This book describes the welding job and associated procedures and methods in a simple language with images to illustrate the whole process as applied to the oil gas field pipelines. The book is mainly for the welders working in the oil gas fields.

三维双椭球热源在平面问题中的实现，可用于模拟焊接过程-3D double ellipsoid heat source in the plane in question to achieve, can be used to simulate the welding process