China
Africa
Explore chapters and articles related to this topic
*
Published in Tom Bell, Katsuya Akamatsu, Stainless Steel 2000, 2020
Austenitic stainless steels have good corrosion resistance in many environmental conditions, but they have low hardness and poor friction and wear properties. Attempts have been made to develop surface engineering techniques for improving these properties.1 However, surface modification of austenitic stainless steels usually presents two major problems. One problem is the formation of an oxide scale (Cr2O3) on the steel surface owing to the strong affinity of chromium, which is the main alloying element in austenitic stainless steels, with oxygen in air. This oxide scale frequently results in poor adhesion between a coating and the steel surface.1 Therefore, such surface modification techniques as PVD, electroplating and electrolysis plating have limitations for stainless steels, compared with coating and plating of other ferrous alloys.
Ferrous and non-ferrous metals
Published in Arthur Lyons, Materials for Architects and Builders, 2019
Stainless steel is available in square, rectangular, oval and circular hollow sections, as well as the standard sections for structural work. It is widely used for roofing, cladding, interior and exterior trim, owing to its combined strength, low maintenance and visual impact (Fig. 5.22). Stainless steels for self-supporting profile sheet and tile roofing systems are listed in BS EN 508-3: 2008. A minimum thickness of 0.4 mm is specified in pr EN 14782: 2015 and long-strip roofing to 15 m is possible due to the fatigue resistance and moderate coefficient of expansion. The standard also lists optional organic finishes, including polyester, silicone-modified polyester, polyurethane, polyvinylidene fluoride and PVC plastisol. The corrosion resistance of stainless steel also makes it eminently suitable for masonry fixings, such as corbels, anchor bolts, cavity wall ties and for concrete reinforcement. Austenitic stainless steels are used for the manufacture of pipework, catering, and drainage products where durability and corrosion resistance are critical. Exposed exterior stainless steel should be washed regularly to retain its surface characteristics, particularly where a brushed rather than polished finish has been used. Pitting corrosion causing surface pin-point attack, crevice corrosion under tight-fitting washers and stress corrosion cracking, where the material is under high-tensile load, may occur where inappropriate grades are used in aggressive and marine environments.
High Alloy Steels
Published in P. C. Angelo, B. Ravisankar, Introduction to Steels, 2019
The temperature and incubation time for chromium carbide formation (time for sensitization) is depended on the amount of carbon in the austenitic stainless steels. For example, in austenitic stainless steel with 0.06% C (normal 304 grades), the chromium carbides start precipitating from 475 to 850°C and the time varies between 1 min to 100 h depending on the temperature which is called as sensitization zone where as for austenitic stainless steel with 0.02% C sensitization zone is between 475 to 580°C and time is above 100 h. Care has to be taken while using the austenitic stainless steel at high temperatures and also during welding by ensuring that the alloy is not cooled slowly in the sensitization temperature range. Even the austenitic stainless steels should be quenched from annealing temperature even for annealing is called as quench annealing.
Parameters effect on SS304 beads deposited by wire arc additive manufacturing
Published in Materials and Manufacturing Processes, 2020
D.T. Sarathchandra, M. J. Davidson, Gurusamy Visvanathan
In the present work, austenitic stainless steel grade SS 304 was used for experimental studies. Austenitic stainless steels are extensively used in nuclear applications such as reactor coolant pipes, valve bodies, spacer column assembly, control rod drive mechanism, and vessel internals.[16,17]Many input factors contribute directly or indirectly to material performance characteristics in the WAAM process. These include input power, weld travel speed, wire feed, standoff distance, inert gas flow rate, path planning, deposition strategies, etc. The present study considers the effect of input power in terms of current, travel speed, and standoff distance on the clad bead properties such as bead shape, size, and depth of penetration.
Effect of latter feeding wire on double-wire GTA-AM stainless steel
Published in Materials and Manufacturing Processes, 2021
Austenitic stainless steel has been extensively applied in chemistry production, aerospace, and nuclear reactor engineering structures owing to its superior corrosion resistance as well as mechanical properties.[1,2] At present, stainless steel components are mainly produced by conventional machining, casting, and forging technologies. However, these methods possess complex manufacturing processes and may lead to a long production cycle or a high buy-to-fly ratio. Therefore, increasing demand from the modern industry calls for an innovative fabrication method to achieve higher manufacturing efficiency and material utilization rate than the traditional technologies, especially for building large-scale stainless steel structural parts.
Grain refinement and strengthening of austenitic stainless steels during large strain cold rolling
Published in Philosophical Magazine, 2019
Marina Odnobokova, Andrey Belyakov, Rustam Kaibyshev
Austenitic chromium-nickel steels are one of the most important and frequently used stainless steels because of their good combinations of ductility, toughness, formability, weldability and corrosion resistance [1]. The most widespread representatives of the austenitic stainless steels are types of 316 L/304 L steels. The conventional heat treatment of austenitic steels consisting of solution treatment at 1273–1373 K followed by rapid cooling results in a carbide-free microstructure with a homogeneous distribution of the alloying elements that provides excellent corrosion resistance. On the other hand, austenitic stainless steels with well annealed/recrystallized microstructures exhibit relatively low yield strength [2]. The yield strength can be increased by cold working, which is commonly accompanied by strain hardening, deformation twinning and strain-induced martensite. The deformation microstructures and the dislocation densities in the cold worked steels depend on stacking fault energy (SFE) [1,3,4]. Austenitic stainless steels are characterised by relatively low SFE ranging from approx. 20 mJ/m2 to 50 mJ/m2 [5]. Low SFE promotes the partial slip and, therefore, suppresses dynamic recovery. Following rapid increase in the dislocation density, the deformation twinning and the strain-induced martensitic transformation may occur in austenitic stainless steels during cold deformation. The strain-induced martensite readily develops in deformation micro-shear bands, which result from in-grain localisation of the plastic flow, or deformation twins and, especially, at twins/microbands intersections [6,7]. The frequent deformation twinning and strain-induced martensitic transformation during cold working of austenitic stainless steels result in subdivision of original microstructures into ultrafine crystallites with a size of below 0.1 μm [8–12]. Such microstructure refinement along with high dislocation density in the cold worked steels provides substantial strengthening. The strength of cold worked stainless steels may exceed 2 GPa [8,10,13–16].