A quenching method for large-diameter thick-walled pressure gas cylinders

Abstract

The invention discloses a quenching method of a major-diameter thick-wall pressure gas cylinder. Based on a numerical simulation technique, under the premise that a major-diameter thick-wall pressure gas cylinder can obtain satisfactory tissues and an inner cavity can release pressure completely and according to the temperature change of characteristic nodes of the body of the pressure gas cylinder and distribution of tissues, the invention provides a quenching and cooling method in which intermittent mist spraying is carried out on the inner surface of the gas cylinder and continuous water spraying is carried out on the outer surface of the gas cylinder when the gas cylinder rotates. The gas cylinder rotates to improve the cooling uniformity of the gas cylinder. The inner surface of the gas cylinder is cooled in a mist spraying manner to reduce the temperature difference of the inner and outer surfaces of the cylinder body so as to reduce the quenching stress, improve the hardenability and reduce the deformation of the cylinder body. The mist spraying pause process of the inner surface is beneficial to good pressure release effect of vapor in the inner cavity of the gas cylinder. By means of the method disclosed by the invention, the quenched major-diameter thick-wall pressure gas cylinder can obtain good tissue distribution, small deformation and residual stress, so that the quenching quality is improved.

Description

technical field [0001] The invention relates to a heat treatment method for a pressure gas cylinder, in particular to a quenching method for a large-diameter thick-wall pressure gas cylinder, and belongs to the technical field of heat treatment. Background technique [0002] With the wide application of natural gas, the demand for large-diameter thick-wall pressure gas cylinders for containing and transporting compressed natural gas is increasing year by year. Due to the long-term work of large-diameter thick-walled pressure gas cylinders in the fatigue environment of loading and unloading, they are subjected to large cyclic stress, and the stress and strain are complex, showing a high stress level. The formulation of the quenching process for large-diameter and thick-wall pressure gas cylinders is the most important link in the heat treatment process of pressure gas cylinders, which plays a key role in their final quality and performance. Large-diameter thick-wall pressure...

AI Technical Summary

Problems solved by technology

Large-diameter thick-wall pressure gas cylinders have the characteristics of large mass, long body, large diameter and relatively small mouth size, etc. The heat treatment process is often very complicated

The traditional gas cylinder quenching process is to quench the gas cylinder directly in the tank, the martensitic transformation is low, the cylinder cannot be completely hardened, and the inner and outer surfaces cannot be cooled at the same time, which often leads to uneven hardness distribution and excessive residual stress , The bottle body is prone to large deformation and other problems, so the traditional quenching process in the tank is only suitable for the quenching production of small-diameter pressure cylinders with small volume

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