A high temperature tensile fixture

Abstract

The invention discloses a high temperature tensile clamp for tubular products, which is mainly used for a tubular product test sample meeting the detection requirements of high temperature tensile properties. GB / T4338-2006. The high temperature clamp comprises: an outer sleeve, an ejector rod and an inner sleeve, wherein the bottom end of the inner sleeve is mounted on one large-diameter end of a connecting hole of the outer sleeve, and is provided with a mounting hole; a group of guide grooves are formed at the circumferential edge of the mounting hole, and an included angle between the bottom of each guide groove and the central axis of the hole is greater than 0 degree; and a group of clamping titles as many as the guide grooves are each provided with a mounting portion and a clamping portion; the mounting portions are mounted in such a manner of being matched with the guide grooves; the slope of the bottom edge of each mounting portion is consistent with that of the bottom edge of the corresponding guide groove; and each clamping portion is provided with a cambered clamping surface in contact with test piece. The high temperature tensile clamp is not only capable of providing a reliable clamping state to guarantee the detection quality of non-proportional extension strength Rp0.2, but also has large clamping range coverage, so that by using one set of clamp, the use of tubular product test samples within a standard diameter range in high temperature tensile tests can be satisfied.

Description

Technical field [0001] The present invention disclosed a stretch fixture, which involves a tested fixture on the test equipment such as testing equipment such as testing pipe samples in high temperature environment under high temperature environments. Background technique [0002] With the widespread application of high -temperature alloy, titanium alloy and other pipelines in the fields of aviation, aerospace, energy, electrical, chemicals, transportation and medicine, study its mechanical properties in high temperature environments is becoming increasingly important. [0003] As we all know, it is extremely difficult to accurately, reliably, and stably measure the high temperature stretching performance of metal pipes, mainly due to the limitation of the metal pipe itself (including the phenomenon of slippery phenomenon at high temperature at high temperature) and the particularity of the high temperature environmentCause.At present, the high temperature stretching fixture pro...

AI Technical Summary

Problems solved by technology

At present, the high-temperature tensile fixtures for ordinary pipes provided by domestic and foreign testing machine factories are generally prone to slipping at high temperatures, resulting in deformation of the elastic straight line section of the tensile curve, and the phenomenon of "false yielding", resulting in the inability to accurately measure the specified non-proportional elongation strength Rp0.2

Metal materials used in aerospace and other fields have strict requirements on their deformation during work, so once the non-proportional extension strength Rp0.2 of the measured pipe is wrong, it will cause unimaginable consequences

[0004]The existing fixture is mainly composed of a mandrel, a sleeve and a number of clamping tiles installed in the sleeve, which are prone to the following defects: (1) clamping Unreliable: During the clamping process, the distribution state of the clamping tiles is uneven, and it is easy to cause two clamping tiles to move closer together, which limits the axial movement of the two clamping tiles as the load increases during the stretching process. movement and radial movement, resulting in static friction 3Ff < F,; the clamping tiles are not in the same plane, and one of them has obviously moved to the tensile direction of the specimen. Just because two of the clamping tiles are close together, they cannot In order to maintain the balance of force, the remaining clamping shoe is still moving, and the amount of movement must be increased to ensure the clamping of the specimen, resulting in the clamping shoe in the sleeve, Finally, there was a phenomenon that the three clamping tiles were not on the same plane; there were obvious strip scratches at the clamping end of the specimen, which was the phenomenon that the specimen was in an unreliable clamping state, and the relative clamping tiles appeared during the test. Slip, the scratches left by the teeth on the clamping tile on the surface of the specimen, indicating that the specimen has slipped in the fixture

(2) The clamping range is small: a set of fixtures can only hold a test piece of one diameter

Images