, Specification for High-Strength Low-Alloy Columbium-Vanadium Steels of Structural Quality... 

One of the major differences between boiler-plate st I and structural-plate steel is the "quality control dictated by. the number, and severity of test requirements. As far as chemical requirements are concerned, the principal difference expressed by ladle analysis is the more r ftrictive-limit place[Pg.78]

Scrap materials often can be put to good use. When using scrap, however, it is best to weld with a low-hydrogen E7016-18 type of electrode, since the analysis of the steel is unlikely to be known, and some high-carbon steels may be encountered. Low-hydrogen electrodes minimize cracking tendencies. Structural scrap frequently comes from dismantled structures such as elevated railroads, which used rivet-quality steel that takes little or no account of the carbon content. 

High strength structural Micro-alloyed steels (Ti, Nb, V,B, Zr), Quality steels... 

EXAMINATION OF THE KINETICS OF MAGNETIC PROPERTIES IN TEMPERING STRUCTURAL STEELS WITH SPECIAL REFERENCE TO ACTIVE INSPECTION OF THEIR QUALITY by E.S. Gorkunov and I.n. Batuklitina, Vol. 23, No.3, pp. 177-183... 

The composition of the film changes with potential and with the incorporation of both anions and cations. EXAFS data on the passive films grown on stainless steel or normal steel with Cr04 show considerable incorporation of Cr into the film with further alterations in bond lengths and covalency parameters. Indeed, as the amount of Cr incorporated increases, so does the flexibility of the structure. It is well known, by contrast, that Cl incorporation leads to poorer quality films and to enhanced rates of corrosion. 

Magnetic particles may form much more stable beds when subjected to a magnetic field. Saxena and Shrivastava(51) have examined the complex behaviour of spherical steel particles of a range of sizes when subjected to fields of different strengths, considering in particular the bed pressure drop, the quality of fluidisation and the structure of the surface of the bed. 

Superplasticizers have been used successfully to achieve savings in concrete consolidation in heavily reinforced precast concrete sections, e.g. the high-quality finish required for the precast tube elements (carrying the mechanical and electrical services) used in the construction of the Montreal Olympic Stadium was achieved through the use of a superplasticizer. Fig. 7.41 shows the high density of steel reinforcement used in these structures. 

The Bessemer process is relatively less expensive but does not produce a product of high quality. It is not possible to exercise control over the composition of the product because the conversion occurs so quickly. Furthermore, this process does not effect the removal of phosphorus. The phosphorus pentoxide that is formed during the blow is reduced to phosphorus upon addition of carbon and hence remains as an impurity in the final product. Provision for the removal of phosphorus may be made by the use of the so-called basic Bessemer process, which employs a converter lined with magnesia (MgO), but this practice entails other disadvantages. In the United States, the acid Bessemer process is used exclusively and accounts for about 15% of the steel produced in this country. Steel so produced is used largely as structural steel, as reinforcement for concrete, and in the tinplate industries. 

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