【摘要】 以07MnNiMoVDR钢为研究对象,通过热膨胀试验、TEM检测相结合的方法,研究其回火过程中各回火温度区间中组织转变和碳化物析出的变化规律.结果表明:300℃回火时,残余奥氏体分解,片状θ-碳化物位于仍具有较高位错密度的α相板条之间;650℃回火时,α相除回复外,部分α相还发生了再结晶,析出物分布于已回复的板条之间以及再结晶晶界上.更多还原

【Abstract】 The 07MnNiMoVDR steel for low-temperature pressure vessel was investigated via thermal expansion testing in combination with TEM detection for the transformation of microstructure between different temperature intervals and change of carbide precipitation in the tempering process.The results showed that when the specimens are tempered at 300 ℃ the residual austenite is decomposed and the lamellar θ-carbides are found between α-phase laths which are still of relatively high dislocation density.When tempered at 650 ℃,the α-phase laths are recovered with part of them recrystallized.Moreover,the precipitates are distributed between the recovered α-phase laths and on the recrystallized grain boundaries.更多还原