12Cr1MoVG铁素体形态黄块组织研究

厚壁12Cr1MoVG锅炉用管在正火处理过程中,由于壁厚较厚会导致冷却速度下降,从而产生以铁素体和珠光体及少量贝氏体为主的组织,在此类组织中存在形态类似于铁素体的黄色块状组织,往往被误认为是不同位向的铁素体或是黄块马氏体组织。根据金相组织,结合CCT曲线、显微硬度及扫描电镜,对铁素体形态黄块组织进行了分析。结果表明,12Cr1MoVG中的铁素体形态黄块组织为未完全转变的贝氏体组织,在光学显微镜下因为析出相的细小而无法分辨,并且由于光的散射现象而呈现黄色表象。

Study on 12Cr1MoVG Ferrite-like Yellow Massive Structure

During the normalization treatment of 12Cr1MoVG boiler pipe, the cooling speed dropped due toits big wall thickness and therefore the structure dominated by ferrite, pearlite and small amount of bainiteformed. There existed in the structure a kind of yellow massive structure similar to ferrite, which was oftenmistakenly considered to be ferrite of different orientation or yellow massive martensite. The said structurewas analyzed with metallographic structure inspection in combination with CCT curve, microhardness andelectronic scanning microscope. Inspection results showed the ferrite -like yellow massive structure in12Cr1MoVG steel was bainite structure which had not transformed completely. Because the precipitatedphase was too fine to distinguish under the optical microscope, it presented to be yellow because of lightscattering.