Soft magnetic structure steel possessing good low temperature toughness and easy welding preformance and its manufacturing method

Abstract

An easily weldable soft-magnetic structure steel with better low-temp toughness contains C (0.01-0.02 wt.%), Si (1-2), Mn (0.6-1.0), P (0-0.015), S (0-0.008), Al (0.001-0.01), Cr (0-0.6), Cu (0.2-0.6), Ti (0.005-0.02), Ni (0-1.0), Mg (0.001-0.008), [0] (0.001-0.008), N (0.001-0.006), Ca or REM (0-0.005) and Fe (rest). Its advantages are high strength, low-temp (-30- -40 deg.C) impact toughness, weldability, resistivity and magnetic flux density, better resistance to magnetic ageing and atmosphere corrosion, and low cost.

Description

technical field [0001] The invention relates to a soft magnetic structural steel and a manufacturing method thereof, in particular to a soft magnetic structural steel plate for manufacturing a track beam of a maglev train and a manufacturing method thereof. Background technique [0002] The maglev express train system is a fast, safe, efficient and environment-friendly means of transportation. At present, the fastest maglev train in the world has reached a speed of over 560 km / h. As a fast, safe, efficient, and environmentally friendly means of transportation, it is increasingly favored by people. [0003] Magnetic levitation side-guided soft magnetic structural steel plate is the key component of the maglev guide rail. It can not only absorb the bearing capacity, guiding force and driving force in the maglev track, but also has high magnetic flux density, high resistivity, and good aging resistance. Sex, anti-magnetic timeliness and good weldability, so it has become a hig...

AI Technical Summary

Problems solved by technology

[0005] Due to the significantly high content of C, Als, and Cr, and the significantly low Mn content, the actual impact toughness of soft magnetic steel is low, the resistivity is low, and the strength is low, especially at low temperatures below 0°C (especially below -20°C) The impact toughness is very low, and the transverse impact energy at 0°C is between 12J and 57J; the magnetic induction is not high, B40 is only about 1.60T, and the magnetic induction is low under low magnetic field, B3 is only 0.60T, the electromagnetic conversion efficiency is low, and the ineffective loss is large , cannot adapt to the increasingly stringent environmental protection requirements; and the weldability is relatively poor, so it cannot be used in cold or relatively cold areas

[0006] Chinese patent application No. 01126937.5 discloses that the physical performance of the side-guided soft magnetic structural steel plate of the maglev train track beam produced by this patent is greatly improved compared with the physical performance of the aforementioned German patent technology, but its magnetic flux density, resistivity and low temperature impact Toughness is still not high enough, B40 is about 1.60T~1.61T, B3 is about 0.9T~1.00T, resistivity ρ is about 0.39~0.40μΩm, 0℃Akv≥140J, impact toughness is below -10℃, Akv≥27J cannot be guaranteed, The welding line energy can only be controlled at ≤12kJ / cm to ensure the heat-affected zone (HAZ) 0℃Akv≥27J

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