金属材料 - 线材 - 反复弯曲试验

6.5 弯曲时速度要均匀，不能有停顿，不能第二次重复同样的弯曲。必要时放慢弯曲的速度，这样杜绝弯曲时产生的热量影响试验结果。

6.6 为了试验中保持测试线材和圆柱支撑面间的连接，我们可以增加一些负荷。除非有产品标准中另有不同的规定，这个负荷应该等同于在规定拉力的耐力值2%或以下的拉力值。

6.7 重复相同的弯曲试验直到达到产品标准中规定的次数或者直到出现可见的裂缝，禁止使用蛮力。

我们也可以根据产品标准的相关说明试验直至测试件缆完全断裂。

6.8 在反复弯曲试验过程中测试线材出现问题的测试次数不能计入弯曲次数N_b中。

7 试验报告

试验报告应该包括如下内容：

a) 参考本国际标准；

b) 明确测试线材（材料的型号，浇铸序号等等）；

c) 测试线材的公称直径d和最小宽度a；

d) 测试线材准备的详细说明（再次调直方式等）；

e) 试验条件（例如：圆柱表面的半径r，使用的拉力）；

f) 试验结束时的标准；

g) 试验结果。

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SOMMAIRE

TABLE DES MATIÈRES

:current

Foreword

This document (EN 10216-3:2002) has been prepared by Technical Committee EC/TC 29, "Steel tubes and fittings for steel tubes", the secretariat of which is held by UNI.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 2002, and conflicting national standards shall be withdrawn at the latest by November 2002.

This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association, and supports essential requirements of EU Directive(s).

For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document.

Other Parts of EN 10216 are:

Another European Standard series covering tubes for pressure purposes is:

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.

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ISO 657-1 : 1988 (E)

Table 1 — Dimensions and sectional properties of hot-rolled equal-leg angles (concluded)

NOTES

1. Member countries may choose, to be included in their national standards, the sizes which are required to meet their demand.
2. For the angles so chosen, only thicknesses which can be rolled in their mills to meet the demand of the users may be selected from the list of thicknesses corresponding to equal angles in table 1.
3. The sectional area has been calculated using the formula

   S = [l/2 A - l) + 0,214 6 (r_root² - 2r_toe²)] × 1/100

   where
   

   S is the sectional area, in square centimetres;
   

   l is the thickness, in millimetres;
   

   r_root is the root radius, in millimetres;
   

   r_toe is the toe radius, in millimetres;
   

   A is the leg length, in millimetres.

4. Mass is calculated on the basis of density of steel of 7,85 kg/dm³.

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