Roll forming method of 0Cr19Ni9 stainless steel thin-walled ring forging

Abstract

The invention discloses a roll forming method of a 0Cr19Ni9 stainless steel thin-walled ring forging. In order to roll-form a thin-walled ring forging with high dimensional precision and excellent tissue and performance, the technical scheme comprises the steps of: firstly, sleeving a preheated follower die sleeve and a 0Cr19Ni9 stainless steel pre-rolled blank heated to a deformation temperature in a ring rolling mill, sleeving the follower die sleeve in the pre-rolled blank, and positioning the two workpieces by using a main roll, a core roll, clutching rolls, an upper cone roll and a lower cone roll of the ring rolling mill; and starting the ring rolling mill, making a feeding motion by the core roll towards the direction of the main roll along the radial direction and rolling the pre-rolled blank at a rolling force of 140-2800KN under the support of the follower die sleeve by the core roll together with the main roll to ensure that the pre-rolled blank expands radially at a speed of 7-14mm / s, wherein the wall thickness is gradually reduced, and the pre-rolled blank is rolled into the thin-walled ring forging when the deformation reaches 40-60 percent. The minimum value of the wall thickness of the 0Cr19Ni9 stainless steel thin-walled ring forging roll-formed by adopting the method is 25mm, the maximum value of the height-thickness ratio is 25mm, and the ring forging is mainly used for gyrorotor parts used in the fields, such as oil gas and the like.

Description

technical field [0001] The invention relates to a rolling forming method of a ring forging, in particular to a rolling forming method of a 0Cr19Ni9 stainless steel thin-walled ring. Background technique [0002] 0Cr19Ni9 stainless steel belongs to the austenitic stainless steel with type number 304 in ASTM A473-01 (R09) of the American Society for Testing and Materials. The steel thin-walled ring formed by rolling process requires high tensile properties and corrosion resistance. It is mainly used for rotary parts used in fields such as oil and gas. During rolling, due to the small deformation of the ring, the thinner wall thickness, and the higher requirements for dimensional accuracy, performance and structure, the difficulty of rolling and forming is increased. [0003] Chinese Invention Patent Specification CN 101279343A published on October 8, 2008 discloses a rolling forming method for stainless steel special-shaped ring forgings. In this method, alloy bars blanked ac...

AI Technical Summary

Problems solved by technology

When using this method to roll thin-walled 0Cr19Ni9 stainless steel thin-walled rings, since the rolling die is fixed on the roll (that is, the main roll and the core roll), the gap between the pass of the rolling die and the pre-rolled billet will Intense friction not only makes the rolling process very unstable and affects production, but also easily leads to the temperature rise of the pre-rolled billet, which affects the structure and properties of the steel, such as defects such as structure variation and coarse grains.

[0004] When using the above method and directly using the main roll and core roll of the ring rolling machine to roll (such as the rolling ring billet in the above method) thin-walled 0Cr19Ni9 stainless steel thin-walled rings, due to the rigidity of the core roll and other components of the rolling ring machine In addition to the poor structural rigidity and small machining allowance of the thin-walled ring, it is easy to cause plastic instability of the pre-rolled billet during the rolling process, resulting in flattening, bell mouth, etc., resulting in the shape and size of the ring not reaching It is scrapped due to design use or machining requirements, which will cause a certain loss to the 0Cr19Ni9 stainless steel material that is not cheap

[0005] During the rolling process, when the pre-rolled slab is just rolled, the hand first shifts to the holding roll on one side of its rotation direction, and then to the other side of the holding roll, so that the pre-rolled slab will move toward its rolling process. The left and right swing of the holding rollers on both sides is affected by the reaction force generated by the holding rollers, and the rings are easily crushed and scrapped

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