Mechanical and Process Properties of Low-alloy Steel Plates for Low-temperature Pressure Containers GB3531-1996
Abstract
This article mainly introduces the mechanical properties of low-alloy steel plates for low-temperature pressure containers GB3531-1996. According to the experimental results, it can be seen that It is mainly used to produce low-temperature pressure vessels in the fields of liquefied natural gas, liquefied petroleum gas and its media. It has excellent mechanical properties, good process performance and it can be used safely under the specified conditions.
Keywords: Low-alloy steel plate; Mechanical property; Process performance
1. Introduction
Low-temperature pressure vessels are widely used in the low-temperature liquefied gas industry, and the materials used for them also have certain requirements. Low-alloy steel is a commonly used material in the manufacture of low-temperature pressure vessels. Generally speaking, its properties have certain requirements, such as mechanical properties, process performance and so on. GB3531-1996 is a national standard for the mechanical properties of low-alloy steel plates for low-temperature pressure vessels. This standard mainly stipulates the mechanical properties and process performance of low-alloy steel plates for low-temperature pressure vessels.
2. Mechanical Property
GB3531-1996 specifies the mechanical properties and process performance of low- alloy steel plates for low-temperature pressure vessels. The mechanical properties mainly include tensile property, yield strength and elongation. 2.1 Tensile Property. The tensile property of low-alloy steel plates includes the test method, tensile strength, yield strength and elongation, the test method should meet the requirements of GB/T228 Tensile Test Method of Metallic Materials. The tensile strength at room temperature is not less than 380MPa, the yield strength at room temperature is not less than 235MPa, and the elongation is not less than 22%.
2.2 Yield Strength. The yield strength of GB3531-1996 is expressed by the yield ratio, which means that the yield strength is expressed by the ratio of the yield strength to the tensile strength. The yield ratio stipulated in this standard is not less than 0.6. According to the actual test results, the yield ratio of low-alloy steel plates for low-temperature pressure vessels is not less than 0.6.
2.3 Elongation. The elongation at break of the processed low-alloy steel plates for low-temperature pressure vessels is not less than 22%, and the test results of the actual test show that it is not less than 22%.
3. Process Performance
The process performance of low-alloy steel plates for low-temperature pressure vessels is mainly reflected in the hot rolling process performance, cold rolling process performance, heat treatment process performance and welding process performance.
3.1 Hot Rolling Process Performance. The hot rolling process performance of low-alloy steel plates for low-temperature pressure vessels includes surface quality, scale content, thickness uniformity, flatness, edging, size and other indicators. The scale content must not exceed 0.03%, and the variation of the thickness should be controlled within 0.5mm. For the flatness and edging, the deviation values of the two should be controlled within the stipulated range.
3.2. Cold Rolling Process Performance. The cold rolling process performance of the low-alloy steel plates for low-temperature pressure vessels includes surface quality, scale content, shape accuracy and thickness uniformity. The scale content of the cold-rolled low-alloy steel plates for low-temperature pressure vessels must not exceed 0.03%, and the shape accuracy must meet the requirements of GB/T17635.2-1995.
3.3 Heat Treatment Process Performance. Heat treatment process of low-alloy steel plates for low-temperature pressure vessels includes solution treatment, quenching treatment and tempering treatment. The solution treatment temperature must meet the requirements of GB/T16749-1997, and the quenching temperature must meet the requirements of GB/T699-1999.
3.4 Welding Process Performance. The welding process of low-alloy steel plates for low- temperature pressure vessels includes preheating, pressure welding and heat treatment. Preheating must meet the requirements of GB/T 13954-1992, and the pressure welding must meet the requirements of GB/T 11351-1997.
4.Conclusion
GB3531-1996 is a national standard for the mechanical properties and process performance of low-alloy steel plates for low-temperature pressure vessels. According to the experimental results, it can be seen that It is mainly used to produce low-temperature pressure vessels in the fields of liquefied natural gas, liquefied petroleum gas and its media. It has excellent mechanical properties, good process performance and it can be used safely under the specified conditions.
