Low-temperature angle steel and manufacturing method thereof

Abstract

The invention relates to a low-temperature angle steel and a manufacturing method thereof, and belongs to the field of low-temperature steels. The angle steel has excellent low-temperature toughness at the temperature of above 40 DEG C below zero, the yield strength of the angle steel reaches 350MPa, and the angle steel is suitable to be used as a power transmission iron tower material under the low-temperature conditions of high cold regions. The angle steel comprises the following chemical components in percentage by weight: 0.05 to 0.18 percent of C, 0.5 to 1.7 percent of Mn, 0.01 to 0.55 percent of Si, 0.005 to 0.01 percent of Ga, 0.01 to 0.08 percent of V, 0.02 to 0.08 percent of Nb, 0.001 to 0.005 percent of Ca, 0.005 to 0.05 percent of Ti, 0.01 to 0.06 percent of Als, 0.15 to 0.25 percent of Cu, 0.0005 to 0.002 percent of B, 0 to 0.01 percent of P, 0 to 0.005 percent of S, and the balance of Fe and inevitable impurities. The angle steel has the advantages of simplicity in process, purity, tissue stability, yield strength of more than 350MPa and excellent low-temperature toughness at the temperature of above 40 DEG C below zero; and by adopting the alloying principles of multiple elements and low quantity, the angle steel has high and low-temperature performance and low cost.

Description

technical field [0001] The invention belongs to the field of low-temperature steel, and in particular relates to a hot-rolled angle steel for low-temperature use and a manufacturing method thereof. Background technique [0002] The problem of low-temperature fracture of materials arose in the 1930s and 1940s with the application of large-scale steel structures. In the 1930s, the Belgian Hasselt Bridge broke and crashed only 14 months after it was built. The temperature at that time was -20°C. The bridge across the highway near Berlin was partially damaged on January 2, 1938 when the temperature dropped sharply to -10°C, and cracks as long as 3m appeared on the bridge. In the 1950s, a bridge in Quebec, Canada, broke and crashed 27 months after it was opened to traffic, when the temperature was -35°C. On December 27, 1965, the derrick of the "Haibao" marine drilling rig in the North Sea gas field collapsed and sank, and the hourly temperature was 3°C. On January 4, 1984, an ...

AI Technical Summary

Problems solved by technology

Generally, these two methods are often used in actual production to improve the low temperature toughness of steel, but due to the high cost of Ni and Mo, economical production is difficult to achieve

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