The relationship between stainless steel seamless pipe and stainless steel welded pipe is interrelated. The question is how to properly position the relationship between the two and find a common development direction.
From the current level of domestic stainless steel welded pipes, it is difficult to connect them with the standard of stainless steel seamless pipes. However, as a development direction, it should be clarified because many pipes made of stainless steel welded pipes are now replaced by stainless steel seamless pipes. Once the level of stainless steel welded pipes increases, this part of the market should return to stainless steel welded pipes. It is very important to comprehensively compare production capacity, labor productivity, and various technical and economic indicators.
Based on the problem of standard materials (strip or coil), from the perspective of the stainless steel welded pipe production plant, whether it can be integrated with stainless steel seamless pipe, that is, to replace stainless steel seamless pipe with stainless steel welded pipe, we think it is:
1. The seamless hot-rolled parts (the tube is heated to the rolled pipe) and the molded parts of the stainless steel welded pipe belong to the steel pipe forming device, but the adaptability of the processed products is different. For pipes with larger wall thickness and outer diameter, more hot perforations are used, making it more difficult to form stainless steel welded pipes. The key point is that the later process is mainly to reduce the diameter of the process. If there is no fixed diameter, the specifications of the pipeline will be restricted and the output will be restricted. In terms of seamlessness, the finished product can only be produced by repeated cold drawing and processing. Stainless steel welded pipe can only be solved by changing the hole type, so that the most economical and convenient strip can be cut to meet the specifications. If the post-weld process of the stainless steel welded pipe is established, the stainless steel welded pipe will be established.
2. The round billet currently developed adopts continuous casting and arc casting technology, which reduces the production cost of stainless steel seamless pipes and the price is competitive. Low alloy steel can reach the price ratio of continuous casting billet and rolled parts: if using double-flow or multi-flow continuous casting, the ratio can reach 1: 1.25 or more. High-alloy steel and medium- and small-diameter thick-walled pipes can only be processed by seamless production methods due to difficulties in processing. Stainless steel welded pipes are difficult to adapt. In this regard, stainless steel seamless pipes have an unshakable position. With the improvement of technology and improvement of equipment, there will be good development.
3. The grade improvement of stainless steel welded pipe products should start from steel-making steel plate. Regardless of whether the hot rolled coil is a cold rolled coil, the performance of the steel form should be consistent with that of the stainless steel seamless billet. With the continuous use of stainless steel seamless tube billets for continuous casting, the refining of steel improves the precision of steel and greatly improves the purity of steel.
