Petroleum casing heat treatment to improve toughness

Petroleum casing emerged not only for oil extraction but also as a pipeline for transporting raw materials. In order to strengthen the quality of petroleum casing, every link in the production process is particularly important, especially the temperature control during the period, which must be mastered in strict accordance with the regulations. Usually, the petroleum casing is quenched by sub-temperature quenching method instead of the ordinary quenching method, because the ordinary quenching method adopted will allow a large amount of residual stress inside the workpiece, thus expanding the brittleness, and the subsequent processing is not so convenient. The sub-temperature quenching is to prevent the brittleness of the oil casing from affecting the subsequent process. The main operation method is to first select the heating temperature for sub-temperature quenching, usually between 740-810°C, and the heating time is usually about 15 minutes. After quenching and then tempering, the heating time of tempering is fifty minutes, and the temperature should be selected to 630°C. Of course, each type of steel has its own heating temperature and time during heat treatment, and as long as the performance of the workpiece can be improved and enhanced, then the purpose of heat treatment will be achieved.

Heat treatment is the most important process in the processing of oil casing, the performance and quality of the finished product can meet most of the results of heat treatment, so the manufacturers of heat treatment process requirements are very strict, do not dare to have a trace of slack. Sometimes can also be quenched by means of low-temperature quenching, low-temperature quenching can effectively remove the residual stress of the oil casing, not only to reduce the degree of deformation of the workpiece after quenching, but also to process the oil casing into a more suitable raw material for the later process. Therefore, the current achievements of petroleum casing and heat treatment are inseparable. Since the heat treatment process, regardless of the impact toughness, destruction resistance or tensile strength of petroleum casing, there has been a great improvement.