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Effect of Alloying Elements in Steel
Published in P. C. Angelo, B. Ravisankar, Introduction to Steels, 2019
When nitrogen is added to austenitic steels, it can simultaneously improve fatigue life, strength, work hardening rate, wear and localized corrosion resistance. High nitrogen martensitic stainless steel shows improved resistance to localized corrosion, like pitting, crevice and intergranular corrosions, over their carbon containing counterparts. Because of this, the high nitrogen steels are considered as a new promising class of engineering materials.
Structural Materials
Published in C. K. Gupta, Materials in Nuclear Energy Applications, 1989
Compositions of the various types of steel briefly described above are shown in Table 12. The AISI 300 series consists of austenitic steels. Type 304 is the general-purpose grade, widely used in application requiring a good combination of corrosion resistance and formability. Type 304 L is a lower-carbon modification of type 304 used in applications requiring welding. Types 316 and 317 contain molybdenum and have a greater resistance to pitting in marine and chemical industry environments. Types 321, 347, and 348 are grades stabilized with titanium, niobium and tantalum, and niobium, respectively. Type 348 is a nuclear-grade stainless steel having a restricted tantalum and cobalt content. Nickel-manganese-nitrogen stainless steels are the austenitic steels designated as the 200 series. The 400 series of AISI standard grades are ferritic. The 400 series of AISI with requisite compositions are martensitic types. They have an austenitic structure at elevated temperatures that can be transformed into martensite by suitable cooling to room temperature. Type 410 is the classic 12% Cr martensitic stainless steel and is the most popular martensitic grade produced today. It is used in many wrought forms, and in sand and investment castings. Type 420, with medium carbon, is the original cutlery grade. Types 414 and 431 contain nickel, which gives rise to somewhat higher toughness and corrosion resistance, and are used in aircraft fittings, pumps, and valves.
Machining of 7Cr13Mo steel by US-PMEDM process
Published in Materials and Manufacturing Processes, 2021
W. Zhang, L. Li, N. Wang, Y.L. Teng
7Cr13Mo steel is a martensitic stainless steel, which finds wide applications in stream generator gas turbines, compressors, medical devices and kitchen knives by cause of high strength and better corrosion resistance.[1,2] However, martensitic stainless steel is difficult to process and has poor wear resistance under harsh conditions.[3] To overcome the difficulties, electrical discharge machining (EDM) is a potential processing method. EDM is an essential non-conventional machining method in which a series of discharge sparks are generated between the electrodes to convert electrical energy into thermal energy.[4–6] It can machine hard materials even with complex geometrical shapes. While the inferior surface quality and low machining efficiency restrict its application.[7]
Surface and bulk modification techniques to mitigate silt erosion in hydro turbines: a review of techniques and parameters
Published in Surface Engineering, 2022
Recently, Mondal and associate researchers performed a quenching and tempering heat treatment (austenitized 900°C + hold for 10 min + water quenching + tempered at 300, 400, and 500°C for 1 h) on a low carbon martensitic stainless steel [107]. They compared the heat-treated steel with Hardox 400 steel for mechanical properties, microstructure, and erosion performance. The erosion resistance was found to be 3 times the counterpart of Hardox 400 steel. They identified hardness and strain hardening tendency as the deciding properties for the improved erosion performance. The erosion was caused by microcracks and craters which characterize a brittle mode of fracture.
Research on microstructural and property evolution in laser cladded HAZ
Published in Surface Engineering, 2021
Cunliang Pan, Xiaoqiang Li, Ruihua Zhang, Chao Lu, Chao Yang, Dengzhi Yao
Martensitic stainless steel is a chromium-containing stainless steel material that maintains a martensitic structure at room temperature. Proper heat treatment (quenching + tempering) results in high strength and abrasion resistance as well as a moderate corrosion resistance. Therefore, this material is useful in the manufacture of cutting and turbine blades, and bearings, among others [1–3]. Generally, the AISI420 stainless steel is constrained by its hardness, therefore, used to make ordinary kitchen knives, whereas the AISI440B and AISI440C materials are used to make premium kitchen knives [4–7]. Generally speaking, the harder the knife is, the sharper and more durable the knife will be, but its toughness will be poor at the same time. At present, the hardness of AISI440B and AISI440C materials were measured to between 500 and 580 HV after heat treatment. These materials are considered ideal for the knife. However, they are associated with high costs, processing difficulties and low yield [8]. The laser cladding technique which developed in recent years is an efficient surface-modified technique. For example, laser beam technology was used as the heat source to clad materials with different properties on the surface of a component, subsequently improving the substrate’s surface performance. Compared to the traditional surface coating technologies such as thermal spraying, arc welding and chemical heat treatment, laser cladding offers unique properties including low dilution, fast cooling rates and good metallurgical bonding [9–13]. Cladding the alloy powder with high hardness and excellent corrosion resistance on the surface of AISI420 steel provides the ordinary kitchen knives with an excellent performance, thereby effectively reducing production costs while improving the economic benefits [14, 15].