CAJ | 학술논문

将含Cu-Cr微合金钢930℃保温30rain淬火至室温，随后650℃回火10min-10h。利用光学显微镜（0M）和透射电子显微镜（TEM）研究不同回火时间条件下，样品中组织演变和第二相析出行为。结果表明：回火过程中组织从马氏体和贝氏体逐渐向针状铁素体和多边形铁素体演变；硬度变化曲线上出现2个二次硬化峰值，分别为回火1h和4h时的硬化峰，前者是V和Mo的碳化物析出强化结果，后者是由富Cu相的析出强化所致，V和Mo的碳化物强化产生的硬度值增量大于富Cu相；Cr的碳化物在回火过程中析出长大速度较快，析出强化能力较弱。
장함Cu-Cr미합금강930℃보온30rain쉬화지실온，수후650℃회화10min-10h。이용광학현미경（0M）화투사전자현미경（TEM）연구불동회화시간조건하，양품중조직연변화제이상석출행위。결과표명：회화과정중조직종마씨체화패씨체축점향침상철소체화다변형철소체연변；경도변화곡선상출현2개이차경화봉치，분별위회화1h화4h시적경화봉，전자시V화Mo적탄화물석출강화결과，후자시유부Cu상적석출강화소치，V화Mo적탄화물강화산생적경도치증량대우부Cu상；Cr적탄화물재회화과정중석출장대속도교쾌，석출강화능력교약。
Abstract:Optical microscope (OM) and transmission electron microscopy (TEM) were applied to in- vestigate the microstructure and the second phase precipitation in a Cu-Cr-bearing microalloyed steel tempered at 650℃after solution treatment at 930 ℃ for 30 min. The results indicated that martensite and bainite evolved to acicular ferrite and polygonal ferrite gradually during the tempering process. Two hardness peaks appeared with the sample tempered for 1 h and 4 h, corresponding to the precipitation strengthening effect of the V-Mo contained carbide and the Cu-rich phase, with the hardness increment generated by the carbide higher than that by the Cu-rich phase. The Cr-contained carbide grew faster during the tempering process, so that the precipitation hardening ability was weak.