Welding Heat Cycle of Stainless Steel Welded Pipe

1, Stainless steel welded pipe in the welding process, with the welding arc gradually moving closer to a certain point, the temperature gradually increased. As the arc moves closer to this point, the temperature rises to its maximum. Followed by the electric gradual away from the point of the temperature is gradually reduced, and finally slowly slows down to room temperature. This roundworm hot cooling process at a point is called the welding thermal cycle at that point. Welding at different points of the welding heat cycle is not the same.

1. Stainless steel welded pipe in the role of welding heat cycle, the weld of two cases of base metal is actually in the golden session to withstand a rapid heating and cooling of the special heat treatment process, so its organization and performance will also change. This area under the effect of welding heat cycle changes in the organization and performance, known as the weld heat affected zone. HAZ has a certain width, its size and welding methods and specifications have a great relationship.
2. Stainless steel welded pipe heat affected zone in the water with the long position, due to the different welding heat cycle, its organization and performance are also different. In terms of mild steel, in the hot-reverberation area close to the weld, the maximum heating temperature of more than 1100 degrees, the grain particularly thick, poor plasticity and toughness, is the weakest link in the heat-affected zone, called coarse grain Area or overheating area. The heat-affected zone in the highest heating temperature of 900-11000 area, because the product pull very good plasticity and toughness, the area known as the fine grain or phase change recrystallization zone.
3. For low alloy and medium alloy high strength steel, medium carbon steel and high carbon steel easily hardenable steel heat affected zone, there are quenching zone (1400-900?) and part of the quenching zone (900-730?) points. In the quenched zone, the grain size of the coarse zone close to the weld is large, and the tendency of quenching is the most obvious, which is the part of the Guan Tian (weak area) that affects the performance of the heat affected zone. It is also the focus of studying the embrittlement behavior of the joint.

A worker from a steel pipe company, which is located in China.