The main function of boron in A709 Gr HPS70W bridge steel plate and so on steel is to increase the hardenability of steel, so as to save other rare and precious metals, such as nickel, chromium and molybdenum. For this purpose, the boron content is generally regulated in the range of 0.001% - 0.005%. It can replace 1.6% nickel, 0.3% chromium or 0.2% molybdenum. It should be noted that molybdenum can prevent or reduce temper brittleness, while boron slightly promotes temper brittleness, so molybdenum can not be completely replaced by boron.
The main competitive means adopted by major domestic ports are to expand ports, build deep-water berths and channels, improve service quality to reduce the comprehensive cost of customers, and at the same time, to improve competitive advantage, we should also take appropriate measures to reduce relevant costs and prices.
Flat steel is a kind of steel with rectangular cross-section and blunt edges at the edges and corners. It is usually 12-300 mm wide and 3-60 mm thick. Compared with A709 Gr HPS70W bridge steel plate ordinary steel plate, the utilization rate of flat steel is increased by one to five percentage points. Moreover, flat steel can be produced with fixed thickness, width and length according to the user's requirements, which saves the cutting process for users, reduces the consumption of labor and materials, and also reduces the processing loss of raw materials, saving time, labor and material.
The seamless steel pipe for general use is rolled by common carbon structural steel, A709 Gr HPS70W bridge steel plate, low alloy structural steel or alloy structural steel, with the largest output. It is mainly used as the pipe or structural part for conveying fluid. According to different uses, it can be divided into three categories: a according to chemical composition and mechanical properties; B according to mechanical properties; C according to hydrostatic test. If the steel pipe supplied according to class AB is used to accept liquid pressure, hydrostatic test shall also be carried out. The seamless pipes for special purposes include seamless pipes for boiler, chemical power, geological and petroleum, etc.
