Straightening Method of Titanium Bar Titanium Wire and Titanium Tube

The common straightening methods of Titanium bar Titanium Wire and titanium tube are: tension straightening, sine straightening, pressure straightening, etc.

Tension straightening, also known as drawing straightening, is a processing method to correct shape defects by applying longitudinal tension to the workpiece that exceeds the yield limit of the material and making it produce plastic extension. When straightening, the tensile stress exceeding the yield limit of the material is applied to the front and back of the titanium rod, titanium wire and titanium tube with wavy shape defects on the tension straightener. The tensile stress is superimposed with the original residual stress of the titanium bar. In the large extension area, part of the tensile stress is offset, which reduces the actual deformation stress and reduces the plastic extension during straightening. In the original small extension, due to the superposition of the tensile stress, the actual deformation stress increases, and the plastic extension increases when straightening. As a result, after the action of tension, all parts of the straightened workpiece extend evenly, and the wavy defects are eliminated.

Straightening

Sinusoidal straightening method is widely used in the production of rod, wire and pipe with simple section. Titanium tube and titanium rod are carried out on the inclined roller straightener. The number of rolls of the straightener is greater than 4(usually 5~29 rolls). Its working principle is to reduce the variation range of the residual curvature of the workpiece gradually through the continuous and repeated three-point bending of each roll.

Sinusoidal straightening is usually used in conjunction with pressure straightening. First, the workpiece with large bending degree is straightened by the pressure straightening machine, and then the inclined roll straightening. The straightening effect mainly depends on the straightening machine pressure and roll Angle. The pressure depends on the yield strength and bending degree of the alloy. If it is a high strength titanium alloy, when the bending degree is larger, the straightening pressure should be larger, and vice versa. Roll Angle depends on the size of the workpiece diameter, the diameter of the workpiece should be larger than the small straightening Angle. After straightening, the unqualified workpiece should be returned to straighten again. It is impossible to straighten the titanium tube should be sent to tension straightening machine straightening.

The basic principles of roller straightening are as follows:

(1) Generally, the smaller the roll diameter and the more rolls, the higher the straightening accuracy; Small roll distance is conducive to the establishment of workpiece biting and straightening process.

(2) The main function of the first few rolls in roller straightening is to reduce the difference of the residual curvature of the workpiece along the length direction, and the main function of the last few rolls is to reduce the residual curvature that tends to be uniform.

(3) The quality of straightening mainly depends on the reasonable determination of the workpiece under the roller reverse bending rate. In the first few rolls (the second, the third roll) to choose a large reverse bending rate, the subsequent roll on the reverse bending rate is determined by the maximum residual curvature just can completely straighten the adjacent roll in front of the maximum.

(4) hardening coefficient 7 is the larger the material straightening more difficult, at this time to choose a larger reverse bending rate and more straightening roll number and smaller roll diameter.