High-strength normalized container steel with yield strength at 415 MPa level and thermal treatment method thereof

Abstract

The invention provides high-strength normalized container steel with the yield strength at the 415 MPa level and a thermal treatment method of the high-strength normalized container steel with the yield strength at the 415 MPa level and belongs to the technical field of steel for pressure containers. When the thickness of the high-strength normalized container steel with the yield strength at the 415 MPa level is 6-29 mm, the high-strength normalized container steel with the yield strength at the 415 MPa level comprises, by weight, not larger than 0.2% of C, 0.1%-0.5% of Si, 1.0%-1.3% of Mn, not larger than 0.035% of P, not larger than 0.035% of S, 0.1%-0.18% of V, 0.4%-0.7% of Ni and the balance Fe and inevitable impurities; when the thickness of the high-strength normalized container steel with the yield strength at the 415 MPa level is 30-55 mm, the high-strength normalized container steel with the yield strength at the 415 MPa level comprises, by weight, not larger than 0.2% of C, 0.1%-0.5% of Si, 1.31%-1.6% of Mn, not larger than 0.035% of P, not larger than 0.035% of S, 0.1%-0.18% of V, 0.4%-0.7% of Ni and the balance Fe and inevitable impurities; and when the thickness of the high-strength normalized container steel with the yield strength at the 415 MPa level is 56-75 mm, the high-strength normalized container steel with the yield strength at the 415 MPa level comprises, by weight, not larger than 0.2% of C, 0.1%-0.5% of Si, 1.61%-1.7% of Mn, not larger than 0.035% of P, not larger than 0.035% of S, 0.1%-0.18% of V, 0.4%-0.7% of Ni and the balance Fe and inevitable impurities. The high-strength normalized container steel with the yield strength at the 415 MPa level and the thermal treatment method of the high-strength normalized container steel with the yield strength at the 415 MPa level have the advantages that the mechanical properties of a steel plate can all meet standard requirements, it can be guaranteed that the steel plate has good tenacity, the technology cost is low, and the technology is easy to implement.

Description

technical field [0001] The invention belongs to the technical field of steel for pressure vessels, and in particular relates to a high-strength normalizing vessel steel with a yield strength of 415 MPa and a heat treatment method. Background technique [0002] The high-strength normalized container steel with a yield strength of 415MPa implements American Standard A 225 / A 225M-12, and its chemical composition percentage is: C≤0.2%; Si: 0.1%~0.5%; Mn≤1.7%; P≤0.035%; S ≤0.035%; V: 0.1%~0.18%; Ni: 0.4%~0.7%; the balance is Fe and unavoidable impurities. [0003] The delivery state of this type of steel is normalized or normalized and tempered. [0004] Its strength level requirements, when the thickness is ≤75mm, all adopt the same standard, that is, the yield strength is ≥415MPa, and the tensile strength is 550MPa~725MPa. [0005] Due to the thickness effect, as the thickness increases, the tensile properties of the steel plate will gradually decrease, but the thickness effe...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a high-strength normalizing container steel with a yield strength of 415MPa and a heat treatment method, which solves the problem that the performance of thick-gauge steel plates and thin-gauge steel plates may exceed the standard