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Jiangyin Eternal Heavy Industry Co.,Ltd was established in 2008, it is National high-tech enterprise, innovative small and medium-sized enterprise. Till now our main products including all kinds of special steel forgings and heavy duty hydraulic cylinder. Our special steel forgings include all kinds

Jiangyin Eternal Heavy Industry Co.,Ltd was established in 2008, it is National high-tech enterprise, innovative small and medium-sized enterprise. Till now our main products including all kinds of special steel forgings and heavy duty hydraulic cylinder. Our special steel forgings include all kinds

Jiangyin Eternal Heavy Industry Co.,Ltd was established in 2008, it is National high-tech enterprise, innovative small and medium-sized enterprise. Till now our main products including all kinds of special steel forgings and heavy duty hydraulic cylinder. Our special steel forgings include all kinds

The fracture of the 9Cr2Mo steel cold rolling roll is classified as hydrogen embrittlement fracture, with the crack initiation site located at the circular spots inside the roll where hydrogen accumulates. High hydrogen content and large quenching stress caused by delayed tempering are the main causes of hydrogen embrittlement fracture of the roll, while severe dendrite segregation and abundant inclusions accelerate the fracture. The recommendations are as follows:① Improve metallurgical quality to reduce the content of inclusions and the degree of segregation in the steel;② Increase the forging ratio to avoid dendrite segregation in the material;③ Prolong the hydrogen diffusion time to reduce the hydrogen content of the roll;④ Conduct tempering in a timely manner to reduce the quenching stress of the cold rolling roll.

Forged steel cold rolling rolls commonly use electric slag steel to manufacture roll blanks; Steel ingots are usually treated with high-temperature diffusion to improve the uniformity of the chemical composition of the rolling billet; The roller blank is deformed by forging, and the material has good density; After forging the roll blank, normalizing treatment is carried out to eliminate secondary network carbides, and spheroidization annealing treatment is performed to prepare the microstructure for the subsequent quenching and tempering treatment; Perform hydrogen expansion annealing to prevent the formation of white spots.

The problem of Grade 4 network carbides and a small amount of eutectic carbides in Cr5 forged steel caused by improper post-forging heat treatment design can be solved by optimizing the heat treatment process. High-temperature normalizing is adopted to dissolve most carbides into the matrix, followed by rapid cooling using water-based or oil-based quenching media to ensure full austenite transformation, reduce precipitation of secondary carbides, thereby sufficiently refining the microstructure and avoiding the formation of network carbides. Ultimately, zero defect echoes and favorable bottom echoes are achieved in testing.