CN104568232A

CN104568232A - Method for detecting longitudinal residual stress of bar

Info

Publication number: CN104568232A
Application number: CN201410827070.4A
Authority: CN
Inventors: 李国�
Original assignee: Baotou Iron and Steel Group Co Ltd
Current assignee: Baotou Iron and Steel Group Co Ltd; Inner Mongolia Baotou Steel Union Co Ltd
Priority date: 2014-12-26
Filing date: 2014-12-26
Publication date: 2015-04-29

Abstract

The invention relates to a method for detecting longitudinal residual stress of a bar. The method is characterized by comprising steps as follows: a 500 mm long bar section is cut from one end of a to-be-detected bar and taken as a detecting part, a first strain gauge is attached to the position, 250 mm away from the end part, of the detecting part, a second strain gauge is attached to the position where an angle of 180 degrees is formed by the second strain gauge and the first strain gauge in the circumferential direction, accordingly, two strain gauges are attached, the length directions of the two strain gauges are consistent with the length direction of the detecting part, an initial value is measured, and zero clearing is performed; 15 mm long distances are measured from the center of the bar body of the detecting part to two sides, a 30 mm long sample is cut down in the circumferential direction, the final value of longitudinal residual stress is measured, and the average value of residual stress of two testing points is calculated and taken as a residual stress value of the detecting part. The method has the advantages of simplicity and capability of rapidly and accurately detecting longitudinal residual stress of the bar.

Description

A kind of bar longitudinal residual stress detection method

Technical field

The present invention relates to a kind of bar longitudinal residual stress detection method, belong to detection technique field.

Background technology

Bar is one of major product of Baogang, and be the necessity of the engineerings such as building, bridge, the unrelieved stress existed in cold-drawn bar is very high, very easily ruptures, and affects the quality of product, has direct relation with people's productive life.

Because bar residual stress test does not have standard, do not detect the report of bar with strain gauge method, the selection of patch location seems particularly important, and how to detect is the problem studied at present.

Summary of the invention

The object of the invention is, in order to fast, accurately bar longitudinal residual stress can be detected, to provide a kind of bar longitudinal residual stress detection method.

Technical scheme of the present invention is as follows:

The bar section of long 500mm is intercepted as detection piece from bar one end to be detected, a slice first foil gauge is pasted in the distance 250mm position, end of detection piece, circumferentially become with the first foil gauge on the position of 180 degree again and paste a slice second foil gauge, amount to and paste two panels foil gauge, the length direction of two panels foil gauge is all consistent with detection piece length direction, measure initial value, reset; In the centre of detection piece rod body, respectively measure 15mm to both sides, along the circumferential direction cut the sample that length is 30mm, measure longitudinal residual stress final value, calculate the residual-stress value of unrelieved stress mean value as detection piece of two test points.

Advantage of the present invention is: method is simple, can detect the longitudinal residual stress of bar fast and accurately.

Accompanying drawing explanation

Fig. 1 is patch location of the present invention and cutting position schematic diagram.

Embodiment

With reference to accompanying drawing, the bar section of long 500mm is intercepted as detection piece 1 from bar one end to be detected, a slice first foil gauge 2 is pasted in the distance 250mm position, end of detection piece, circumferentially become with the first foil gauge on the position of 180 degree again and paste a slice second foil gauge 3, amount to and paste two panels foil gauge, the length direction of two panels foil gauge is all consistent with detection piece length direction, measures initial value, resets; In the centre of detection piece rod body, respectively measure 15mm to both sides, along the circumferential direction cut the sample that length is 30mm, measure longitudinal residual stress final value, calculate the residual-stress value of unrelieved stress mean value as detection piece of two test points.

The detection of bar meridional stress, is very helpful to the use of bar, such as when bar do bolt use time, its tension can not be too large, otherwise affect workpiece serviceable life.

Claims

1. a bar longitudinal residual stress detection method, it is characterized in that: intercept the bar section of long 500mm from bar one end to be detected as detection piece, a slice first foil gauge is pasted in the distance 250mm position, end of detection piece, circumferentially become with the first foil gauge on the position of 180 degree again and paste a slice second foil gauge, amount to and paste two panels foil gauge, the length direction of two panels foil gauge is all consistent with detection piece length direction, measures initial value, resets; In the centre of detection piece rod body, respectively measure 15mm to both sides, along the circumferential direction cut the sample that length is 30mm, measure longitudinal residual stress final value, calculate the residual-stress value of unrelieved stress mean value as detection piece of two test points.