When using A572 gr.50 steel plate, low-alloy high-strength steel, it is desirable to take advantage of its high strength and use a thinner section, not only for saving weight but also for the economy as much as possible. However, the corrosion factor must be fully considered. The thinner the steel section, the more attention should be paid to corrosion protection. Some low-alloy high-strength steels have good atmospheric corrosion resistance, which can not only improve the effect of anti-corrosion coatings, but in some cases, take appropriate precautions and can even be used without being coated in the atmosphere.
The main function of boron in A572 gr.50 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.
According to the data released by the Japan iron and Steel Union (JISF), the export volume of Japanese steel in the second quarter of 2020 A572 gr.50 steel plate is about 4.959 million tons, a year-on-year decrease of 14.2%; the export volume in the first half of 2020 is about 11.07 million tons, with a year-on-year growth of 1.8%. It has been revealed that the year-on-year increase in export volume does not mean that Japan's export A572 gr.50 steel plate situation of Pugang is better in the first half of the year, but only because the base number of the same period last year is too low.