Quenching Process

With the rapid development of China's petroleum industry, the demand for high grade steel pipe is becoming more and more large, and the high grade steel pipe must be quenched. Therefore, it is very important to study the overall quenching of the steel pipe. The China Institute of heavy machinery developed two processes of "immersion quenching + internal spray + rotation" and "external spray + internal spray + rotation", and developed a related quenching production line, and achieved good results. The two quenching processes have their own characteristics. The external spray type quenching production line is suitable for the quenching of oil well pipe, oil casing and drill pipe, and it is beneficial to the whole quenching of thin-walled steel tubes. The dipping quenching production line is suitable for the overall quenching of high wall tube with relatively large wall thickness, and its products are mainly used in national defense, nuclear power and petroleum. Natural gas and cars and other industries.

1. Quenching and quenching production line

There are some defects in the quenching equipment of thick wall tube used in China at present, such as (1) the thick wall tube is easy to quench, and the straightness and roundness are poor. (2) the steel tube can not be quenched at the same time, so that the martensite content is low and the hardness is not uniform; (3) the operation cost is high, and the safety is poor. In view of the above defects, the Institute independently developed and manufactured the world's first set of quenching and quenching production lines with "immersion quenching + rotating + internal spray" quenching process to quench the steel tube with a thickness of more than 20 mm.

2. "External spray + internal spray + rotation" quenching process.

This process is aimed at steel tube with thin wall thickness. The steel pipe is heated to about 1000 degrees centigrade by the quenching furnace, and is sent from the feed roller to the waiting position. The feeding device raises the steel pipe and turns it over to the slow rotating support wheel of the rotating device. The pressing device installed on the spray rack quickly presses the steel tube, and the rotating device swiftly revolves the steel tube to rotate quickly, located above the steel tube. The outer spray pipe uniformly sprays water on the outer surface of the steel pipe, while the internal spraying device installed at the end of the steel pipe sprays water into the inner wall of the steel tube. The internal and external surface of the steel pipe is uniformly quenched.