What Are The Measures To Reduce The High Temperature Temper Brittleness Of Cold Drawn Seamless Steel Pipes?

Measures to reduce the brittleness of cold-drawn seamless steel pipes during high-temperature tempering include: (1) using oil cooling or water rapid cooling after high-temperature tempering to inhibit the segregation of impurity elements at the grain boundaries; (2) using molybdenum-containing precision bright tubes, When the molybdenum content in the steel increases to 0.7%, the tendency of high-temperature temper embrittlement is greatly reduced. When this limit is exceeded, special molybdenum-rich carbides are formed in the 20# precision steel pipe. The molybdenum content in the matrix decreases, and the brittleness of the precision bright pipe is reduced. On the contrary, the tendency of corrosion increases; (3) Reduce the content of impurity elements in the 20# precision steel pipe; (4) For parts that have been working in the high-temperature tempering embrittlement zone for a long time, it is difficult to prevent embrittlement by adding molybdenum alone. Only by reducing the content of impurity elements in the 20# precision steel pipe Impurity element content, improving the purity of precision bright tubes, and supplemented by composite alloying of aluminum and rare earth elements can effectively prevent high-temperature temper brittleness.