Detection method for strain hardening index n value of metal material

A technology of strain hardening index and metal materials, applied in the direction of testing the hardness of materials, etc., can solve the problems of not being widely used, poor fitting accuracy, cumbersome and other problems, and achieve the effect of reducing the detection workload and high precision

Active Publication Date: 2016-01-20
PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0014] In summary, the existing methods are either cumbersome and inconvenient to use directly, or have poor fitting accuracy and cannot be widely used, reflecting the difficulty of finding a simple formula for the n value of materials
Moreover, the relationship between the material n value and the yield strength ratio given by the predecessors has ignored the influence of factors such as composition, structure, and grain size of different steel types on the elastic modulus and initial yield strain of the material. Trying to use an empirical formula to cover all steel types, resulting in a large difference between the predicted results of the n value and the measured results

Method used

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  • Detection method for strain hardening index n value of metal material
  • Detection method for strain hardening index n value of metal material
  • Detection method for strain hardening index n value of metal material

Examples

Experimental program
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Effect test

Embodiment 1

[0120] Calculation of strain hardening exponent n value of a DC06 cold-rolled steel plate

[0121] Taking a DC06 material with a thickness of 0.8mm as an example, its laboratory measurement results are shown in Table 1, and the relevant data in Table 1 are substituted into The C value of the DC06 material is solved as follows:

[0122] C=0.246×140÷302≈0.114

[0123] Then the corresponding relationship between the n value of the DC06 material and the yield strength and tensile strength is:

[0124] The yield strength, tensile strength and n 标 Value is standard value, with the n calculated by the above formula obtained by the present invention 测 For comparison, see Table 4 below:

[0125] Table 4 A certain DC06 material n 标 value and n 测 value comparison

[0126] σs / MPa

[0127] 123

[0128]It can be seen from Table 4 that the maximum relative error between the calculated n value of DC06 material and the standard value is -7.4%, the relative error i...

Embodiment 2

[0130] Calculation of strain hardening exponent n value of a DX54D galvanized sheet material

[0131] The measurement results of the mechanical property parameters of a 0.6mm thick DX54D material are shown in Table 3:

[0132] Substitute the relevant data in Table 3 into Solve the C value of the DX54D material:

[0133] C=0.2324×166÷295≈0.13

[0134] Then the corresponding relationship between the n value of the DX54D material and the yield strength ratio is:

[0135] The yield strength, tensile strength and n The marked value is the standard value, and the n calculated by the above formula obtained by the present invention 测 For comparison, see Table 5 below:

[0136] Table 5 A certain DX54D material n 标 value and n 测 value comparison

[0137] σs / MPa

[0138] It can be seen from Table 5 that the maximum relative error between the calculated n value of DX54D material and the standard value is 7.15%, the relative error is less than 5% in most cases, and the...

Embodiment 3

[0140] Calculation of strain hardening exponent n value of a st13 cold rolled steel plate

[0141] Taking a st13 material with a thickness of 0.5mm as an example, its laboratory measurement results are shown in Table 2.

[0142] Substitute the relevant data in Table 2 into The C value of the st13 material is solved as follows:

[0143] C=0.26×134÷294≈0.1185

[0144] Then the corresponding relationship between the n value of the st13 material and the yield strength and tensile strength is:

[0145] The yield strength, tensile strength and n 标 Value is standard value, with the n calculated by the above formula obtained by the present invention 测 For comparison, see Table 6 below:

[0146] Table 6 A st13 material n 标 value and n 测 value comparison

[0147] σs / MPa

[0148] 133

[0149] It can be seen from Table 6 that the maximum relative error between the calculated n value of st13 material and the standard value is 6.46%, the relative error is less...

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Abstract

The invention belongs to the field of metal material performance detection, and particularly relates to a detection method for the strain hardening index n value of a metal material. The detection method includes the following steps that a, the strain hardening index no value, yield strength delta so and tensile strength delta bo of a metal standard part of a kind of steel are measured; b, the strain hardening index no value, yield strength delta so and tensile strength delta bo are substituted into the formula (I) shown in the specifications, so that the C value of the metal material of the kind of steel is obtained; c, the yield strength delta s and tensile strength delta b of the part, to be tested, of the kind of steel are measured; d, the delta s and delta b values measured through the step c are substituted into the formula (II) shown in the specifications, so that the n value of the metal material is obtained through calculation. The new corresponding relation between the n value and the yield ratio of the material is provided, precision is high, and the method is simple, easy to implement, efficient and rapid, can reduce the workload of detection in a steel factory substantially, and has innovation and breakthrough.

Description

technical field [0001] The invention belongs to the field of performance detection of metal materials, and in particular relates to a detection method of the strain hardening exponent n value of metal materials. Background technique [0002] The material strain hardening exponent n value is a very important mechanical parameter directly related to the stamping performance of parts, and it has direct engineering significance. There are quite many and complex factors affecting the n value. In order to simplify the solution formula of the material n value, scholars at home and abroad have done a lot of experimental research on the method of determining the n value for several years. Various methods have been used to measure and calculate the strain hardening index n Some use empirical relations such as the Holloman relation to calculate the n value, and some use the relationship between the strain hardening exponent in the uniform deformation stage of the metal and the ratio of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/40
Inventor 王飞龙周三宝
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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