Composition characteristics of Q420 alloy steel plate: 1.Low carbon: Due to the high requirements for toughness, weldability and cold forming performance, its carbon content does not exceed 0.20%. 2. Add manganese-based alloy elements. 3. Add auxiliary elements such as niobium, titanium or vanadium, which is beneficial to obtain fine ferrite grains and improve the strength and toughness of the Q420 alloy steel, SA572 Grade 65 asme alloy steel plate.
Hydrogen (H) is the most harmful element in general steel such as SA572 Grade 65 asme alloy steel plate. Hydrogen dissolved in steel will cause hydrogen embrittlement, white spots and other defects. Hydrogen, like oxygen and nitrogen, has very little solubility in solid steel. It dissolves into liquid steel at high temperature, and accumulates in the structure without time to escape when cooling, forming high-pressure micro pores, which greatly reduce the plasticity, toughness and fatigue strength of steel, and even cause cracks and brittle fracture in severe cases. "Hydrogen embrittlement" mainly occurs in martensitic steel, but not very prominent in ferrite steel, and generally increases with hardness and carbon content.
Welded steel pipes are made by crimping steel plates, bending them into a circle, and then welding the joints together. Seamless steel pipe is directly processed by round steel piercing or hot rolling process, so there is no weld on the outer surface. The performance of seamless steel pipe is better than that of welded steel pipe, and the price of seamless steel pipe is also higher. There are some differences in chemical composition between SA572 Grade 65 asme alloy steel plate, welded steel pipe and seamless steel pipe. The material of welded steel pipe contains the chemical composition suitable for welding.
According to a report released by South Korea's Pohang Iron and Steel (POSCO), its stainless steel production reached 1.799 million tons in 2020, which was lower than the 1.97 million tons in the previous year and 2.033 million tons in 2018. In terms of quarters, production increased quarter by quarter after the first quarter, and reached the highest level of the year at 502,000 tons in the fourth quarter (an increase of approximately 18.1% from the previous quarter).