Low welding crack sensitivity, quenching and tempering, high rigid plate and manufacturing method thereof

Abstract

The invention pertaining to the field of low-alloy steel fabrication technique provides low welding crack sensibility quenching and tempering high-strength steel plates and a method for producing the same. The steel plate comprises the following chemical components by quality percent: C of 0.07-0.09%, Si of 0.20-0.40%, Mn of 1.20-1.40%, Alt of 0.30-0.50%, Mo of 0.10-0.20%, V of 0.04-0.06%, Ti of 0.01-0.02%, and Fe and ineluctable foreign matters of the rest; the tissue are secondary troostite and tempering sorbite.Comparing with the two-stage or three-stage rolling, the rolling adopting a austenite perfect recrystallization section has advantages of omitting a temperature-holding stage for assuring the consistency of rolling steel plates and greatly shortening the rolling time of steel blocks on the basis of simplified processes; rolling only in high-temperature regions, therefore, reducing the requirement of the ability of rolling mill equipment and simultaneously shortening the on-rolling time of the steel plates in a high temperature; room-temperature tissue obtained after rolling providing an appropriate tissue base for obtaining homogeneous tissue after quenching and tempering the steel plates.

Description

technical field [0001] The invention belongs to the technical field of low-alloy steel manufacturing, in particular to a quenched and tempered high-strength steel plate with low welding crack sensitivity and a manufacturing method thereof. Background technique [0002] At present, high-strength steel plates for pressure vessels with low welding crack susceptibility at home and abroad are all delivered in a quenched and tempered state. Domestically, the steel plates delivered in the quenched and tempered state generally use the fully recrystallized austenite and non-recrystallized austenite areas for rolling during the rolling stage. For off-line quenching and tempering heat treatment, under the condition that the composition remains basically unchanged, the microstructure before quenching and tempering has a certain degree of influence on the final microstructure and properties and its uniformity, but the key parameters that determine the final microstructure and properties ...

AI Technical Summary

Problems solved by technology

Using the existing two-stage or even three-stage rolling process, it is inevitable to experience a long waiting time during the rolling process, which prolongs the rolling time of the high-temperature stage of the steel plate. Even if multiple pieces of steel are used for rolling, the rolling mill The effective utilization rate is not high, and its complicated labor also brings great pressure to the operators