A detection method for strain-intensified non-uniform deformation of stainless steel welded joints

A detection method, strain strengthening technology, applied in the direction of applying stable tension/pressure to test the strength of materials, etc., can solve the problems of sample destruction, cumbersome handling, and difficulty in realizing the continuity of detection positions, etc., and achieve the effect of reducing accidents

Inactive Publication Date: 2017-05-03
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, due to the complexity of strain-enhanced heterogeneous deformation in the stainless steel welded joint area, the existing computer finite element simulation cannot truly reflect the heterogeneous change of the welded joint under the influence of multiple factors; it is also difficult to realize the detection position by using strain gauges. Continuity; the micro-tensile test can only give the non-uniform deformation properties of a small area selected in any direction, and it is difficult to reflect the non-homogeneous deformation characteristics of the workpiece under the real size, and the preparation process and operation of the micro-sample method are relatively complicated. The requirements for the sample are high, and the follow-up processing is cumbersome, so it is difficult to apply in actual engineering
The fixed-point marking method for deformation detection of cold-rolled steel strip proposed by the Chinese invention patent (201110433604.1) needs to drill through holes at fixed points, which is destructive to the sample; the plasticity of austenitic stainless steel proposed by the Chinese invention patent (201210550221.7) The non-destructive testing method of deformation is the method of DC magnetization, and the actual deformation is obtained by comparing the calibration relationship curve between the deformation and the residual magnetic field strength of austenitic stainless steel before and after plastic deformation. Detection method of non-homogeneous deformation of welded joints

Method used

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  • A detection method for strain-intensified non-uniform deformation of stainless steel welded joints
  • A detection method for strain-intensified non-uniform deformation of stainless steel welded joints
  • A detection method for strain-intensified non-uniform deformation of stainless steel welded joints

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Embodiment 1

[0040] 304 austenitic stainless steel plate with a thickness of 10mm, the size of the test plate is 180mm×160mm×10mm, the test plate is welded by plasma arc welding, and its chemical composition is C 0.06%, Si 0.40%, Mn 1.62%, P 0.026%, S0.012%, Ni 8.14%, Cr 18.03%, Fe balance.

[0041] (1) Preparation before testing

[0042] Use a press to correct and level the deformation of the stainless steel test plate after welding, fix the weldment between the two supports, the back of the weld seam faces upward, and make the weld seam coincide with the centerline of the two supports, and then apply downward pressure on the weldment The pressure makes it produce plastic deformation opposite to the welding deformation, compensates the original welding deformation, and is beneficial to adjust the distribution of residual stress in the test plate and reduce the residual stress.

[0043] In order to prevent the structure and performance from being affected by the excessive temperature duri...

Embodiment 2

[0050] 304L stainless steel plate with a thickness of 12mm, the size of the test plate is 200mm×180mm×12mm, the test plate is welded by plasma arc welding + argon tungsten arc welding, and its chemical composition is C 0.02%, Si 0.50%, Mn 1.60%, P0.024%, S 0.014%, Ni 11.00%, Cr 19.80%, Fe balance.

[0051] (1) Preparation before testing

[0052] Use a press to correct and level the deformation of the stainless steel test plate after welding, fix the weldment between the two supports, the back of the weld seam faces upward, and make the weld seam coincide with the centerline of the two supports, and then apply downward pressure on the weldment The pressure makes it produce plastic deformation opposite to the welding deformation, compensates the original welding deformation, and is beneficial to adjust the distribution of residual stress in the test plate and reduce the residual stress.

[0053] In order to prevent the structure and performance from being affected by the excess...

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Abstract

The invention relates to a method for detecting strain strengthening non-homogeneous deformation of a stainless steel welded joint, which comprises the following steps of carrying out correcting and leveling on the deformation of a welded stainless steel test panel by utilizing a press machine; cutting a leveled weldment along the direction vertical to a welding line by adopting high-pressure water jet; carrying out finish machining on the cut surfaces of all the samples of the weldment, so as to guarantee the width of each sample of the weldment and the surface roughness of two cut surfaces to be set values; carrying out equal-spacing scribing and gauge length delimitation on the samples of the weldment; carrying out strain strengthening on the samples of the weldment along the direction vertical to the welding line; measuring the spacing distance between adjacent lines of the samples of the weldment after tensile strain strengthening; calculating the strain rate of each region of the samples of the weldment, and making a coordinate graph of the strain rates and positions, so as to obtain the tendency of the non-homogeneous deformation of all the regions. The invention provides the method for detecting strain strengthening non-homogeneous deformation of the stainless steel welded joint, and theory and experiment data are provided for the use safety of a strain strengthening stainless steel container.

Description

technical field [0001] The invention belongs to the technical field of welding detection, and in particular relates to a detection method for strain-enhanced heterogeneous deformation of stainless steel welded joints. Background technique [0002] In actual production and life, the problem of material heterogeneity cannot be ignored, especially the weak areas of key components are the focus of most attention. The welded joint is a heterogeneous body composed of weld seam, fusion zone and heat-affected zone. It has different degrees of inhomogeneity in structure and performance. The heterogeneity of welded joints is one of the important issues involved in the weldability of materials. The performance of the weak zone determines the performance of the entire weldment. Therefore, accurate detection of the heterogeneity of welded joints has always been concerned. [0003] Due to its good corrosion resistance and weldability, stainless steel is widely used in construction, brewi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N3/08
Inventor 李亚江刘坤王娟
Owner SHANDONG UNIV
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