Controlled cooling method for ultrahigh-strength heat-treatment-free prestressed steel strand wire rod

Abstract

The invention relates to a controlled cooling method for a prestressed steel strand wire rod, in particular to a controlled cooling method for an ultrahigh-strength heat-treatment-free prestressed steel strand wire rod. The wire rod comprises the following chemical components in percentage, by weight, 0.90%-1.05% of [C], 0.80%-1.10% of [Si], 0.30%-0.60% of [Mn], less than or equal to 0.020% of [P], less than or equal to 0.020% of [S], 0.20%-0.40% of [Cr] and less than or equal to 0.20% of [V]; and the cooling process comprises the steps of wire rod spinning, on-line water bath, heat preservation cover and in-cover electric heating, and specifically comprises the steps that (1) the wire rod spinning temperature is controlled to be 880-920 DEG C; (2) the temperature of the wire rod is controlled to be 800-900 DEG C when the wire rod enters an EDC device, the water bath temperature is controlled at 95-100 DEG C, and the water outlet temperature of the wire rod is controlled to be 500-600 DEG C; and (3) after water is discharged, an online heat preservation cover is completely closed, electric heating is conducted in the heat preservation cover, and the electric heating temperature in the heat preservation cover is controlled to range from 300 DEG C to 500 DEG C. The same-circle performance and the structure uniformity are good, the sorbite rate is high, the wire rod strength is high, and pollution to the environment is avoided.

Description

technical field [0001] The invention relates to a cooling control method for prestressed steel strand wire rods, in particular to a cooling control method for ultra-high-strength heat-free prestressed steel strand wire rods. Background technique [0002] Since the 1990s, the prestressed steel strands used in my country's engineering construction field have mainly used SWRH82B wire rods as raw materials to produce 1860-grade steel strands, which are the main materials for roads, railway bridges and large-span building structures. In recent years, with the improvement of the use function, 1860 steel strands can no longer effectively meet the needs of large-span structures, and the strength of steel strands has become a bottleneck problem restricting the development of prestressed concrete structures. The use of ultra-high-strength prestressed steel strands can not only save the amount of steel, but also reduce the thickness of the concrete cover and reduce the weight of the st...

AI Technical Summary

Problems solved by technology

The key control difficulty of this product lies in composition design and microstructure performance control. For large-scale high-carbon steel wire rods, the cooling capacity of the wire rods produced by the ordinary Stilmore air-cooled process is limited, and the difference between lap joints and non-lap joints causes microstructure properties. poor uniformity

Although the use of salt bath technology can achieve relevant indicators, the cost of salt bath is high, the output is low, and it pollutes the environment.

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