News

Why should the quenching temperature of black steel seamless pipes not be too high?

Black steel seamless pipe is uncoated steel, also known as black steel. The dark color comes from iron oxide that forms on its surface during the manufacturing process. When a steel pipe is forged, a black scale forms on its surface, giving it the finish seen on this type of pipe.

The specified temperature in the quenching process of black steel seamless pipe is relatively high, and the specified temperature is nearly 100 degrees and thousands of degrees. Under high temperature and high pressure, the characteristics and advantages of black steel seamless pipe can be more critically developed and displayed. It can resist high temperature and high pressure in use, and is generally used in many engineering buildings. However, the temperature specified in the quenching process of black steel seamless pipe should not be too high. Quenching at an excessively high temperature will cause various damages. In most cases, cracks will occur in the black steel seamless pipe. Therefore, black steel has no The quenching temperature of the seam tube should not be too high.



The over-temperature condition of the microscopic structure after quenching can be observed from the unsmooth edge of the black steel seamless tube. To accurately distinguish its over-temperature level, the structure in the microscope should be carefully checked; if coarse fibrous austenite appears in the quenched structure of GCrl5 steel, it is a quenched over-temperature structure. Too high quenching and heating temperature or too long heating and thermal insulation time will lead to all-round over-temperature of black steel seamless pipe; it may also be due to the serious strip cementite in the initial structure, and the low carbon in the middle of the two belts. The green zone produces partial austenite fibrous stout, which leads to partial overtemperature. The residual martensite in the over-temperature structure of the black steel seamless pipe increases, and the specification reliability decreases. Due to the over-temperature of the quenched structure and the thick crystallization of the steel, the core performance of the black steel seamless pipe is reduced, the impact resistance is reduced, and the service life of the black steel seamless pipe is also reduced; the over-temperature is more serious. Quenching cracks.

In the case of quenching, attention should be paid to the temperature and maturity of the black steel seamless pipe to ensure that the characteristics and functions of the black steel seamless pipe can be played smoothly, otherwise the characteristics of the black steel seamless pipe will not be easy to play well.

Know more about this product price, catalogue, mill test certificate,  please inquiry to: sales@nan-steel.com

Contact