CN101706409B - Loading device and loading mode for use in measurement of hydrogen diffusion in stress field - Google Patents

Abstract

The invention relates to a loading device and a loading mode for use in the measurement of hydrogen diffusion in a stress field. In the loading device and the loading mode, a loading frame and a loading strip apply a load 1 and/or an axially loading platform applies a load 2 and a hydrogen permeation double electrolytic cell is adopted at the same time so as to realize the random change of a dynamic field in the direction of hydrogen permeation in a thin film within a certain range, namely the change of the size, direction and gradient of the stress field to change conditions for hydrogen diffusion and simulate the conditions of hydrogen diffusion in an actual material. The loading device and the loading mode are widely used in the measurement of the metal hydrogen flux and hydrogen diffusion coefficient of a specified stress field, so an advanced technical means is provided for testing the hydrogen corrosion, hydrogen permeation and hydrogen brittleness sensibility of steel and titanium alloy and other materials used in petroleum and natural gas drilling and transmission equipment, hydrogenation reactors, oil and gas transmission equipment, marine fixed structures, submerged pipelines and the like.

Description

A kind of charger and load mode that is used for stress field hydrogen propagation measurement

Technical field

The present invention relates to a kind of device that in the film like metal sample, produces the given applied stress field; Adopt a pair of rigid frame and associate member, cooperate hydrogen infiltration double-electrolyzer, can realize changing arbitrarily within the specific limits the mechanics field on the hydrogen infiltration direction in the film; Be stress field size, direction and gradient thereof; Thereby change the condition of hydrogen diffusion, the diffusion conditions of hydrogen in the simulation real material provides advanced person's research means for the research of hydrogen diffusion theory and material hydrogen embrittlement/hydrogen-type corrosion failure mechanism.

Background technology

General adopt " the double-electrolyzer method " of the kinetics of diffusion research of hydrogen in metal material promptly respectively has an electrolytic cell on the two sides of film sample to be measured: one for filling the hydrogen electrolytic cell, and opposite side is the oxidization electrolysis pond.The hydrogen kinetics of diffusion process of passing metallic film that adopts this method to record like hydrogen flux, hydrogen rate of propagation, hydrogen diffusion coefficient etc., can only be carried out in the material of no applied stress.And in the common iron and steel and other metal structure that relate to hydrogen harm such as hydrogen-type corrosion, hydrogen embrittlement, all have very high applied stress, and there is higher gradient in stress field.The hydrogen kinetics of diffusion parameter that conventional no applied stress condition is measured can't truly reflect the motion conditions of hydrogen in material; Thereby hydrogen-type corrosion, hydrogen infiltration and hydrogen embrittlement sensitivity assessment are brought very big error; Cause quantitative engineering calculation result to occur than large deviation, for Safety Design and assessment as a result brings uncertainty.It is thus clear that the hydrogen diffusion that takes place in the practical project structure always links together with certain stress-strain field, and often there is very big stress one strain gradient.Simultaneously owing to inevitably have internal stress in the sample; Can cause great interference to test structure; Make the test structure data disperse; Influence the decision-making of people, the engineering assessment of the theoretical research that relates to hydrogen damage and structure is all had a negative impact about hydrogen diffusion problem in the special metal structure.

Summary of the invention

In view of existing in prior technology the problems referred to above; The present invention is intended to disclose a kind of charger and load mode that is used for stress field hydrogen propagation measurement; Its loading duration can through electrochemical method or additive method measure infiltrate (through) the hydrogen amount of this film, carry out dynamics and thermodynamics mensuration that hydrogen diffusion/hydrogen sees through.

Technical solution of the present invention is achieved in that

A kind of charger that is used for stress field hydrogen propagation measurement is characterized in that, comprising:

Locating rack is the rigid support that is arranged between the hydrogen infiltration double-electrolyzer, and the long axis direction of its upper edge testing sample is provided with chute;

Two groups of loading frames are to be supported by locating rack, are arranged in parallel and can in locating rack, slide along its chute along the long axis direction of testing sample; Every group of loading frame comprises two main frames, separates from the both sides of testing sample along short-axis direction, and testing sample is sandwiched in wherein and vertical with the upper and lower surfaces of testing sample;

Loading window, is that middle vertical plane is offered two and loaded windows with the upper and lower surfaces of testing sample on every group of loading frame, in the center of testing sample long axis direction outwards is divided into, loads window and outer loading window;

Add carrier strip, add carrier strip in comprising, load adding carrier strip and adding carrier strip in the window in promptly inserting in, promptly insert in the outer carrier strip that adds that loads in the window; Add that carrier strip treats that the force side of test sample article contacts with the upper and lower surfaces of testing sample respectively and be antisymmetry and arrange with respect to the upper and lower surfaces of testing sample; The adjustable height that adds carrier strip;

Two axial loading bench; Be arranged in the two ends outside of said locating rack respectively along long axis direction; Testing sample is being applied under the axial force state, said axial loading bench one end is fixedly clamped through the two ends of fastening bolt and testing sample, and other end thread connection is on drawing machine.

Said axial loading bench comprises collet body, clamping plate and fastening bolt; Testing sample is being applied under the axial force state; The testing sample end is sandwiched between said collet body and the clamping plate, and is fixedly clamped through fastening bolt, and said collet body is through the screw portion and the drawing machine thread connection of its end.

Antisymmetry described here arranges and is meant, when the testing sample thickness direction examine or check, is the X axle as if thickness direction, and length direction is the Y axle, then at l ₂In the length range, stress is Sigma (x), and is irrelevant with Y, and at X=x place arbitrarily, have Sigma (x)=-(x), promptly at centerline same position place up and down, the stress sign of Y direction is opposite, absolute value equal for 1*Sigma.

In the described charger that is used for stress field hydrogen propagation measurement,

The thickness t of testing sample ₀Be 0.05～2mm;

The width B of loading frame is 60～80mm, and its height W is 60～70mm;

The interior width t that loads window ₁Be 1～5mm, its height 2h ₁Be 16～30mm;

The outer width t that loads window ₂Be 1～5mm, its height 2h ₂Be 16～40mm;

In add the series height d of carrier strip ₁Be 8-1/2t ₀～15-1/2t ₀

Add the series height d of carrier strip ₂Be 8-1/2t ₀～20-1/2t ₀

The distance that adds inside and outside in the same loading frame between the force side of carrier strip promptly loads apart from l ₁Be 5t ₀～50t ₀

In two groups of loading frames separately in the distance that adds between the force side of carrier strip be permanent moment of flexure segment length l ₂Be 50～80mm;

The said force side that adds carrier strip is a wedge structure, and the filtration arc radius R of wedge shape tip is 0.1～1mm.

A kind ofly adopt the mode that the hydrogen propagation measurement loads in the above-mentioned charger stress fields, described charger placed between the hydrogen infiltration double-electrolyzer, and on hydrogen film permeation direction, apply certain stress field, comprising:

Load 1 promptly applies antisymmetry linear gradient stress field:

1. loading frame installing and locating: two groups of loading frames are along testing sample long axis direction parallel arrangements; And in locating rack, slide along its chute, according to the size of testing sample, confirm to add in two the distance between the force side of carrier strip;

2. insert and add carrier strip and fixing testing sample: add carrier strip and add carrier strip in the insertion respectively interior loading window and outer the loading in the window; And be antisymmetry with respect to the upper and lower surfaces of testing sample and arrange; The load that produces therefrom is called load 1; Inside and outside add carrier strip the force side contact with the upper and lower surfaces of testing sample respectively, point of application stepless action is in the whole short-axis direction scope of sample to be tested, thereby grips said testing sample from the upper and lower surfaces of testing sample respectively;

3. adjustment adds the height of carrier strip, obtains needed stress gradient;

Load 2 promptly applies even unidirectional tension stress field:

1. utilize said axial loading bench respectively the two ends of testing sample long axis direction to be gripped;

2. with the other end of said axial loading bench respectively with the drawing machine thread connection;

3. apply pulling force according to needed load, the load that produces therefrom is called load 2;

Load 3 promptly applies unidirectional linearity gradient stress field:

While imposed load 1 and the load 2 formed said unidirectional linearity gradient stress fields that promptly produced with joint efforts.

Charger of the present invention and load mode; Stress-strain field and stress-strain gradient that the hydrogen diffusion takes place in the actual engineering structure have been simulated; Guaranteed that test result is more effective, reflected the motion conditions of hydrogen in material more realistically, so that more effectively assess hydrogen-type corrosion, hydrogen infiltration and hydrogen embrittlement susceptibility; Significantly reduce quantitative engineering calculation result's deviation, for Safety Design and assessment provide foundation more accurately.The present invention can be widely used in measure specifying metallic hydrogen flux, hydrogen diffusion coefficient in the stress field, to the ferrous materials of use such as petroleum gas drilling-production equipment, hydrogenation reaction apparatus, oil gas conveying equipment, ocean fixed sturcture, subsea pipeline and titanium alloy etc. carry out hydrogen-type corrosion, hydrogen permeates and the technological means that a kind of advanced person is provided of hydrogen embrittlement sensitivity Detection.

Description of drawings

Fig. 1 is the structural representation of the said charger of embodiment;

Fig. 2 is the right side load maintainer enlarged drawing among Fig. 1;

Fig. 3 is the A portion enlarged drawing among Fig. 2;

Fig. 4 is the loading mode figure of load 1;

Fig. 5 is the loading mode figure of load 2.Among the figure,

1 locating rack

100,200 hydrogen infiltration double-electrolyzer

21,22 loading frames

3, testing sample

Load window 42,42 ' the outer window that loads in 41,41 '

51, add carrier strip 52,52 ' in 51 ' and add carrier strip

6,6 ' axial loading bench

61 collet bodies, 62 clamping plate, 63 fastening bolts

Embodiment

A kind of charger that is used for stress field hydrogen propagation measurement, as shown in Figure 1, comprising:

Locating rack 1 is arranged in the rigid support between the hydrogen infiltration double-electrolyzer 100 and 200, and the long axis direction of its upper edge testing sample is provided with chute;

Two groups of loading frames 21 and 22 are to be supported by locating rack 1, are arranged in parallel and can in locating rack 1, slide along its chute along the long axis direction of testing sample 3; Every group of loading frame comprises two main frames, separates from the both sides of testing sample 3 along short-axis direction, and testing sample 3 is sandwiched in wherein and vertical with the upper and lower surfaces of testing sample 3, as shown in Figure 2;

Load window 41,42,41 ', 42 ', be opened in that the upper and lower surfaces with testing sample 3 is a middle vertical plane on every group of loading frame 21,22, outwards be divided into and outer loading window 42,42 ' along the center of testing sample 3 long axis directions;

Add carrier strip, add carrier strip 51,51 ' in comprising, load adding carrier strip and adding carrier strip 52,52 ' in the window 41,41 ' in promptly inserting in, promptly insert in the outer carrier strip that adds that loads in the window 42,42 '; Add that carrier strip treats that the force side of test sample article 3 contacts with the upper and lower surfaces of testing sample 3 respectively and be antisymmetry and arrange with respect to the upper and lower surfaces of testing sample; The adjustable height that adds carrier strip;

Two axial loading bench like Fig. 1, shown in Figure 2, are arranged in the two ends outside of said locating rack 1 along long axis direction respectively, and testing sample 3 is being applied under the axial force state; Said axial loading bench 6,6 '; As shown in Figure 5; Comprise collet body 61, clamping plate 62 and fastening bolt 63, testing sample 3 applied under the axial force state that testing sample 3 ends are sandwiched between said collet body 7 and the clamping plate 8; And be fixedly clamped through fastening bolt 9, said collet body 7 is through the screw portion and the drawing machine thread connection of its end.

In the described load maintainer that is used for stress field hydrogen propagation measurement, as shown in Figure 2,

The thickness t of testing sample 3 ₀Be 0.05～2mm;

The width B of loading frame 22 is 60～80mm, and its height W is 60～70mm;

The interior width t that loads window 41 ₁ Be 1～5mm, its height 2h ₁Be 16～30mm;

The outer width t that loads window 42 ₂ Be 1～5mm, its height 2h ₂Be 16～40mm;

In add the series height d of carrier strip 51 ₁Be 8-1/2t ₀～15-1/2t ₀

Add the series height d of carrier strip 52 ₂Be 8-1/2t ₀～20-1/2t ₀

The distance that adds inside and outside in the same loading frame between the force side of carrier strip promptly loads apart from l ₁Be 5t ₀～50t ₀

In two groups of loading frames separately in the distance that adds between the force side of carrier strip be permanent moment of flexure segment length l ₂Be 50～80mm;

The said force side that adds carrier strip is wedge structure, and is as shown in Figure 3, and the filtration arc radius R of wedge shape tip is 0.1～1mm.

Adopt said charger, film metal to be measured (size: 0.2mmX20mmX120mm, surperficial machinery is polished to minute surface, 200 ℃ of vacuum annealings for 35CrMo, 860 ℃ of 300 ℃ of tempering of quenching) applied three kinds of load respectively, comprising:

Load 1 promptly applies antisymmetry linear gradient stress field:

1. loading frame installing and locating: two groups of loading frames are along testing sample long axis direction parallel arrangements; And in locating rack, slide along its chute, according to the size of testing sample, confirm to add in two the distance between the force side of carrier strip;

2. insert and add carrier strip and fixing testing sample: add carrier strip and add carrier strip in the insertion respectively interior loading window and outer the loading in the window; And be antisymmetry with respect to the upper and lower surfaces of testing sample and arrange; The load that produces therefrom is called load 1; Inside and outside add carrier strip the force side contact with the upper and lower surfaces of testing sample respectively, point of application stepless action is in the whole short-axis direction scope of sample to be tested, thereby grips said testing sample from the upper and lower surfaces of testing sample respectively;

3. adjustment adds the height of carrier strip, obtains needed stress gradient;

Load 2 applies even unidirectional tension stress field:

1. utilize said axial loading bench respectively the two ends of testing sample long axis direction to be gripped;

2. with the other end of said axial loading bench respectively with the drawing machine thread connection;

3. apply pulling force according to needed load, the load that produces therefrom is called load 2;

Load 3 promptly applies unidirectional linearity gradient stress field:

While imposed load 1 and the load 2 formed said unidirectional linearity gradient stress fields that promptly produced with joint efforts.

According to above-mentioned loading method, in the testing sample of said film like metal, produce certain stress field, as shown in table 1; In the table, J and D represent diffusion flux and coefficient of diffusion respectively.T in the bracket representes temperature.The test of promptly in this device, carrying out can be carried out under different temperatures, activates characteristic like the diffusion heat of test under specific stress field condition.Probe temperature depends on material and the encapsulating method that electrolytic cell is used.The temperature range that general organic glass electrolytic cell can be tested is 0 ℃～60 ℃, and the temperature range that the glass electrolytic cell can be tested is 0～100 ℃.

The example results of table 1. stress field hydrogen diffusion

Relation table (the unit of notes: mm) between table 2. load 1 loading environment and stress level, the stress gradient (Tw)

Wherein, h ₁=10mm, h ₂=15mm, t ₁=4mm, t ₂=4mm, l ₁=20mm, l ₂=80mm, d ₁=20mm; What load 1 produced is pure bending stress, calculates by following formula:

${\mathrm{\&sigma;}}_w=\frac{M_0}{\mathrm{<figure-callout\; id="0"\; label="I\; t"\; filenames="H2009102196805E00023.png"\; state="\{\{state\}\}">I</figure-callout>}}\frac{t_{}}{}\frac{{}_0}{2}$ (formula 1)

Wherein ${\mathrm{<figure-callout\; id="0"\; label="M"\; filenames="H2009102196805E00023.png"\; state="\{\{state\}\}">M</figure-callout>}}_0=\frac{3}{7}\frac{{\mathrm{Id}}_2}{{\mathrm{<figure-callout\; id="1"\; label="l"\; filenames="H2009102196805E00023.png"\; state="\{\{state\}\}">l</figure-callout>}}_1^2}E,I=\frac{{\mathrm{<figure-callout\; id="0"\; label="Wt"\; filenames="H2009102196805E00023.png"\; state="\{\{state\}\}">Wt</figure-callout>}}_0^3}{12}.$ W is the width of sample to be tested.

Stress gradient is confirmed by following formula:

$T_w=\frac{{\mathrm{\&sigma;}}_w}{{2t}_0}$ (formula 2)

The level that applies of load 2 is only relevant with puller system ability and chuck intensity, sample intensity to be tested.

The coupling that applies needs consideration load 1 and load 2 of unidirectional linearity gradient stress field, that is:

-|σ _wmax|+σ ₂＝0

A normal stress of tape test this moment sample is zero, and another side normal stress is 2 σ wmax, realizes unidirectional linearity gradient stress field.

The above; Be merely the preferable embodiment of the present invention; But protection scope of the present invention is not limited thereto; Any technician who is familiar with the present technique field is equal to replacement or change according to technical scheme of the present invention and inventive concept thereof in the technical scope that the present invention discloses, all should be encompassed within protection scope of the present invention.

Claims (4)

1. a charger that is used for stress field hydrogen propagation measurement is characterized in that, comprising:

Locating rack is the rigid support that is arranged between the hydrogen infiltration double-electrolyzer, and the long axis direction of its upper edge testing sample is provided with chute;

Two groups of loading frames are to be supported by locating rack, are arranged in parallel and can in locating rack, slide along its chute along the long axis direction of testing sample; Every group of loading frame comprises two main frames, separates from the both sides of testing sample along short-axis direction, and testing sample is sandwiched in wherein and vertical with the upper and lower surfaces of testing sample;

Load window, be opened on every group of loading frame and be middle vertical plane, in the center of testing sample long axis direction outwards is divided into, load window and outer loading window with the upper and lower surfaces of testing sample;

Add carrier strip, add carrier strip in comprising, load adding carrier strip and adding carrier strip in the window in promptly inserting in, promptly insert in the outer carrier strip that adds that loads in the window; Add that carrier strip treats that the force side of test sample article contacts with the upper and lower surfaces of testing sample respectively and be antisymmetry and arrange with respect to the upper and lower surfaces of testing sample; The adjustable height that adds carrier strip;

Two axial loading bench; Be arranged in the two ends outside of said locating rack respectively along long axis direction; Testing sample is being applied under the axial force state, said axial loading bench one end is fixedly clamped through the two ends of fastening bolt and testing sample, the other end by the chuck thread connection on drawing machine.

2. the charger that is used for stress field hydrogen propagation measurement according to claim 1 is characterized in that:

Said axial loading bench comprises collet body, clamping plate and fastening bolt; Testing sample is being applied under the axial force state; The testing sample end is sandwiched between said collet body and the clamping plate, and is fixedly clamped through fastening bolt, and said collet body is through the screw portion and the drawing machine thread connection of its end.

3. the charger that is used for stress field hydrogen propagation measurement according to claim 1 is characterized in that:

The thickness t of testing sample ₀Be 0.05～2mm;

The width B of loading frame is 60～80mm, and its height W is 60～70mm;

The interior width t that loads window ₁Be 1～5mm, its height 2h ₁Be 16～30mm;

The outer width t that loads window ₂Be 1～5mm, its height 2h ₂Be 16～40mm;

In add the series height d of carrier strip ₁Be 8-1/2t ₀～15-1/2t ₀

Add the series height d of carrier strip ₂Be 8-1/2t ₀～20-1/2t ₀

The distance that adds inside and outside in the same loading frame between the force side of carrier strip promptly loads apart from l ₁Be 5t ₀～50t ₀

In two groups of loading frames separately in the distance that adds between the force side of carrier strip be permanent moment of flexure segment length l ₂Be 50～80mm;

The said force side that adds carrier strip is a wedge structure, and the filtration arc radius R of wedge shape tip is 0.1～1mm.

4. one kind is adopted the mode that the hydrogen propagation measurement loads in the charger stress fields as claimed in claim 1, described charger is placed between the hydrogen infiltration double-electrolyzer, and on hydrogen film permeation direction, apply certain stress field, comprising:

Load 1 promptly applies antisymmetry linear gradient stress field:

1. loading frame installing and locating: two groups of loading frames are along testing sample long axis direction parallel arrangements; And in locating rack, slide along its chute, according to the size of testing sample, confirm to add in two the distance between the force side of carrier strip;

2. insert and add carrier strip and fixing testing sample: add carrier strip and add carrier strip in the insertion respectively interior loading window and outer the loading in the window; And be antisymmetry with respect to the upper and lower surfaces of testing sample and arrange; The load that produces therefrom is called load 1; Inside and outside add carrier strip the force side contact with the upper and lower surfaces of testing sample respectively, point of application stepless action is in the whole short-axis direction scope of sample to be tested, thereby grips said testing sample from the upper and lower surfaces of testing sample respectively;

3. adjustment adds the height of carrier strip, obtains needed stress gradient;

Load 2 promptly applies even unidirectional tension stress field:

1. utilize said axial loading bench respectively the two ends of testing sample long axis direction to be gripped;

2. with the other end of said axial loading bench respectively with the drawing machine thread connection;

3. apply pulling force according to needed load, the load that produces therefrom is called load 2;

Load 3 promptly applies unidirectional linearity gradient stress field:

While imposed load 1 and the load 2 formed said unidirectional linearity gradient stress fields that promptly produced with joint efforts.

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