【摘要】 本文给出了1200℃以下钢的纵波声速随温度变化的关系曲线,讨论了在加热与冷却过程中声速变化的规律性与声速滞后现象产生的原因是由于相变及其弹性系数比晶内小的晶界对质点位移的影响。同时指出这种现象的发现有利于透过声同物质的相互作用来研究奥氏相变,并有可能借助于声速-温度曲线推断出该种钢的奥氏相变温度,特别是A_r1和A_r3。本文所得结论,在高温钢坯超声检测中对缺陷定位及避开声速随温度发生陡变区域有重要指导意义。更多还原

【Abstract】 In this paper the curves of longitudinal wave velocity in steel versus temperature from room temperature to 1200C are given Th velocity variation with temperature on heating and cooling is discussed and the effect of the au tenite transformation and interfaces of grains with coefficient of elasticity less than it in grains on p rticle displacement is explained as the reason to cause the hysteresis phenomenon here. At the sam time, the discovery of the hysteresis is useful to investigate microcosmic process in austenite transf rmation through interreaction between sound and material crystal structure. Pointing out that the austenite transformation temperature can be deduced from the curves obtained, especially Arl and A 3. In addition, the results obtained are also significant guidance for precisely determining the flow position and avoiding the temperature region in which the velocity varies drastically in ultraso ic testing of hot steel b’ooms and slabs.更多还原