新型高强钢多层焊HAZ的组织计算

根据新型高强钢经受不同热循环后的组织变化规律，建立了新型高强钢多层焊焊接热影响区（HAZ）的数值计算模型。编制了其HAZ中局部脆性区（LBZ）尺寸及百分比的计算程序。作为结果验证，计算了WEL-TEN780A新型高强钢多层焊的HAZ中LBZ的百分比，计算值与实测 值吻合良好，其最大误差为6.69%，在此基础上，本文以影响LBZ的主要因素进行了讨论，计算结果表明，新型高强钢多层焊HAZ的薄弱环节位于距熔合线2～0.5mm处，焊接线能量对LBZ的影响具有一定的阶段性，但总的来说，大约20kJ/cm的线能量对于减少LBZ是有利的，预热也有利于减少LBZ，另外，降低特征温度T1和提高特征温度T3也有利于预防LBZ 。

The Microstucture Calculation in the HAZ of Multipass Welds of New Type High Strength Sted

In this paper, the authors have established a numerical calculation model of the HAZ of multipass welds of a new type high strength steel, according to the various structure of the new type high strength steel after varied heat circle. and calculated the size of local brittle zone (LBZ) in its HAZ. The calculated results accord well with the measured ones, the maximal error is 6. 69%. Based on what had been done, this paper discussed that main factors that influence LBZ. The results indict that: The weak POsition of the HAZ of multipass weds of new type high strength steel is 0. 2 0. 5mm from fusion line; The influence of welding linear energy on LBZ is seasonal, but generaly speaking, the linear energy about 20kJ/cm is advantaged to reduce LBZ; And preheat is advantage to reduce LBZ, and decreasing character temperature T1 and T3 are also helpful to prevent the happening of LBZ.