大型球磨机干磨用高性能磨球的等温淬火工艺研究
毕业论文关键字：高性能磨球；等温淬火；下贝氏体；工艺；温度；
Abstract High performance grinding ball mill is widely used in metallurgy, mining, building materials, chemical industry, thermal power and other industries ball mill. The grinding ball is the grinding medium in the ball mill, which is used to crush the material in the mill. Rolling steel ball has the highest production efficiency and good performance. The usual rolling steel ball, directly after the rolling process of water quenching, and low temperature tempering, get more than HRC60 high wear resistant steel ball, this kind of steel ball in the wet grinding condition showed excellent wear resistance. But because of the poor stability of martensite obtained by the quenching of the low alloy steel, with the increase of temperature, the hardness decreased obviously, which makes the rolling and water quenched steel balls do not adapt to the dry condition. This paper is research of austempering process of system and trying to obtain lower bainite isothermal quenching, lower bainite has more excellent than martensite microstructure stability, its hardness with the tempering temperature changes a little. This paper selects production for small ball rolled B2 steel as raw materials, low melting point compound salt, molten salt as the isothermal quenching medium and study of the system of lower bainite B2 steel at different temperature after isothermal quenching microstructure and properties; of isothermal quenching of body tissue, series tempering tempering stability research and analysis of the dry grinding application feasibility conditions. The results show that the acicular bainite tissue obtained at 280 ℃ austempering and number, uniform distribution, to reach the hardness wear resistant steel ball on the performance index requirements, after tempering, microstructure changes little, still lower bainite mainly, back to the fire after the hardness despite the decline, but still can meet the requirements of wear resistant steel ball on the performance index. After tempering in the range of 260~320 ℃, the microstructure of the samples changed from martensite to tempered martensite, and the hardness was greatly decreased.
Keywords: High performance grinding ball; isothermal quenching; lower bainite; process; temperature;
上一篇：金属纳米晶体超导温度的热力学研究