CN2252333Y - Sample for detecting anti-cracking property - Google Patents

Abstract

The utility model belongs to the field of property detection of the metal material. The sample has the composition that a detected material is processed into a rectangular strip shape and is provided with a welding groove. The interior of the welding groove is welded with brittle solder, and the middle section a welding seam is provided with an initiating crack. When a test adopts the three point bending test under the preset temperature, a crack can be stopped after the crack is initiated to a main body of the material due to the crack of the solder. Thus, the utility model can measure anti-cracking critical load and the anti-cracking temperature. Compared with the prior art, the sample can save the test material more than 90%, and both the test equipment and the test method are simple, convenient and reliable. The test expense can be saved by more than 90%.

Description

Detect the sample of crack arrest characteristic

The utility model belongs to the field of metal material Performance Detection.Be specially adapted to detect the sample of metal material crack arrest characteristic.

Any metal material before use, the deviser will be appreciated that the performance that is used of this kind material, can help engineering technical personnel correctly to use each material like this.The mechanical property test method of general material is easier, and the crack arrest characteristic of metal material detects comparatively difficulty.Crack arrest characteristic is meant that this kind material stops the ability of brittle crack expansion, and one removes and uses crack arrest temperature (CAT) as its deliberated index.Test with detecting the crack arrest sample, generally partly form by two, one is the crack initiation part, and two is shank.Crack initiation partly is used for atarting material generation brittle crack, and second partly is the shank that bears drawing stress, is used for test material crack arrest ability to this brittle crack expansion under the effect of different stretch stress level.When temperature is lower than a certain ultimate temperature, under quite low drawing stress effect, the expansion of brittle crack in main body will take place.This ultimate temperature promptly is called crack arrest temperature (CAT).In the prior art, the crack arrest test method that detects metal material has three kinds, and 1 is the Ribertason test, and 2 is SOD or ESSO test, and 3 are double tension test.These three kinds of test methods are the stretching detection method, require detected sample shape, size bigger, and crack initiation is an integral body with shank partly.It is big and single to detect stretcher.Therefore adopt above-mentioned drawing process to detect the crack arrest characteristic of metal material, have with outside the deficiency.Because of detected sample size is big, so spillage of material is serious, the loading and unloading of sample temperature control difficulty all difficult and sample is big when the processing of test sample and test.Above-mentioned in addition test method needs two cover loading systems; Causing brittle crack and make shank bear the effect of stretching constraint stress respectively, and the load mode of shank is direct stretching, needs special large-scale experiment device, so experimentation cost expense costliness, detection difficulty is big.

The purpose of this utility model is that proposition is a kind of simple in structure, and can short form test method and sample reduction experimentation cost, that detect the metal material crack arrest characteristic.

According to the purpose of this utility model, the sample of the detection metal material crack arrest characteristic that we proposed is when detecting test, should be according in deviser's range of set temperature, the loading of detected sample being carried out three-point bending detects, when load was added to certain value, the hard brittle material weld seam root of notch on detected sample then caused brittle crack, and embrittlement cracking is rapidly to sample material of main part internal extended, expand to crack arrest after the certain depth value, the load p when write down crack arrest this moment _zBe critical load.By that analogy, like this with different test temperature values and corresponding critical load P _zAll fasten record at rectangular coordinate, so just can obtain critical load the obviously temperature of turnover takes place, this temperature is a crack arrest temperature (CAT).It more than is the basic functional principle of the utility model test samples crack arrest characteristic.

According to above-mentioned principle, the concrete structure of the detection metal material crack arrest characteristic sample that the utility model proposed can be narrated with reference to the accompanying drawings, and accompanying drawing 1 is for detecting the structural representation of crack arrest characteristic sample, and accompanying drawing 2 is the local enlarged diagrams at the D position of accompanying drawing 1.Load---displacement coordinate curve synoptic diagram when accompanying drawing 3 is surveyed the crooked loading of crack arrest characteristic sample for structure.Accompanying drawing 4 is sample crack arrest temperature (CAT) T _kThe coordinate curve synoptic diagram.A is the sample length overall in the accompanying drawings, and B is the sample beam overall, and C is the sample height overall, and D is analysing and observe of sample weld seam, and a is the weld groove width, and b is a weld groove length, and e is the weld groove height, and d is for causing the crack, and t is for causing the penetration of fracture, and P is a load, and M is displacement, P _zBe crack arrest load, knick point till the K, T are temperature, T _kBe crack arrest temperature (CAT).The composition that the utility model detects the crack arrest characteristic sample is with detected metal material processing rectangularity strip, and the size AXBXC of sample can be according to deciding according to the detectability of the existing three point bending test machine of our unit.Be provided with a weld groove in the stage casing of this sample, in weld groove, be welded with brittle solder, have one in stage casing, brittle solder upper end along the long b direction of weld groove and cause crack d, and perpendicular to sample baseplane direction, weld groove length b should equate with specimen width B, weld groove height e should be less than sample overall height 1/4C, be e＜C/4, weld groove width a should be less than weld groove height e, and the width that causes crack d should be less than or equal to 1/10 initiation penetration of fracture t, be d≤t/10, cause penetration of fracture t and should equal 2/3 weld groove height e.

The preparation of the utility model sample and detection, be that tested metal material processing is become the setting size and has weld groove, then brittle solder is welded in weld groove (the cylinder iron welding rod welding of this sample), again sample welding face is processed smooth back in a/2 weld groove width, open the initiation crack d of an equal length along weld groove length b direction, cause the weld groove height e that penetration of fracture t equals 2/3, cause the width d=t/11 in crack, weld groove width a=4/5e.Then manufactured sample is put on the three point bending test machine and detects, last two fulcrums are respectively in weld seam both sides same distance and parallel support with weld seam, and lower fulcrum is initiation d vertical line opposite, crack, and parallels the direction support with the initiation crack.Accompanying drawing 3,4, be that this sample carries out the record coordinate synoptic diagram that three point bending test loads following of design temperature, the testing result of the utility model sample and the testing result of prior art are close and believable, and test method and test materials are economical.

The utility model sample is compared with the prior art sample and is had following characteristics, adopt the utility model sample to save material more than 90% than the used sample of prior art, and sample processing is simple, test loading and unloading sample is convenient, temperature control easily during detection, the loading equipemtn system can be kept to a cover by former need two covers, therefore can no longer need special test unit, have again because of changing former load test mode, so experiment is not equipped with tonnage obviously to be reduced, experiment can be carried out on general common experimental machine, adopt the utility model sample, just take charge of with regard to testing expenses and save more than 90%.

Claims (2)

1, a kind of sample that detects the metal material crack arrest characteristic, the composition that it is characterized in that this sample is in a rectangle strip sample stage casing one weld groove to be arranged, in weld groove, be welded with brittle solder, have one to cause crack (d) and in stage casing, brittle solder upper end along weld groove length (b) direction perpendicular to sample baseplane direction, weld groove length (b) should equate with specimen width (B), weld groove height (e) is less than sample overall height (c), weld groove width (a) is less than weld groove height (e), cause crack (d) width less than causing penetration of fracture t, cause penetration of fracture t and equal 2/3 weld groove height (e).

2, according to the described sample of claim 1, the every geomery that it is characterized in that above-mentioned detection crack arrest characteristic sample require be:

(1) $e<\frac{c}{4}$ (2) $d\&le;\frac{t}{10}$ (3) $t=\frac{2e}{3}$

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