国产T23钢焊缝区显微组织分析

Analysis on Microstructure in Weld Zone of Domestic T23 Steel

对国产T23钢焊条电弧焊接头焊缝区显微组织进行了研究。结果表明，根部焊道焊态下的组织由等轴铁素体和粒状贝氏体组成，经740℃和760℃回火后为粒状贝氏体和条状铁素体组织，在其基体上有弥散分布的点状析出物。覆盖焊道焊态下组织由粒状贝氏体和少量铁素体组成，740℃和760℃回火时为回火贝氏体组织，在690～740℃回火后形成少量聚集的粒状物，当回火温度为760℃时该粒状物分解、消失。过热区焊态下的组织由粒状贝氏体和条状马氏体组成，回火温度在690～740℃时，晶界显现，晶粒有所长大，并有大量粒状物在晶界处出现；经760℃回火处理后，原奥氏体晶界模糊、不连续，表现为回火贝氏体和回火索氏体组织，尺寸不一的点状析出物分布于基体上。

In the condition of tungsten insert shielded metal arc welding technology, the microscopic structure in the welding zone of T23 heat-resisant steel was researched. The results show that the microstructure of the root pass is equiaxed ferrite and granular bainite as welded, when tempered at 740 ℃ and 760℃, the microstructures is constituent by needle ferrite and granular bainite, and disperse paricle precipitate at the matrix. The microstructure of the covering beads is granular bainite and ferrite as welded, a minimum of granular structure appears when tempered at 690-740 ℃, and decomposes or disappears when tempered at 760℃; the microstructure is tempered bainite when tempered at 740-760 ℃. The microstructures of the coarse grain heat affected zone （CGHAZ） is granular bainite and lath martensite as welded, when tempered at 690-740℃, the grain boundaries appear obvious, the grains grow up, and a large number of particles appear at the grain boundaries; the grain boundary has discreted when tempered at 760 ℃, the microstructure is tempered bainite and tempered sorbite, there are spot precipitates of different sizes at the matrix.