Research on Microstructure and Properties of Spray Formed Corrosion and Wear Resistant Steel HSF340

    
    Introduction
    
    Spray forming is a process used to manufacture components with near-net high precision by using a spray of molten metal. This process is used in the production of alloys such as tool steel, stainless steel and aluminum alloys. It can be used to produce special purpose components with complex shapes and good surface finish. This process offers great advantage over other processes such as casting, casting and forging. One such alloy is an advanced high speed steel known as HSF 340. This alloy offers superior corrosion and wear resistance and is used in various industrial applications due to its superior properties. This article aims to investigate the microstructure and properties of spray formed HSF 340 corrosion and wear resistant steel.
    
    Microstructure and Properties of HSF 340
    
    HSF 340 is an advanced high speed steel with superior corrosion and wear resistance. The alloy consists of 0.9-1.0% carbon, 13-14.5% chromium, 2.4-2.6% vanadium, 5-5.5% tungsten, 0.7-1.1% molybdenum, and 0.45-0.55% manganese, and traces of other elements. It is a martensitic structure with good hardenability, toughness and tempered stability. It has excellent wear resistance at high temperatures and also exhibits good corrosion resistance properties.
    
    The microstructure of spray formed HSF 340 consists of an acicular ferrite (AF) matrix and second-phase carbides precipitated within the AF matrix. The AF matrix consists of lath-shaped grains which are mixed with some minor pearlite, bainite and martensite. The carbides are mostly M7C3 type with some M6C, M23C6 and M2C. The AF martensite grains are refined and well distributed due to the rapid solidification which results in good mechanical properties and wear resistance.
    
    The mechanical properties of spray formed HSF 340 steel have been studied by several researchers. The results from these studies have shown that the alloy has a high strength and good wear and fatigue resistance. It has a tensile strength of up to 2000 MPa and a yield strength of up to 1500 MPa. The alloy also has an excellent toughness, with a high impact toughness of up to 160J. Further, the alloy also exhibits high hardness (up to HRC 70) and excellent wear resistance due to the presence of hard-second phase carbides.
    
    The corrosion resistance of spray formed HSF 340 steel has also been studied by several researchers. The results from these studies have shown that the alloy exhibits excellent corrosion resistance in various environments. In acidic conditions, the alloy shows a corrosion rate of less than 0.1mm/year. Further, in non-oxidizing saline environments, the alloy shows a corrosion rate of less than 0.3mm/year. The alloy also exhibits excellent resistance to crevice and pitting corrosion.
    
    Conclusion
    
    HSF 340 is an advanced high speed steel with superior corrosion and wear resistance. The microstructure of the alloy consists of an acicular ferrite (AF) matrix and second-phase carbides precipitated within the AF matrix. The alloy has been studied for its mechanical and corrosion resistance properties, and it has been found to have high strength, good wear and fatigue resistance and excellent corrosion resistance. The excellent properties of spray formed HSF 340 make it suitable for use in many industrial applications.

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