Nightside inclined-vertical-butting welding method

A nightside inclined-vertical-butting welding method, characterized in that the method comprises the following steps of:

• providing a weldment and a welded plate to which the weldment is to be welded, wherein an end of the weldment to be welded to the welded plate is provided with a first welding face and a second welding face, the first welding face and the second welding face form a pointed cone, a tip position of the pointed cone is defined as an inner side, the space between the first welding face and the welded plate is a first welding area, and the space between the second welding face and the welded plate is a second welding area;
• in the first welding area, the weldment and the welded plate being welded at the innermost side of the pointed cone to form a first welding pass;
• in the second welding area, the weldment and the welded plate being welded at the innermost side of the pointed cone to form a second welding pass, and then welding being performed at the outer side of the second welding pass to form a third welding pass adjacent to the second welding pass;
• in the first welding area, the weldment and the welded plate being welded at the outer side of the first welding pass to form a fourth welding pass, and then welding being performed at a position adjacent to the fourth welding pass to form a fifth welding pass;
• in the second welding area, the weldment and the welded plate being welded adjacent to the outer side of the third welding pass to form a sixth welding pass,
• wherein the method further comprises a preheating step, and the width of the preheating range is selected to be 150 mm, wherein the preheating step comprises preheating to 30-50 degrees within 75 mm on both sides of a weld joint when the outside temperature is below 0 degree.