Method for smelting hydrogen crack resisting container steel with yield level being 245 MPa

Abstract

The invention belongs to the technical field of steelmaking, and relates to a method for smelting hydrogen crack resisting container steel with the yield level being 245 MPa. The method comprises the steps that desulfuration pretreatment is carried out through magnesium injection and lime adding of molten iron, the magnesium injection amount is 0.25 kg / t-0.5 kg / t of steel, the lime adding amount is 3 kg / t-7 kg / t of steel, and the slagging-off time ranges from 7 min to 10 min; converter smelting is carried out, the tapping temperature ranges from 1,570 DEG C to 1,600 DEG C, and the phosphorus content during tapping ranges from 0.003 wt% to 0.005 wt%; LF refining is carried out, and the final sulfur content ranges from 0.0006 wt% to 0.001 wt%; RH vacuum treatment is carried out, and the hydrogen content is smaller than 1.5 ppm at the end; and the slab continuous casting process is completed. The method has the beneficial effects that cost is low, implementation is easy, process control is stable, and popularization is easy.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, in particular to a method for smelting a yield 245MPa grade hydrogen-induced crack-resistant container steel. Background technique [0002] In the field of petrochemical industry, some problems occurred in recent years due to H 2 There are equipment damage or rupture accidents in S, which makes people for H 2 The requirements for the hydrogen-induced cracking resistance (HIC for short) performance of container steel under S corrosive environment are put forward. [0003] Studies have shown that the origin points of hydrogen-induced cracks are all MnS inclusions. At the same time, most of the cracks appear in the core, and some of them appear under the hydrogen bubbles on the surface. In other positions, almost no hydrogen-induced cracks are found. It can be seen that the hydrogen-induced cracks in the core are initiated at the special MnS+ defect interface formed by the MnS inclusions and t...

AI Technical Summary

Problems solved by technology

[0013] The purpose of the present invention is to provide a smelting method for a 245MPa-yield hydrogen-induced crack-resistant container steel, which solves the problem that the defects in the center of the slab caused by the traditional production method greatly increase the occurrence probability of the MnS+ defect interface, so that the hydrogen-resistant cracking produced by the slab is Crack-inducing container steel is prone to hydrogen-induced cracking defects