Structural materials austenitic stainless steels

The selection of materials for high-temperature applications is discussed by Day (1979). At low temperatures, less than 10°C, metals that are normally ductile can fail in a brittle manner. Serious disasters have occurred through the failure of welded carbon steel vessels at low temperatures. The phenomenon of brittle failure is associated with the crystalline structure of metals. Metals with a body-centred-cubic (bcc) lattice are more liable to brittle failure than those with a face-centred-cubic (fee) or hexagonal lattice. For low-temperature equipment, such as cryogenic plant and liquefied-gas storages, austenitic stainless steel (fee) or aluminium alloys (hex) should be specified see Wigley (1978). 

Using the triple-ion beam irradiation apparatus, the microstructural evolution of austenitic stainless steel, which is considered as a structural material for water-cooled fusion reactors... 

This family of stainless accounts for the widest usage of all the stainless steels. These materials are nonmagnetic, have face-centered cubic structures, and possess mechanical properties similar to the mild steels, but with better formability. The AISI designation system identified the most common of these alloys with numbers beginning with 300 and resulted in the term 300 series stainless. Table 3 lists the chemical analyses of some standard austenitic stainless steels and compares them to a few materials from other families of materials. 

Thermomechanical processing (TMP) has first been developed in the second half of the last century for decreasing the ductile to brittle transition temperature of construction steels. It has then progressively been extended to other categories of structural metallic materials, such as titanium alloys or nickel base superalloys for aircraft forged turbine parts. More recently, investigations have been carried out to assess the possibility and advantage of TMP for ferritic and austenitic stainless steels. 

L Zhang, M Wen, M Imade, S Fukuyama, and K Yokogawa, Effect of nickel equivalent on hydrogen environment embrittlement of austenitic stainless steels at low temperatures , in Eracture of Nano and Engineering Materials and Structures, Alexandroupolis, Greece, 2006. 

One material that has wide application in the systems of DOE facilities is stainless steel. There are nearly 40 standard types of stainless steel and many other specialized types under various trade names. Through the modification of the kinds and quantities of alloying elements, the steel can be adapted to specific applications. Stainless steels are classified as austenitic or ferritic based on their lattice structure. Austenitic stainless steels, including 304 and 316, have a face-centered cubic structure of iron atoms with the carbon in interstitial solid solution. Ferritic stainless steels, including type 405, have a body-centered cubic iron lattice and contain no nickel. Ferritic steels are easier to weld and fabricate and are less susceptible to stress corrosion cracking than austenitic stainless steels. They have only moderate resistance to other types of chemical attack. 

Their use may have a significant impact on the cost of a structure. The cost of the material has decreased in recent years and further reductions are expected, due to new developments in production, but stainless-steel bars are still much more expensive than carbon-steel ones. The following indications can be provided if 1 is the cost of carbon steel bars, 304 austenitic stainless-steel bars costs 6-8, and 316 and 318 (duplex) cost 9-10 [5,6]. 

Figure 1.17 shows SCC of a 2205 DSS sand separator cone in a pulp mill [49]. Duplex stainless steels possess a high-threshold stress intensity value, The duplex stainless steels that contain ferrite and austenite phases have better localized corrosion resistance than single-phase austenitic stainless steels in chloride-containing solutions and are used as structural materials in petrochemical, chemical, pulp and paper, power generation, oil, and gas industries. 

Contamination of austenitic stainless steels of the 300 type by compounds which can alter the physical or metallurgical structure and/or properties of the material is avoided during all stages of fabrication. Painting of 300 series stainless steels is prohibited. Grinding is accomplished with resin or rubber-bounded aluminum oxide or silicon carbide wheels which were not previously used on materials other than austenitic alloys. Outside storage of partially-fabricated components is avoided and in most cases prohibited. Exceptions are made for certain components provided they are dry, completely covered with a waterproof material, and kept above ground. 

The structural materials of the spent fuel storage racks must be able to withstand the temperatures and pressures present in the SFP. Additionally, in PWR SFPs, where boric acid (soluble boron) is used to augment criticality safety, the acidic environment must be considered. Therefore, the primary structural material in use in the majority of spent fuel racks is austenitic stainless steel. 

Gebeau, R. C. and Brown, R. S Corrosion Resistance and Strength of Biodur 108 Alloy, A Nickel-Free Austenitic Stainless Steel, Structural Biomaterials for the 21st Century, M. Niinomi, et. al. Ed., The Minerals, Metals and Materials Society, 2001, pp. 157-164. 

Dong, H., Qi, P.-Y., Li, X. Y. and Llewellyn, R. J. Improving the erosion-corrosion resistance of AISI 316 austenitic stainless steel by low-temperature plasma surface alloying with N and C, Materials Scienoe and Engineering A Structural Materials Properties, Microstructure and Processing (2006) 431,137-145... 

The excellent performance of austenitic stainless steel in normal atmospheres combined with the possibility to spot-weld this structural material, tempted a major manufacturer of stainless steel trains in the United States to bid for a contract to build two hundred all-stainless steel air freighters to carry troops, tanks, and guns during the World War II efforts. In fact, the first entry of the Budd Company in the world of aeronautics was made in 1930 through the contract manufacture of aircraft wheels and stainless steel wing ribs, following which a complete aircraft was designed and built by the company in 1931, the BB-1 Pioneer amphibian (Fig. 9.48). 

Structural materials Claddings of fuel elements - ChS-68hd steel (06Cr 16Ni 15Mo2Mn2TiB). Reactor stmctures - Crl8Ni9 austenitic stainless steel. ... 

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