根据断口的宏、微观形貌，认为油管焊接后未及时消除焊接应力，产生了淬硬裂纹；
The macro and micro analysis of fracture indicates that it produces fracture because it doesn′t avoid welding stress in time.
详细介绍了主要受压件的焊接工艺、整体消除焊接应力热处理技术以及关键的检验控制点。
The welding procedure of main pressure parts , its bulk heat treatment and checking point are detailed.
首次在锤击消除焊接应力的数值模拟研究中，采用接触单元技术建立有限元模型模拟计算锤击作用。
In the numerical simulation of relieving residual stress by hammer peening, contact element technique was firstly adopted for establishing the finite model and calculating the hammer peening.
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