标准搜索结果: 'GB/T 228.1-2021英文版'
| 标准号码 | 内文 | 价格(元) | 第2步 | 交付天数[PDF] | 标准名称 | 相关标准 |
| GB/T 228.1-2021 |
英文版
| 4330 |
购买全文
|
现货, 9秒内下载
|
金属材料 拉伸试验 第1部分:室温试验方法
|
GBT 228.1-2021
|
标准编号: GB/T 228.1-2021 (GB/T228.1-2021)
中文名称: 金属材料 拉伸试验 第1部分:室温试验方法
英文名称: Metallic materials -- Tensile testing -- Part 1: Method of test at room temperature
行业: 国家标准 (推荐)
中标分类: H22
国际标准分类: 77.040.10
字数估计: 81,838
发布日期: 2021-12-31
实施日期: 2022-07-01
旧标准 (被替代): GB/T 228.1-2010
采用标准: ISO 6892-1-2019, MOD
起草单位: 钢铁研究总院
归口单位: 全国钢标准化技术委员会
标准依据: 国家标准公告2021年第17号
GB/T 228.1-2021: 金属材料 拉伸试验 第1部分:室温试验方法
GB/T 228.1-2021 英文名称: Metallic materials -- Tensile testing -- Part 1: Method of test at room temperature
中 华 人 民 共 和 国 国 家 标 准
GB/T 228.1—2021代替 GB/T 228.1—2010
金属材料 拉伸试验
第 1 部分：室温试验方法
国家市场监督管理总局
国家标准化管理委员会
发 布
1 范围
本文件规定了金属材料拉伸试验的定义、符号和说明、原理、试样及其尺寸测量、试验设备、试验要求、性能测定、测定结果数值修约和试验报告。
本文件适用于金属材料室温拉伸性能的测定。
注：附录C 给出了计算机控制试验机的补充建议。
2 规范性引用文件
下列文件中的内容通过文中的规范性引用而构成本文件必不可少的条款。其中，注日期的引用文件，
仅该日期对应的版本适用于本文件；不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
3 术语和定义
GB/T 10623界定的以及下列术语和定义适用于本文件。
4 符号和说明
本文件使用的符号和相应的说明见表1。
5 原理
试验系用拉力拉伸试样， 一般拉至断裂，测定第3章定义的一项或多项力学性能。
除非另有规定，试验应在10℃~35℃的室温进行。对于室温不满足上述要求的实验室，实验室应评估此类环境条件下运行的试验机对试验结果和/或校准数据的影响。当试验和校准活动超过10℃~ 35℃的要求时，应记录和报告温度。如果在试验和/或校准过程中存在较大温度梯度，测量不确定度可 能上升以及可能出现超差情况。
对温度要求严格的试验，试验温度应为23℃±5℃。
如果要求测定弹性模量，应按附录D 进行。
6 试样
6.1 形状与尺寸
6.1.1 一般要求
试样的形状与尺寸取决于被试验金属产品的形状与尺寸。
通常从产品、压制坯或铸件切取样坯经机加工制成试样。但具有等横截面的产品(型材、棒材、线材 等)和铸造试样(铸铁和铸造非铁合金)可不经机加工而进行试验。
试样横截面可为圆形、矩形、多边形、环形，特殊情况下可为某些等截面形状。
非比例试样其原始标距(Lo)与原始横截面积(So)无关。
试样的尺寸公差应符合附录E～ 附录 H 的相应规定(见6.2)。
经与客户协商一致，也可使用其他试样，如有关产品标准中规定的其他试样，如 GB/T 9711、 GB/T19830等。
6.1.2 机加工的试样
如试样的夹持端与平行长度的尺寸不相同，它们之间应以过渡弧连接。若在相应的附录(见6.2)中 对过渡半径未作规定时，建议在相关产品标准中规定。
试样夹持端的形状应适合试验机的夹头。试样轴线应与力的作用线重合。
试样平行长度Lc或试样不具有过渡弧时夹头间的自由长度应大于原始标距(Lo)。
6.1.3 不经机加工的试样
如试样为未经机加工的产品的一段长度或试棒，两夹头间的长度应足够，以使原始标距的标记与夹 头有合理的距离(见附录 E～ 附录 H)。
铸造试样应在其夹持端和平行长度之间以过渡弧连接。此弧的过渡半径尺寸可能很重要，建议在 相关产品标准中规定。试样夹持端的形状应适合于试验机的夹头，试样轴线应与力的作用线重合。平行长度(Lo)应大于原始标距(Lo)。
6.2 试样类型
附录 E～ 附录H 中按产品的形状规定了试样的主要类型，见表2。相关产品标准也可规定其他试样类型。
6.3 试样的制备
应按照不同材料的相关产品标准要求截取样坯和制备试样，如钢产品应符合GB/T 2975的要求。
7 原始横截面积的测定
宜在试样平行长度区域以足够的点数测量试样的相关尺寸。
建议测量试样横截面积时，在试样平行长度区域最少三个不同位置进行测量。 原始横截面积(S。)是根据测量的实际尺寸计算横截面积的平均值。
原始横截面积的计算准确度取决于试样类型。附录 E～ 附录 H 给出了不同类型试样原始横截面 积 S。的评估方法，并提供了测量准确度的详细说明。
用于测量原始横截面积的所有测量装置应按照适当的能溯源至国家测量系统的参考标准进行 校准。
8 原始标距和引伸计标距
8.1 原始标距的选择
8.2 原始标距的标记
对于断后伸长率A 的手动测定，原始标距L。 的两端应使用细小的点或线进行标记，但不能使用引起过早断裂的标记。原始标距应以±1%的准确度标记。
对于比例试样，如果原始标距的计算值与其标记值之差小于10%Lo,可将原始标距的计算值按 GB/T8170修约至最接近5mm的倍数。
如平行长度(Lo)比原始标距长许多，例如不经机加工的试样，可以标记一系列套叠的原始标距。有时，可以在试样表面划一条平行于试样纵轴的线，并在此线上标记原始标距。
8.3 引伸计标距的选择
对于测定屈服强度和规定强度性能， Lo宜尽可能覆盖试样平行长度。这将保证引伸计检测到发生在试样上的全部屈服。理想的 Lo应大于0.5Lo但小于约0.9L。最大力时或在最大力之后的性能， 推荐Lo等于Lo或近似等于Lo,但测定断后伸长率时Lo应等于Lo。
9 试验设备的准确度
试验机的测力系统应满足 GB/T 16825.1要求，并按照 JJG139、JJG475或 JJG1063进行校准，并且其准确度应为1级或优于1级。
引伸计的准确度级别应符合 GB/T 12160 的要求并按照JJG 762 进行校准。测定上屈服强度、下 屈服强度、屈服点延伸率、规定塑性延伸强度、规定总延伸强度、规定残余延伸强度，以及规定残余延伸 强度的验证试验，应使用1级或优于1级准确度的引伸计；测定其他具有较大延伸率(延伸大于5%)的 性能，例如抗拉强度、最大力总延伸率、最大力塑性延伸率、断裂总延伸率，以及断后伸长率，可使用2级 或优于2级准确度的引伸计。
计算机控制拉伸试验机应满足 GB/T22066 的要求，附录C 的建议可供参考。
注：合适的拉伸试验机根据试验机力值校准范围和试样尺寸选取。
10 试验要求
10.1 设定试验力零点
在试验加载链装配完成后，试样两端被夹持之前，应设定力测量系统的零点。 一旦设定了力值零 点，在试验期间力值测量系统不应再发生变化。
注：上述方法一方面是为了确保夹持系统的重量在测力时得到补偿，另一方面是为了保证夹持过程中产生的力不 影响力值的测量。
10.2 试样的夹持方法
应使用例如楔形夹具、螺纹夹具、平推夹具、套环夹具等合适的夹具夹持试样。
宜确保夹持的试样受轴向拉力的作用，尽量减小弯曲(例如更多的信息在 ASTME1012 中给出，见 参考文献[14])。这对试验脆性材料或测定规定塑性延伸强度、规定总延伸强度、规定残余延伸强度或 屈服强度时尤为重要。
为了确保试样与夹头对中，可施加不超过规定强度或预期屈服强度的5%相应的预拉力。宜对预 拉力的延伸影响进行修正。
GB/T 228.1-2021
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.040.10
CCS H 22
Replacing GB/T 228.1-2010
Metallic materials - Tensile testing - Part 1.Method of test at
room temperature
(ISO 6892-1.2019, MOD)
ISSUED ON. DECEMBER 31, 2021
IMPLEMENTED ON. JULY 01, 2022
Issued by. State Administration for Market Regulation;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword... 4
Introduction... 7
1 Scope... 8
2 Normative references... 8
3 Terms and definitions... 9
4 Symbols and descriptions... 17
5 Principles... 19
6 Specimens... 19
7 Determination of original cross-sectional area... 21
8 Original gauge length and extensometer gauge length... 22
9 Accuracy of test equipment... 23
10 Test requirements... 23
11 Determination of upper yield strength... 29
12 Determination of lower yield strength... 29
13 Determination of proof strength, plastic extension... 30
14 Determination of proof strength, total extension... 32
15 Verification and determination of permanent set strength... 32
16 Determination of percentage yield point extension... 32
17 Determination of percentage plastic extension at maximum force... 33
18 Determination of percentage total extension at maximum force... 34
19 Determination of percentage total extension at fracture... 34
20 Determination of percentage elongation after fracture... 34
21 Determination of percentage reduction of area... 35
22 Round-off of test result values... 36
23 Test report... 36
24 Measurement uncertainty... 37
Annex A (informative) Structural changes between this document and ISO 6892-1.2019
... 45
Annex B (informative) Technical differences between this document and ISO 6892-
1.2019 and their reasons... 46
Annex C (informative) Recommendations for the use of computer-controlled tensile
testing machines... 49
Annex D (normative) Determination of modulus of elasticity of metallic materials by
uniaxial tensile test... 57
Annex E (normative) Specimen types used for sheets and strips with a thickness of
0.1mm ~ < 3mm... 70
Annex F (normative) Types of test specimens used for wires, bars and profiles less than
4mm in diameter or thickness... 73
Annex G (normative) Types of test specimens to be used for plates and flats of thickness
equal to or greater than 3mm and wires, bars and profiles equal to or greater than 4mm
in diameter or thickness... 75
Annex H (normative) Types of specimens used for tubes... 80
Annex I (informative) Estimation of compensating crossbead separation rate
considering the deformation of testing machine system... 84
Annex J (informative) Determination of proof strength, plastic extension (Rp) by step-
by-step approximation method... 86
Annex K (informative) Examples for determination of permanent set strength (Rr0.2) by
force-unloading method... 88
Annex L (informative) Method for determination of non-necked percentage plastic
elongation (Awn) of long products such as bars, wires and strips... 90
Annex M (informative) Method for determination of percentage elongation after
fracture less than 5%... 91
Annex N (informative) Determination of percentage elongation after fracture by
displacement method... 92
Annex O (informative) Evaluation of measurement uncertainty... 94
Annex P (informative) Precision of tensile test Results from interlaboratory testing
Bibliography... 105
Metallic materials - Tensile testing - Part 1.Method of test at
room temperature
1 Scope
This document specifies the definitions, symbols and descriptions, principles,
specimens and their dimensional measurements, test equipment, test requirements,
performance measurements, numerical rounding of test results, and test reports for
tensile tests of metallic materials.
This document applies to the determination of the tensile properties of metallic
NOTE. Annex C gives additional recommendations for computer-controlled testing machines.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 2975, Steel and steel products - Location and preparation of samples and test
pieces for mechanical testing (GB/T 2975-2018, ISO 377.2017, MOD)
GB/T 8170, Rules of rounding off for numerical values and expression and
judgement of limiting values
2008, ISO 23718.2007, MOD)
GB/T 12160, Metallic materials - Calibration of extensometers systems used in
uniaxial testing (GB/T 12160-2019, ISO 9513.2012, IDT)
GB/T 16825.1, Verification of static uniaxial testing machines - Part 1.
Tension/compression testing machines - Verification and calibration of the force-
measuring system (GB/T 16825.1-2008, ISO 7500-1.2004, IDT)
GB/T 22066, Evaluation for computerized data acquisition systems for used in static
uniaxial testing machines
JJG 139, Verification regulation of Tension, Compression and Universal Testing
If the parallel length (Lc) is much longer than the original gauge length, for example for
unmachined specimens, a series of nested original gauge lengths can be marked.
Sometimes, a line parallel to the longitudinal axis of the specimen can be drawn on the
surface of the specimen. And mark the original gauge length on this line.
8.3 Selection of extensometer gauge length
For determining yield strength and specified strength properties, Le shall cover the
parallel length of the specimen as much as possible. This will ensure that the
extensometer detects all yielding that occurs on the specimen. Ideally Le shall be greater
than 0.5Lo but less than about 0.9Lc. For the performance at or after maximum force, it
equal to Lo when determining the percentage elongation after fracture.
9 Accuracy of test equipment
The force measuring system of the testing machine shall meet the requirements of GB/T
16825.1.Calibrate according to JJG 139, JJG 475 or JJG 1063.Its accuracy shall be
level 1 or better.
The accuracy level of the extensometer shall meet the requirements of GB/T 12160 and
be calibrated according to JJG 762.When determining upper yield strength, lower yield
strength, percentage yield point extension, proof strength, plastic extension, proof
strength, total extension, permanent set strength as well as verification test of permanent
determining other properties with greater percentage extension (extension greater than
5%), such as tensile strength, percentage total extension at maximum force, percentage
plastic extension at maximum force, percentage total extension at fracture as well as
percentage extension after fracture, an extensometer with level 2 or better accuracy
shall be used.
The computer-controlled tensile testing machine shall meet the requirements of GB/T
22066.Recommendations in Annex C are available for reference.
NOTE. The appropriate tensile testing machine is selected according to the calibration range of the
testing machine force value and the size of the specimen.
10.1 Setting of force zero point
After the test loading chain is assembled, before both ends of the specimen are gripped,
the zero point of the force measurement system shall be set. Once the force zero point
has been set, the force measurement system shall not change during the test.
NOTE. The above method is to ensure that the weight of the gripping system is compensated during
force measurement on the one hand, and to ensure that the force generated during the gripping
process does not affect the measurement of the force value.
10.2 Specimen gripping method
It shall use suitable grips such as wedge grips, threaded grips, push grips, collar grips
It shall be ensured that the gripped specimen is subjected to axial tension. Minimize
bending (for example, more information is given in ASTM E1012, see Bibliography
[14]). It is particularly important when testing brittle materials or when determining
proof strength, plastic extension, proof strength, total extension, permanent set strength
or yield strength.
To ensure that the specimen is centered on the grip, a pretension may be applied not
exceeding the specified strength or 5% of the expected yield strength. The extension
effect of pretension shall be corrected.
10.3 Testing rate
Unless otherwise specified, as long as the requirements of this document are met, the
choice of Method A1, Method A2, or Method B, as well as the testing rate, is decided
by the sample provider or its designated laboratory.
NOTE 1.The difference between Method A and Method B is that the testing rate required by
Method A is defined at the point of interest (for example, Rp0.2), and is also the property to be
measured. The testing rate required by Method B is generally set in the elastic range prior to the
measured property.
Under certain conditions of Method B (for example, for some steels with a stress rate
of approximately 30MPa/s in the elastic range, use a high stiffness gripping system and
observed.
NOTE 2.Product standards and related test standards (such as aviation standards) or agreements
may specify testing rates that differ from this document.
10.3.2 Testing rate based on strain rate (Method A)
10.3.2.1 General
Method A is intended to reduce testing rate variation and measurement uncertainty in
test results when determining strain rate sensitive parameters (performance).
This document describes two different types of strain rate control modes.
- Method A1 Closed Loop. The strain rate () is based on feedback from the
- Method A2 Open Loop. The strain rate is estimated from the parallel length.
That is, it is realized by controlling the crossbead separation rate obtained by
multiplying the parallel length by the required strain rate [see formula (2)].
NOTE. A more rigorous strain rate estimation procedure for Method A2 is described in Annex I.
If the material exhibits discontinuous yielding or zigzag yielding (as in some steels and
AlMg alloys at the yield stage or as in the Portevin-LeChatelier zigzag yielding effect
exhibited by some materials) or when necking occurs, the force value can be kept
nominally constant. The strain rate () and the estimated strain rate () based on
the parallel length are approximately equal. If the material exhibits the ability to deform
the compliance of the testing machine system may cause the actual strain rate to be
significantly lower than the set value of the strain rate.
The testing rate shall meet the following requirements.
a) Unless otherwise specified, a stress equivalent to half the expected yield strength
may be achieved at any convenient testing rate. Thereafter until the range of ReH,
Rp or Rt is determined, the specified strain rate (), [or the crossbead separation
rate (vc) estimated from the parallel length in Method A2]. This range requires an
extensometer to be gripped on the specimen to measure the maximum specimen
extension and eliminate the influence of the flexibility of the tensile tester, so as
machines that are not capable of strain rate control.
b) During discontinuous yielding, an estimated value of the parallel length strain rate
() shall be used, see 3.7.2.In this range it is not possible to control the strain
rate with an extensometer gripped to the specimen, because partial plastic
deformation may occur beyond the extensometer gauge length. Use the constant
crossbead separation rate (vc) calculated from formula (2). In this range it is
possible to keep the estimated value of the required parallel length strain rate
sufficiently accurate.
c) After the determination of RP, Rt or the end of yield range (see 3.7.2), it shall use
|