Discussion on Hot-piercing Process for 2Cr13 Alloy Steel Pipe

Reasons for the inner spiral defect of the 2Cr13 alloy steel pipe as occurring during the hot-piercing process are described here in the essay.The advantages and disadvantages as brought about by increasing the taper of the plug reeling section are analyzed, and the hot-piercing process parameters are optimized.The analysis leads to the conclusion which covers the following aspects.The piercing parameters need to be properly adjusted, i.e., the distance between the first bite position and the secondary one should be controlled as less than 2.2 pitches, and the pre-piercing screwdown rate should be controlled within 6.5%.Once the mill is accidentally stopped, the billet must be promptly withdrawn into the heating area for reheating.Even in case of front-end sticking, the roll space has to be carefully adjusted, taking the method of trimming the plug front-extending amount as the prior adjustment measure.Proper design of the molds/dies will directly determine quality and production efficiency of the follow-up products.The practice of numerous massive productionsof theserial 2Cr13 productsdemonstratesthat thepipesin high-alloy steel ascontaining 14%~16% alloy elementscan be produced by means of the hot-rolling manufacturing process.