Three-dimensional measurement method for tensile thickness reduction rate of metal materials

Abstract

The invention discloses a three-dimensional measurement method for tensile thickness reduction rate of metal materials. The method comprising the following steps of: 1) measuring an initial width W and an initial thickness h of the tensile sample of plate materials; 2) carrying out a tensile test; 3) splicing the left and right broken samples of the sample together after the end of the tensile test, and taking a horizontal centerline as a reference and drawing two left and right horizontal cutting marks on the left and right broken samples which are offset from the horizontal centerline by W length; 4) cutting sample along the horizontal cutting marks on the left and right broken samples, and taking the neck region of the sample; 5) cutting the left and right cut samples into 6 pieces in the longitudinal direction; 6) mounting; 8) measuring the thickness reduction rate of each cut sample through a numerical reading microscope on the left cut sample; and 9) calculating the post-breakingreduction rate and the instability reduction rate of the test materials. The measurement result of the invention is scientific and reliable, and has greater significance for the production guidance.

Description

technical field [0001] The invention relates to a testing technology for the mechanical properties of metal materials, in particular to a three-dimensional measuring method for the tensile thickness reduction rate of metal materials. Background technique [0002] In the current standards related to tensile testing, neither the national standard GB / T 228.1-2010 nor foreign standards stipulate the test item or index of thinning rate. In fact, the thinning rate is very important not only for the forming and processing of thin-walled pipes and thin plates, but also for the fracture failure analysis of thick-walled pipes and thick plates. In theory, it can be used as the design control basis in the material manufacturing process and the criterion for structural failure analysis. In theory, it can also be used as a criterion for predicting the forming limit and fracture of materials. [0003] In addition, in the field of metal sheet strip forming processing, there is a parameter ...

AI Technical Summary

Problems solved by technology

These two methods are manual measurement methods. Method 1 has a complicated sample preparation process and low test efficiency; Method 2 has a simple test process and convenient operation, but there are too many manual measurement points, and the later data processing is also cumbersome, and manual measurement errors are relatively large. , affecting the test accuracy

[0005] In general, there is a problem with the above two methods, they only test the thickness reduction rate on the center line of the sample, assuming that the thickness reduction rate of the sample along the width direction is consistent

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