16mn seamless steel pipe cold treatment to prevent cracking

The production and processing of 16mn seamless steel tubes are subject to a series of processing, in the process of processing often used cold treatment, but cold treatment technology is better, but it also has many drawbacks, the more common is the emergence of cracks, which seriously affect the normal use of the effect. For 16mn seamless steel pipe cold treatment how to avoid cracks? We still and 16mn seamless steel pipe manufacturer’s editorial to understand in detail the common preventive measures it:.

16mn seamless steel pipe

　　Preventive measures.

　　(1) 16mn seamless steel pipe after quenching cold treatment before placing 16mn seamless steel pipe in boiling water for 30-60min, can eliminate 15%-25% quenching internal stress and stabilize the residual austenite, and then -60 degrees Celsius conventional cold treatment, or -120 degrees Celsius deep cold treatment, the lower the temperature, the more residual austenite transformed into martensite, the more But it is not possible to complete all the transformation, experiments show that about 2%-5% residual austenite retained, as needed to retain a small amount of residual austenite can relax the stress, its buffering effect, because the residual austenite and soft and tough, can partially absorb the martensitic rapid expansion energy, and moderate the phase change stress;

　　16mn seamless steel pipe is mostly medium and high carbon alloy steel, after quenching there is still part of the subcooling austenite has not turned into martensite, retained in the use of state become residual austenite, affecting the use of performance. If placed below zero degrees to continue cooling, can prompt the residual austenite martensite transformation, therefore, the essence of cold treatment is quenching continues. Room temperature quenching stress and zero degrees under the quenching stress superimposed, when the superimposed back stress exceeds the strength limit of the material will form a cold treatment cracks.