Design of smelting composition and smelting process of SN400A, SN400B, SN400C steel, A514 Gr P quenched and tempered steel product: The smelting process adopts low-sulfur molten iron and low-sulfur scrap on the basis of the general process flow of steel for export, adding the refining process of LIIF furnace deep desulfurization and SiCa treatment. In this way, the sulfur content in the steel can be reduced, and the sulfide in the steel can be modified. Greatly improve the toughness of steel and improve the casting performance of molten steel, and increase the qualification rate of the tundish temperature to ensure smooth casting.
The Brazil steel is facing a "crisis of demand" as the epidemic of new crown pneumonia spreads in Brazil. The demand for A514 Gr P quenched and tempered steel and so on steel will be reduced by 50% in April. The demand for the second quarter will be 40% lower than that in the first quarter. The demand for this year will be reduced by 20% compared with the same period this year. In 2019, Brazil's apparent steel consumption was 20.6 million tons, a year-on-year decrease of 2.7%; crude steel production dropped to 32.33 million tons, the lowest since 2016 (30.2 million tons).
2000 tons hot rolled sheet A514 Gr P quenched and tempered steel inventory list7*2920*8780, 6*1650*10570, 5.5*3000*5000, 6*2310*8500, 6*2750*9600, 7*2000*8950, 5*2570*8000, 6*1850*7510, 7*2560*8600, 8*2100*8000, 6*1750*8500, 7*2920*13000, 7*2920*8780, 8*2920*6300, 6*2960*10700, 6.5*2200*10000, 8*1800*6850, 8*3040*4000, 8*1500*4850, 8*1700*6300, 10*2000*7700, 10*2030*8200, 10*1750*6000.
Tempering the important A514 Gr P quenched and tempered steel welding structure often use high temperature tempering to remove residual weld stress. Classification: high temperature tempering above 400 ℃, medium temperature tempering 250 ~ 400 ℃, low temperature tempering 150 ~ 250 ℃, Quenching +Tempering is improve A514 Gr P quenched and tempered steel strength, plasticity and toughness.
