齿条板对接焊变形计算及控制方法

摘要

Rack board are the important modular of jack-up drilling unit's legs and it is important to predict and control the welding deformation of rack boards whose welding requirement is very harsh. In this paper, a mechancial model of butt-welding deformation of rack boards involving the main influence factors of welding deformation is constructed based on some reasonable hypothesis. Two cases in which heat input are 15 kJ/cm and 50 kJ/cm respectively are calculated using this model with different number of welding layer once. The results reveal that all the final values of angular deformation meet the required welding precision in three cases with different number of welding layer once. This is due to the correction function of both sides in the welding process. The correction of both sides may cause the weld-seam crack so that we suggest conservatively welder to do the butt-welding of rack boards by welding with one welding layer once. In the actual welding process, that is alternate two layers of both sides.%齿条板是自升式钻井平台桩腿的重要模块，其焊接工艺要求相当苛刻，焊接变形的预测与控制是一项十分重要的工作。为此，在一些合理的基本假定基础上，考虑焊接变形的主要影响因素，建立起齿条板对接焊变形计算的力学模型，并分别对热输入量为15 kJ/cm和50 kJ/cm两种工况下不同单次焊层数进行计算。结果发现，针对三种不同单次焊层数的情况，其最终角变形量都满足焊接精度要求。必须看到，这是由焊接过程中双面矫正作用所导致的结果，而这种矫正作用可能会导致焊缝开裂。所以经过计算，建议齿条板对接焊应采用单次焊层数为1层，即上、下交替焊接2层的焊接工艺。