RU2683569C1 - Dressing method of rod shape steel part - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to the field of heat treating, in particular to the field of dressing a part by heating it without the use of physical impact on the part. Dressing of a part using proposed method due to the short duration of heating allows you to save the mechanical properties of the parts obtained during heat treatment. In the method of dressing steel parts of bar form, which includes heating of convex side of the part and cooling in air, in contrast to the known heating of a convex side, the parts are produced by heating surfaces, moreover, the width of each heating surface should be no more than the height of the part at the point of curvature, heating is performed to the temperature ofpoint, heating rate at a given temperature should be such that the heating of a concave half of the part is minimal.EFFECT: technical result of the invention is to improve the quality of manufacturing the part, reduce defect on the inconsistency of the shape of the part and absence of destruction of the part during its dressing.1 cl, 2 ex

Description

The invention relates to the field of heat treatment, and in particular to the field of editing a part by heating it without using mechanical action on the part.

There is a known method of dressing products after heat treatment, in which the product is heated by gas burners to a temperature not exceeding 500 ° C ("Heat treatment in mechanical engineering: Handbook / Ed. By Yu. M. Lakhtin, A. G. Rakhstadt. - M.: Mechanical engineering , 1980. - 783 p., 759 p. ").

The disadvantage of this method is that the heating is carried out over the entire cross section of the part in the place of curvature, as a result of which the mechanical properties, for example, hardness, change, which requires an additional heat treatment operation after dressing.

The closest is the method of editing steel parts of the rod shape, including heating the convex side of the part, and cooling in air (RF Patent No. 2297897 from 12/27/2004, publ. 06/20/2006, IPC B21D 3/02).

The disadvantage of this method is that the heating temperature in this method does not determine the maximum ductility of steel, which reduces the effect of straightening the curvature, as well as the fact that only large-diameter pipes can be edited in this way, since the pipe wall is heated through at two points.

The technical result, to which the invention is directed, is to improve the quality of manufacturing parts, reducing defects by the mismatch of the shape of the part and the absence of destruction of the part when editing. Editing a part by the proposed method in view of the short duration of heating allows preserving the mechanical properties of the part obtained by heat treatment.

, скорость нагрева при заданной температуре должна быть такой, чтобы нагрев вогнутой половины детали был минимальным.The technical result is achieved by the fact that in the method of straightening steel parts of a rod shape, which includes heating the convex side of the part and cooling in air, in contrast to the known heating of the convex side of the part, produce heating surfaces, the width of each heating surface being no more than the height of the part in place curvature, heating to a point temperature

, the heating rate at a given temperature should be such that the heating of the concave half of the part is minimal.

The method is as follows.

. При этом нагревают выпуклую сторону детали последовательно одной или несколькими поверхностями нагрева. Ширина каждой поверхности нагрева должна быть не более высоты детали в месте искривления.A part having curvature is heated, for example by high frequency currents (HDTV), to a point temperature

. In this case, the convex side of the part is heated in series with one or more heating surfaces. The width of each heating surface should not be more than the height of the part at the curvature.

The limitation of the width of the heating surface is necessary so that the heating of the concave half of the part is minimal, in order to ensure the maximum effect of dressing.

The heating rate to a predetermined temperature should be such that the heating of the concave half of the part is minimal. This is necessary in order to ensure the maximum temperature difference between the convex and concave parts of the part to achieve the maximum effect of dressing.

представляют собой температуры аномально высокой пластичности стали, что позволяет достичь наибольшего эффекта при правке искривленной детали. При нагреве детали за пределами этого интервала температур пластичность стали сильно снижается, и, как следствие, снижается или совсем пропадает эффект правки.Point temperature

represent the temperature of anomalously high ductility of steel, which allows to achieve the greatest effect when editing a curved part. When a part is heated beyond this temperature range, the ductility of the steel is greatly reduced, and, as a result, the dressing effect decreases or completely disappears.

The convex side of the part can be heated by one or more heating surfaces, and the place of the next heating should have a temperature close to ambient temperature.

The proposed method allows you to quickly edit the rod parts without resorting to mechanical stress on the part, as well as reduce the time of the operation of editing.

Examples of the method.

Example 1

The proposed straightening method was broached from steel EP863 with dimensions of 340X57X21 mm with a hardness of 66HRC. The broach had a warpage of 0.4 mm with a bulge on the sole. Correction of curvature was carried out as follows: the sole of the broach was heated to a temperature of 740 ... 800 ° C (to a cherry-red color of red-hot) successively in three places. The width of the heating surface is 52 ± 5 mm, the distance between the surfaces is 60-70 mm. The heating time of each surface is 16 seconds. Then the broach was cooled in air. Warpage decreased to 0.2 mm.

Example 2

A bar with a diameter of ∅28 mm made of steel grade 20X in the delivery state with a length of 400 mm has a warpage of 0.6 mm To straighten the bar, the convex side was heated in two places to a temperature of 670 ... 750 ° C (to a dark red color of heat) on both sides of the middle of the bar with a heating surface width of 25-28 mm, the distance between the heating surfaces is 80 mm. The heating time of each surface is 15 seconds. Then the bar was cooled in air. Warpage decreased to 0.35 mm.

Claims (1)

A method for straightening steel parts of a rod shape, including heating the convex side of the part and cooling in air, characterized in that the convex side of the part is heated by heating surfaces, the width of each heating surface being no more than the height of the part at the curvature, heating to a point temperature

, the heating rate at a given temperature should be such that the heating of the concave half of the part is minimal.