Конструкциялық материалдар және термоөңдеу Конструкционные материалы и термообработка Constructional materials and heat treatment Учебное пособие для специальности: 5В071200– «Машиностроение»
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montaev s h
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- Machine-building cemented alloyed steel
| Construction low-alloyed steel.
Construction low-alloyed steel with the raised content of manganese and silicon after hot rolling or heat treatment use for production of welded and riveted designs of construction farms, designs of bridges, frames, etc. Manganese steel of brands 19G and 14G apply to production of the main oil pipelines, steel 35XC, 25G2S-for production of fittings usual and previously the strained ferroconcrete designs. Low-alloyed steel after rolling considerably surpass in technical properties carbonaceous steel. The optimum combination of their properties is reached at introduction of several alloying elements. The designs operated at low ambient temperatures, carry out from steel, alloyed by nickel. Low-alloyed low-carbonaceous steel well cook. Properties of welded seams and sites adjoining to them are close to properties of the main metal. Became, used for welded designs, contain aluminum or the titan preventing integration of grain of metal in an weld-affected zone. The alloying copper, nickel, chrome, phosphorus promotes increase in corrosion resistance steel in air-gas and damp environments. Machine-building cemented alloyed steel. Steel of this group contain 0,1-0,3% of carbon and 0,2-4,4% of alloying elements. Operational properties of products from low - and medium alloy steel are defined by a combination of properties of a blanket and a core. Strength properties of a layer on a working surface of products are mainly caused by the content of carbon in it. On mechanical properties after heat treatment 199 (cementation) of steel of this group subdivide on medium solid (Gт≤700 of MPa) and there were the increased durability (Gт> 700 MPas). Cemented alloyed steel apply to production of the loaded details testing sign- variable and shock loadings (cogwheels, shaft, cams, etc.). Characteristic representatives of this group - steel 15HF, 15H, 20H-differ average durability. After training in oil the core of details from such is strengthened by the steel, but the surface is sensitive to cuts. Apply them to production of the small details operated at average loadings. To steel of the increased durability carry in a complex alloyed and economically alloyed. Steel 12XH3A, 20XH3A, 20XH4A apply to production of details of averages and the big sizes working in the conditions of intensive wear at raised loadings (cogwheels, piston fingers, axes, etc.). Especially responsible details - cogwheels of aviation engines, ship reducers - produce from steel 18X2H4MA, 18X2H4BA which it isn't enough soften at drawback. Economically alloyed steel of 18HGT, 30HGT, 25HGT is possible to replace the nickel chrome. Their main advantage is hereditary fineness that allows reducing a production cycle of processing of details. Such steel apply to production of responsible details of large-lot and mass production. жүктеу/скачать 1,99 Mb. Достарыңызбен бөлісу:
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