| The 38B3 steel is a principal raw material for transmission bearing in cars. Recently, through improving the production flow and technological process, successfully developing the normalizing and peeling steel products, it can not only obtain a better product quality, but also increase the efficiency of production and utilization ratio of steel products. It is notable in the economic performance and social cost-benefit.In this thesis, not only the temperature control during rolling, but also the cooling control after rolling was studied. Through analyzing the mechanical property and micro-structure, researching the influence of processing parameters on the micro-structure and property, and at last, obtaining an appropriate rolling and cooling technology.The results are included that:(1) Because of less of water block at production line, normalizing treatment is used, uniform crystal grain, increasing HB and decreasing the percentage composition of ferrite.(2) The results indicate that:normalizing on line, because of the water block, the micro-structure under rolling and cooling technology, owning less percentage composition of ferrite and grain thinner, compared with the 38B3 steel produced by traditional technology.(3) The technology of 38B3 steel is mainly controlling RSB temperature and cooling temperature. Through controlling the processing parameter and temperature, normalizing on line becomes available. The hardness is medium value, grain size 7-8 level, and yield strength is more than 20MPa.(4) In the 38B3 steel, the Al,Cr,Mo elements narrow the austenite, meaning enlarging the area of non-recrystallization, rolling at this area becomes available. It is advantage to control the cooling temperature.(5) The technology application of 38B3 steel reduce cost more than 200rmb/t because of cancel the normalizing treatment off line.
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