Quenching temperature of seamless black steel pipe

Posted by zora li on December 19th, 2022

Seamless black steel pipe is uncoated steel, also known as black steel. The dark color comes from iron oxides that form on its surface during the manufacturing process. When the steel pipe is forged, black scales develop on its surface, giving it the same finish as this type of steel pipe.

The specified temperature of the black steel seamless pipe in the quenching process is relatively high, and the specified temperature is close to hundreds or thousands of degrees. Under high temperature and high pressure, the characteristics and advantages of black steel seamless pipe can be more critically developed and brought into play. In use, it can withstand high temperature and high pressure, and is widely used in many engineering buildings. However, the specified temperature during the quenching process of black steel seamless pipe should not be too high. Quenching at too high a temperature can cause various damages. In most cases, black steel seamless pipes will have cracks. Therefore, the quenching temperature of black steel seamless pipe should not be too high.

The overheating of the microstructure after quenching can be observed from the rough edge of the black steel seamless pipe. To accurately distinguish its overtemperature 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 overtemperature structure. If the quenching heating temperature is too high or the heating and holding time is too long, it will lead to the overall overheating of the black steel seamless pipe; it may also be due to the severe banded cementite in the initial structure and the low carbon content in the middle of the two bands. The green zone produces local austenite fiber thickening, resulting in local overheating. The residual martensite in the super-temperature structure of the black steel seamless pipe increases, and the specification reliability decreases. Due to the high temperature of the quenching structure and the coarse 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; overheating is more serious. Quenching cracks.

In the case of quenching, pay attention 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 able to play. Easy to play well.