Lately, the rolled stainless steel composite pipes made by Shougang Group were successfully put into service in the municipal water pipeline project of Shougang Park’s underground comprehensive pipe trench, symbolizing the success of China’s first large-diameter rolled stainless steel composite pipe test section for municipal water pipeline. This will provide strong technical support for Shougang Group to develop stainless steel composite products and has been a brilliant milestone for Shougang Group to be an urban comprehensive service provider.

With the improvement of people’s awareness in environment protection and safety, they are paying more and more attention to the safety and quality of tap water. Due to inside corrosion, conventional water distribution or delivery pipes tend to cause secondary pollution to water resource.. Pure stainless steel pipes have been widely used for tap water supply in developed countries, such as the US and Japan, but their overall cost is quite high. Stainless steel composite plate, being a new-type metallic composite, is made by cladding traditional carbon steel with a layer of stainless steel through rolling. As a result, the plate has both the toughness of carbon steel and the corrosion resistance of stainless steel, having significant cost performance. It not only is low in cost but also has better comprehensive mechanical properties when it is used in municipal water supply & drainage pipes and fire water pipes. It has a promising prospect in the field of municipal construction.

In order to improve the construction quality of Shougang Park and promote the application of stainless steel composite pipes in the field of municipal construction, by cooperating with Beijing General Municipal Engineering Design & Research Institute Co., Ltd., Beijing Shougang Construction Group Co., Ltd and other units, Capital Development Investment Fund Management Co., Ltd and Shougang Technology Institute have built a large-diameter 235B+304 stainless steel composite pipeline (1,020mm in diameter and 84m in length) for municipal water supply in the underground comprehensive pipe trench on East Liangshuichi Road of Shougang Park.Being the first large-diameter rolled stainless steel composite pipe test section for municipal water pipeline in China, it has provided opportunities for the  development and application of new stainless steel composite plates.

So far, the lacking of successful applications of rolled composite pipes in municipal water supply & drainage pipelines as well as corresponding national standards and technical materials has made the development and marketing of this kind of product become very difficult. Based on close cooperation with technicians of Qinhuangdao Shouqin Metal Materials Co., Ltd. and Qinhuangdao Shouqin Steel Processing & Distribution Co., Ltd and by learning from national standards and regulations, the composite plate R & D team of Shougang Technology Institute has developed internal technical specifications and site construction schemes which are applicable to producing rolled composite pipes with stainless steel. These specifications and schemes have provided clear technical requirements for the material and production of composite plates as well as the performance and anticorrosion mode of finished pipes. By repeatedly groping and verifying in multiple pilot plant tests, a range of technical problems, such as the fulfillment of combination and strength requirements, profile control, pipe making through welding bi-metal composite plates and site welding, were solved and composite plates have been successfully produced.

At present, the tasks of welding, installation and anticorrosion treatment of this test section have been successfully fulfilled in accordance with the schedule and has met the water supply & drainage requirements.