In recent years, the rapid development of production technology and equipment technology level of global stainless steel pipe, stainless steel pipe international advanced production features is the use of new equipment, new technology, automatic control and NDT to improve product quality and yield, in the domestic stainless steel welded pipe and seamless steel pipe production technology have also made great progress, but compared with the international advanced level there is a large gap. Below to look at the production technology of several stainless steel pipes.
Three step process for steelmaking and continuous casting
The production of stainless steel pipe billet by “three step” steelmaking and continuous casting can effectively increase the quality of stainless steel pipe billet and reduce the cost. The process of using electric furnace for melting, MRP – L converter and oxygen gun fast decarbonization, VOD vacuum furnace end deep decarburization, the starting point is that the advantages of AOD and VOD two kinds of production process of the combination of play, can solve the large consumption and processing time for the shortcomings of AOD argon and refractory materials, a short time with the aim of low cost.
Hot extrusion process
Hot extrusion process is the main production process of hot – working stainless steel seamless steel pipe. With the continuous development of technology, some hot rolled steel pipe sets can produce stainless steel pipes, but the extruding unit is the main production unit of stainless steel seamless steel pipe. Compared with rolling and rolling, it is characterized by three direction compressive stress in the deformation process of stainless steel. In this optimal stress state, the stainless steel pipes with high deformation resistance can obtain a better quality of the internal and external surface and the metallographic structure.
Cold rolling production in cold rolling
Cold processing stainless steel pipes mainly use cold rolling (cold drawing) combined production technology, cold rolling mills and cold drawn machines develop towards high-speed, high-precision, long journey and multi line. Most of the stainless steel pipes are finished in the form of cold processing. So people pay more attention to cold processing equipment. Cold – drawing, cold rolling, cold – rolling and cold drawing are the three kinds of cold – processing technology. Cold rolling and cold drawing are used in most of the stainless steel pipes. The main and secondary relations are cold rolling and cold drawing. The modern cold rolling mill can also achieve large reducing and large wall reduction, and the deformation of the rolling mill is mainly achieved on the cold rolling mill. Multi line, high speed and full automatic are the better development direction of the current cold drawing machine.
Various welding processes
The progress of welding technology has speeded up the development of stainless steel welded pipe production, and the application of various welding methods further improved the welding quality and productivity. At present, the main methods for welding stainless steel used in industry are tungsten arc welding, high frequency welding, plasma welding and laser welding. The highest application frequency is argon arc welding and high frequency welding.
Light heat treatment process
Concerning the heat treatment process of stainless steel pipes, the non oxidation continuous heat treatment furnace with protective gas is widely used abroad for intermediate heat treatment and final product heat treatment. Because of the ability to get no oxidation of the bright surface, in order to eliminate the traditional pickling process. The use of this heat treatment process not only optimizes the quality of the stainless steel pipe, but also solves the problem that the acid cleaning is easy to pollute the environment.
Source: China Stainless Steel Pipe Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)