Do you know the application of large-diameter seamless steel pipe induction heating quenching and tempering production line composed of medium frequency induction heating power supply?

Large-diameter seamless steel pipe induction heating quenching and tempering treatment process is generally used to process seamless steel pipes with an outer diameter of 100-510mm and a wall thickness of 5-38mm. These steel pipes are used in high yield strength, high toughness casing, tubing and drilling tools for oil and gas drilling. Since the well depth of oil and gas wells has been extended from the usual 2500-5000m to 5000-7000m, the pressure in the well has increased from 20-40MPa to 40-60MPa. The axial tension and various compressive stresses endured by oil and gas well casing and tubing increase with the increase in well depth, and the requirements for the strength and toughness of casing and tubing increase accordingly. According to API (American Institute of Petroleum Engineers) standards, high requirements are put forward for the mechanical properties of casing and tubing. It is difficult to meet the requirements using traditional thermal technology. The above requirements can be fully achieved by using medium frequency induction heating power supply for induction heating quenching and tempering process.

(1) Brief introduction of foreign applications. In 1975, the United States first built a large-diameter seamless steel pipe induction heating quenching and tempering production line composed of a medium-frequency induction heating power supply, which was used to process seamless steel pipes used in oil and gas drilling. The total heating power of the production line is: 9000kw, 1800Hz for the quenching part; 6000kw, 1000Hz for the tempering part. The production capacity is about 24t.h-1. Subsequently, Japan built its second induction heating quenching and tempering production line in 1977. The total heating power of the production line is: 3500kW, 1000Hz for the quenching part; 3000kW, 1000Hz for the tempering part. The production line can process steel pipes with outer diameters of 114-340mm and wall thicknesses of 15-22mm, with an annual output of 100,000 tons.

After 1980, the United States, Japan, and Russia successively built several large-diameter seamless steel pipe induction heating, quenching and tempering production lines. The total heating power is 5000-8000kw, the power frequency is 1800-2500Hz, and the production capacity is 12-30t.h-1. The materials of quenched and tempered steel pipes include Cr-Mn, Cr-Mo, Cr-Ni-Mo and other medium carbon low alloy steels. The process used in induction heating quenching and tempering treatment is roughly similar, the quenching temperature is 880-960℃, water quenching, and the tempering temperature is 550-750℃ air cooling. The room temperature mechanical properties of the steel pipe after quenching and tempering treatment comply with the relevant provisions of API standards. At present, after induction heating quenching and tempering treatment of the highest grade steel, the room temperature mechanical properties of the steel pipe can reach a yield strength of 1400MPa, a tensile strength of 1600MPa, and an elongation greater than 12%.

(2) Brief introduction of domestic application. Since the 1990s, in order to adapt to the rapid development of oil and gas drilling in my country, the production of oil and gas drilling using steel pipes has been based on the domestic market to meet the needs of the domestic market. Several large-diameter seamless steel pipe induction heating quenching and tempering production lines have been introduced from abroad. These production lines are respectively configured in the steel pipe production plant and the petroleum machinery plant. Over the years, it has made contributions to the production of steel pipes for oil and gas in my country. In 2003, the large-diameter seamless steel pipe induction heating quenching and tempering production line designed and manufactured by Wuxi Zhenwu Electric Furnace Manufacturing Co., Ltd. was completed. The total heating power of the production line is 6800kw, of which the quenching part is 4000kw, 3000Hz and 1000Hz; the tempering part is 2800kw, 2000Hz and 1000Hz, the production capacity is 12t.h-1, and it can process steel pipes with an outer diameter of 50-210mm. According to the domestic manufacturing level of heating power supply and the level of mechanical, electrical and automatic control, it is fully capable of mastering the induction heating quenching and tempering treatment equipment and process production technology of large-diameter seamless steel pipes.

This article briefly introduces the application of the induction heating, quenching and tempering treatment production line for large-diameter seamless steel pipes. I hope it can deepen your understanding of this production line. If you want to know the specific components of this production line, you can consult our technical staff.