戴姆勒•克莱斯勒有限公司关于电镀氢脆的预防方法

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HYDROGEN EMBRITTLEMENT RELIEF

氢脆的预防方法

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DAIMLERCHRYSLER CORPORATION
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戴姆勒·克莱斯勒有限公司

Process Standard
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作业标准
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出版日期：2002.01.14

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1
GENERAL 综述

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1.1
" ~6 S- s' b5 L% B  b0 TPurpose of the Standard 适用范围

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This standard outlines the procedures and requirements for preventing hydrogen embrittlement in high-strength steel parts. High strength steel fasteners are covered by this standard but nuts are excluded. Hydrogen embrittlement can be caused by acid cleaning, phosphating or electroplating, because of hydrogen absorption, and lack of relief before tensile stresses are applied to the material. This standard is commensurate with SAE/USCAR-5 with the exception of the hardness value cut offs where a specific procedure such as a holding period or a heat treatment is required. Where these standards differ, the specific requirements in this standard take precedence over SAE/USCAR-5.

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本标准规定了高强度钢制零件的氢脆预防的方法和要求。本标准适用于除螺母以外的高强度紧固件。经过酸洗、磷化或电镀等表面处理的钢制零件，在受到拉伸应力之前如未采取防治措施，将会因吸收氢原子而引起脆断。本标准与SAE/USCAR-5标准原则上基本相同，但决定是否采取放置释放或是否进行烘烤处理方法的硬度值有所不同。本标准与SAE/USCAR-5标准部分内容不一致时，本标准中的规定的要求高于SAE/USCAR-5
标准。

1.2
Purpose of the Process 主题内容

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This standard presents the process for preventing hydrogen embrittlement in high-strength steel.

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本标准介绍了高强度钢制紧固件的氢脆防治的方法。

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2
PROCESS 处理方法

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2.1 Applicable Hardness of Fasteners Requiring Hydrogen Relief 要求进行驱氢处理的紧固件的硬度

The hardness levels referred to in this standard that will determine the type of hydrogen relief required is the “specified case hardness” for case hardened fasteners (MS-4515, MS-5479, and MS-5001). For through hardened and tip hardened fasteners (MS-3517, MS-5766, MS-7483, MS-4515B, MS-6149 and MS-8253), the hardness that shall apply in determining the type of hydrogen relief is the “specified core hardness.”

对于表面硬化型的紧固件(MS-4515、MS-5479及MS-5001)，本标准明确提出，决定其去氢处理方式主要取决于其“表面硬度”。对整体调质或局部淬硬型紧固件(按标准MS-3517、MS-5766、MS-7483、MS-4515B、MS-6149及MS-8253)，决定其去氢处理方式主要取决于其“芯部硬度”。

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2.2 Categories of Surface Treatment 表面处理的类型

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2.2.1 Acid Cleaning 酸洗

Acid cleaning must be minimized on high-strength/high-hardness steel parts because it can contribute to hydrogen embrittlement. Therefore, if fasteners or parts with a specified Rockwell hardness of HRC 32 or greater are to be acid pickled, it is required that a procedure be established for processing the parts that limits the time in the acid to a maximum of 10 minutes. Controls must be implemented and records kept on the type and concentration of the acid used, exposure time, acid bath temperature, and the type and amount of inhibitor. It is required that records be kept on when the parts entered and exited the various processing stations. For automatic plating equipment, a record of the cycle time will suffice until the cycle is changed or until the line is interrupted due to breakdown or otherwise.

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必须尽量减少高强度/高硬度钢制零件的酸洗，因为酸洗可加剧氢脆。因此，洛氏硬度等于或大于HRC 32的紧固件进行酸洗时，必须在制定酸洗工艺时确保零件在酸中浸泡的时间最长不超过10分钟。必须及时并完整地记录和控制酸的种类及浓度、酸洗时间、温度及抑雾剂的类型和数量。并应对零件进出各道工序点时间进行记录。对于电镀自动生产线，若无生产周期变化、生产线故障或其他原因，也应当有生产周期时间的记录。
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( e8 t$ d7 p& Y% J  A* g0 AWhen hydrogen is absorbed by acid cleaning, it will usually dissipate within 48 hours. It is the responsibility of the primary supplier to make sure the parts are not delivered to the plant before this time period has elapsed (see Table 1).
酸洗时吸收的氢通常会在48小时内自行释放。一级供应商有责任确保在此期间的零件不交付给客户（见表1）。

  s0 P/ J* ?# n, ^' ]0 CAs an option, the parts can be placed in a preheated, forced-air-circulating oven for one (1) hour at 115 +/-10 degrees C. See Section 2.3 for details on the baking procedure.
( M' @6 h2 ~! d* i4 [  l另外一个选择，零件可以放置在热风循环炉（去氢炉）中，温度为115±10℃下烘烤1小时。详见2.3条烘烤方法。
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: D3 f5 y/ [8 Y2.2.2 Phosphating (PS-80) 磷化(按PS-80)
% }4 ]6 o+ x4 q; ^+ `; m: sAll parts with a specified hardness of HRC 32 or greater, which are acid cleaned (not to exceed 10 minutes) and phosphated to the requirements of PS-80 shall be held in the supplier’s plant for 48 hours or baked for one (1) hour at 115 +/- 10 degrees C. (See Table 1 and Section 2.3 for Baking Procedure).
; ^0 }0 V( {) o0 @  E4 a7 I7 l* c2 }$ L; G% J所有硬度等于或大于HRC 32的零件，酸洗（不超过10分钟）后再按PS-80标准进行磷化的，应在供应商的工厂内放置48小时，或在115±10℃温度下烘烤1小时（见表1及2.3条烘烤方法）。
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2.2.3 Mechanical Plating (PS-1536, PS-8956M) 机械镀(按标准PS-1536, PS-8956M)
. z/ I0 X$ R& A/ aSome hydrogen is absorbed during the acid cleaning and processing procedure of the mechanical plating process. When steel parts with a specified hardness of HRC 32 or greater are coated by this procedure, they should be held for 48 hours before shipping to the plant. As an option, the parts may be baked for 1 hour at 200 +/- 10 degrees C. (See Table 1 and Section 2.3 for Baking Procedure).
经过酸洗并机械镀的零件会吸收一些氢。经过这样表面处理的零件若硬度大于等于HRC 32，应在交付给客户之前放置48小时。或在200±10℃下烘烤1小时（见表1及2.3条烘烤方法）。

The approved sealer shall be applied after baking.
封闭处理工序应在烘烤工序完成后再进行。

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TABLE 1:: HYDROGEN RELIEF FOR PICKLE AND OIL PHOSPHATE, AND MECHANICALLY

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PLATED HIGH-STRENGTH/HIGH HARDNESS PAPTS （1）

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表1：酸洗及涂油、磷化、机械镀的高强度/高硬度零件（1）的驱氢方法

PROCESS 8 @" o3 Q3 H+ V8 g' K 表面处理种类过程 9 Y( t" b' s* J5 b+ R( b9 `	REFERENCE 9 B% y6 a( i4 f- q 参照标准 4 q! q- b( s8 I- S, I6 \' E" B	HARDNESS HRC 4 T/ {* X5 `9 i, R0 l5 v8 } 硬度HRC 2 F1 F" B% ?2 a0 z 0 n$ l7 z% I9 e. J; B	HYDROGEN RELIEF ; D" I$ m8 X1 n 驱氢方法
Acid Pickle " i7 E5 g+ M  |9 ORust and Scale removal (No finish other than oil is Applied) 5 V4 y- W) l" g+ @8 y) V酸洗(除锈及氧化皮)、涂油（不再进行其他表面处理）	" L& G3 j' L# M; G8 g	32 of greater ≥32	Hold parts for 48hours 放置48小时 7 [3 E! I; i1 `4 J' |, m& v6 m0 U9 kOption:Bake parts for hour at ! L/ [! o1 \- b8 z2 m0 U, [115+/-15 degrees C 或：在115±10℃下烘烤1小时放
Phosphate 磷化	PS-80	32 of greater ≥32 & _* v' I7 c2 M3 J# R( h/ ]1 z	Hold parts for 48hours ( V# N, j* O- ]7 C! W& u放置48小时 Option:Bake parts for hour at 115+/-15 degrees C * z7 X$ T4 y. V8 z* i或：在115±10℃下烘烤1小时 $ H2 E1 f7 T0 K
Mechanical Plate * K% o' O0 M0 C8 z机械镀 ( E6 W. s2 P. I. O. S	PS-1536 5 y9 `% q! i: E: J( SPS-8956M	32 of greater ≥32	Hold parts for 48hours 8 t7 k5 Z9 g9 M! \. A3 g放置48小时 Option:Bake parts for hour at 200+/-15 degrees C 或：在200±15℃下烘烤1小时

(1) The hydrogen embrittlement test is not required for these finishes.

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(1)这些表面处理种类不要求进行氢脆试验。

2.2.4 Zinc Plating (PS-4220), Zinc Alloy Plating (PS-8955), Cadmium Plating (PS-754), Tin Plating of Spring Steel (PS-791), and Tin-Zinc Alloy Plating (PS-8956E)

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% a% |7 B1 N( ~* J8 Z' h! y[ 本帖最后由 rockston 于 2008-12-18 11:39 编辑 ]

j.chen404

表中温度好象有错，文件中及翻译中都是+/－10%，表中的是+/－15%。好资料，收藏了，谢谢！

rockston

镀锌(按标准PS-4220)、镀锌合金(按标准PS-8955)、镀镉(按PS-754)、弹簧钢镀锡(按标准PS-791)及镀锡锌合金(按标准PS-8956E)

High-strength/high hardness steel parts with a Rockwell hardness of HRC 32 or greater, that are to be cadmium or zinc electroplated must be plated to the requirements of PS-754 (cadmium) or PS-4220 (zinc) and MUST BE PROPERLY BAKED WITHIN ONE HOUR after plating, and prior to chromate coating. See Table 2 for bake schedule and Section 2.3 for baking procedure.

洛氏硬度等于或大于HRC 32的高强度/高硬度钢制零件，必须按标准PS-754 (镀镉)或PS-4220 (镀锌)进行镀镉或电镀锌，并且必须在镀后1小时内进行适当的烘烤，且烘烤是在铬酸盐钝化之前进行。烘烤时间见表2和第2.3条烘烤措施。

TABLE 2: HYDROGEN RELIEF SCHEDULE FOR ELECTROPLATED

HIGH-STRENGTH/HIGH HARDNESS PARTS

表2：电镀的高强度/高硬度零件的驱氢方法

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ROCKWELL HARDNESS 洛氏硬度HRC 0 ^; |3 v" T; z5 j) t# C	TEMPERATURE(C) 烘烤温度℃ 3 h7 ~& l! L1 b; W$ Y	BAKE TIME(AFTER PLATING) Embrittlement test required Where indicated by”TEST” 烘烤时间（镀后） 是否要求氢脆试验	MAXIMUM COATING SPECIFICATION 最大镀层厚度
Less than 32 ＜32	-----	Not required 4 i- R. A6 \( v/ @" W. G不要求试验	Code 50 (12 micrometers) 4 r0 B: R( D0 h7 C( X& ^50号（12μm） . V$ B2 @. {, E  [ : e. i& R" m. }; n6 [
32 to 36 32~36	200+/-10 degrees 200±10℃	4 hours minimum bake-TEST " A2 [( u! l3 s7 q至少烘烤4小时-要求试验 ! B: x% i( G& e3 J& h( X	Code 30 (8 micrometers) 30号（8μm）
37 to 39 37~39	200+/-10 degrees 200±10℃	8 hours minimum bake-TEST 至少烘烤8小时-要求试验 - I2 N( P2 m* j) S5 q" x9 a% I	Code 30 (8 micrometers) 30号（8μm）

NOTE: Unless otherwise specified, and excluding tip-hardened fasteners, high-strength steels having a hardness greater than HRC 49 shall not be electroplated. High-strength steels having an HRC 32 or greater shall not be specified to more than Code 30 (8). On all existing drawings where Code 50 is specified for a part with hardness of HRC 32 or greater are hereby understood to be Code 30.

注：除非另有规定，除了局部淬硬型紧固件外，硬度超过HRC 49的高强度钢制零件不允许采用电镀表面处理的形式。硬度等于或大于HRC 32的高强度钢制零件的镀层厚度不能超过30号（8μm）。现有的所有图纸上若要求硬度大于等于HRC 32的零件镀层厚度为50号的，均应按30号进行处理。

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2.3 Baking Parts to Prevent Embrittlement 烘烤零件防止脆性

High-strength/high-hardness steel parts MUST BE PROPERLY BAKED in a well controlled, calibrated, hot-air-recirculating batch oven, or in a continuous conveyor type oven, within one hour after processing. A baking schedule based on hardness is described in Table 2.

高强度/高硬度钢制零件在电镀后1小时内必须采用可控温的校准过的热风循环箱式炉或连续式网带炉进行适当的烘烤。烘烤时间见表2。

The time for the parts to come up to temperature SHALL NOT be counted as part of the minimum bake time. Because the oven air temperature can differ from the temperature of the parts in a batch oven, the temperature of batch baked parts must be monitored with a thermocouple placed in the middle of the load of parts, in the last place in the oven to reach the bake temperature in order to insure that the proper baking time and temperature are reached. For continuous bake ovens, a temperature trace through the oven must be run with a calibrated thermocouple in the lowest temperature position, at least once a year.

因为箱式炉内温度可能会与零件温度有一定的差异，零件在炉内升温的时间不允许计入最短烘烤时间内。必须将热电偶插入到零件堆的中间，此处是炉内最后达到烘烤温度的地方，这种方法可确保零件在正确温度下的烘烤保温时间。对于连续式烘烤炉，必须有温度曲线记录仪，热电偶放置在炉内温度最低的位置，每年至少检测一次炉温。

Methods should be implemented to aid the heat-up rate of the parts. This includes reducing the size of the load placed in the oven, using smaller containers, and using containers fabricated from wire mesh and perforated sheet to allow air circulation into the load. The type of fastener or part, the configuration of the load in the oven, oven identification, and load weight, etc., must be recorded and kept on file for future reference. It is required that records be kept on the bake temperature and when the parts entered and exited the bake oven.

并应采取措施，提高零件在炉内的升温速度。比如：减少炉内装载量、使用较小的容器、用铁丝网和带孔薄板做成容器便于热风流通。紧固件或零件的类型、零件在炉内的排列方式、烘烤炉的鉴定、炉内装载重量等等，必须详细记录。零件进出烘烤炉的时间、还有当时的炉温也都必须有记录可查。

3
HYDROGEN EMBRITTLEMENT TEST 氢脆试验

Hydrogen embrittlement testing must be applied to finished parts prior to shipments. A torque/tension test is used for threaded parts and a tensile test is used for non-threaded parts. The test consists of three steps:

电镀的高强度/高硬度零件在交付客户之前必须进行氢脆试验。螺纹件做扭拉试验，无螺纹件做拉伸试验。试验由以下三个步骤组成：

A. Determine the ultimate torque or tensile stress to failure for threaded and non-threaded parts respectively.

分别确定螺纹件和无螺纹件的极限扭矩或断裂拉伸应力。

B. Load the parts to 80% of the ultimate torque or tensile stress.

在零件上加载极限扭矩或断裂拉伸应力的80%。

C. Maintain the torque or tensile stress for 48 hours. Whenever possible, the test fixture should simulate the intended application.

; _5 H: R. W" h0 L保持扭矩或拉伸应力48小时。只要条件允许，试验夹具应模拟实际服役条件来制作。

It is the sole responsibility of the supplier to insure that the test procedure, fixture and loads are sufficient to detect the presence of hydrogen embrittlement in the finished part prior to shipment.

供应商有责任在成品交付前确保试验方法、夹具和载荷能够准确地检测出氢脆性的存在。

3.1 Test Load Determination 试验载荷的确定

3.1.1 Threaded Parts 螺纹件

Randomly select a minimum of five parts from the lot being evaluated to establish the test load for the stress test. Note that the five-part sample is only to establish the test load used for the hydrogen embrittlement tests. The hydrogen embrittlement test sample size is determined in Section 3.2.

从待测的同一批零件中随机抽取至少5个零件，确定试验载荷。注意此5个样本仅仅用来确定氢脆试验的试验载荷。氢脆试验的样本大小在3.2条中有明确规定。

A.

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A.
' ^5 _; Q7 V' z+ p9 eApply torque to the test part or the mating part of the text fixture until ultimate failure of the test assembly occurs. The assembly must use material of comparable strength levels. Parts of the same configuration must be used throughout the hydrogen embrittlement test. Record the failure torque for each of the five test fasteners. Suggested fixturing methods are discussed in Section 3.6.

对测试零件或相配的工装夹具施加扭矩直至零件最终损坏。夹具配件必须使用强度等级相匹配的材料制作。整个氢脆试验必须始终保持相同的零件装配结构。记录5个试验紧固件的破坏扭矩。推荐的装配方法在3.6条中论述。

The test fixture must represent the intended use of the fastener, and does not have to be application specific. *Hand or power tool tightening is acceptable, however, the selected tightening method must also be used in performing the hydrogen embrittlement test (Section 3.3).

试验夹具应当模拟紧固件的服役条件，但可以不完全相同。试验工具可以采用手动拧紧工具或电动拧紧工具，但氢脆试验中使用的拧紧工具必须与确定试验载荷时使用的工具一致。（3.3条）。

B.
* F: P; h3 u5 {7 l- WThe torque to be used in the hydrogen embrittlement test shall be 80% of the average of the five failure torque readings taken in Step 1. This torque value does not necessarily correspond to the actual application installation torque for the part.

氢脆试验中使用的力矩是第1步中得出的5个破坏扭矩的平均值的80%。试验扭矩值可与零件实际装配时的扭矩值不一定相同。

C.
* K) h1 z7 U; Z9 IFor threaded parts proceed to Section 3.2 Sample Size Determination and Section 3.3 Performing Hydrogen Embrittlement Test.

对于螺纹件，按照第3.2条确定样本大小和按照第3.3条进行氢脆试验的实施。

3.2 Sample Size Determination 样本大小的确定

A lot for the purpose of the hydrogen embrittlement test is defined as follows. For a batch oven, a lot is a load of baked parts with the same part number. For a continuous baking furnace, a lot (for a particular part number) is to be defined by the supplier as is agreeable with their process; keeping in mind that if a failure should occur during the subsequent hydrogen embrittlement test, the lot shall be scrapped. The lot shall be defined such that all processing traceability is maintained for each part number/lot identification. Samples used for the hydrogen embrittlement test must be randomly selected from the lot.

用于氢脆试验的一个零件批次的定义如下。对于箱式炉，一个批次是指尺寸、表面处理、性能等级等技术要求相同，在同一时间内、同一炉内烘烤的相同零件号的零件。对于连续式烘烤炉，一个批次（指相同零件号）是由供应商确定的适合其操作的批次；不过必须注意如果在接下来的氢脆试验中发生了一个零件损坏，则整个批次的零件都应报废。每个零件号或每个批次号必须能追溯到整个生产过程。用作氢脆试验的样品应当从一批零件中随机选取。

The number of parts to be subjected to the hydrogen embrittlement test must be 115 pieces if the lot is 2,300 parts or greater, or 5% of the quantity of the lot if less than 2,300 parts. Parts that are comprised of several components must be tested as whole assemblies.

若整批零件数量达到或超过2300件，则做氢脆试验的样本量必须达到115件，若整批数量少于2300件，则做氢脆试验的样本量应为整批数量的5%。由几个组件构成的总成件必须作为一个整体进行试验。

3.3 Performing Hydrogen Embrittlement Test <S> 氢脆试验的实施

A.
The total number of parts determined in Section 3.2 are to be subjected to the hydrogen embrittlement test.

做氢脆试验的样本量按3.2条来确定。

B.
These parts are to be loaded using the same fixture, the same loading methods and the same test load determined in Section 3.1.1 for threaded parts or Section 3.1.2 for non-threaded parts. Parts which fail while attempting to be assembled to the test torque (load) should be discarded and cannot be counted as part of the test lot.

这些零件用相同的夹具装夹，相同的装夹方式和相同的试验载荷（螺纹件按3.1.1条，无螺纹件按3.1.2条）。装夹时，未达到试验扭矩（载荷）就损坏的零件应废弃，并不能计入被试验批次的样本量中去。

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C.  These parts are to be held at load in the fixture for a period of 48 hours. After the 48 hours have elapsed:
# V2 b; ]" r3 u8 A" N3 T7 R* q这些零件应装夹在夹具中48小时。48小时之后：
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' P* I& G7 g2 c3 y9 n! \- For threaded parts: Reapply test torque and then remove from the fixture and examine per Section 3.4.
对于螺纹件：再次施加扭矩至试验扭矩，然后从夹具上取下，按3.4条检查。

- For non-threaded parts: Remove from the fixture and examine per Section 3.4.
对于无螺纹件：从夹具上取下，按3.4条检查。
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3.4 Pass/Fail Determination 试验通过/失败的判定

# [" ~# _4 c) r2 VVisually inspect the parts which have undergone the 48 hour test. The parts should be free of cracks or multi-piece fractures. If cracking or fracturing has occurred on one or more of the samples, the entire lot shall be rejected and scrapped (no rework of these parts is allowed). If none of the sample parts have cracked or fractured, the lot may be shipped.
目视检查经过48小时试验的零件。零件应无裂纹或破裂。如一个或多个样件出现裂纹或破裂，则整批零件判为不合格并报废（不允许对这些件进行返工）。如果这些样件上都没有裂纹或破裂，则该批零件可以交付。

3.5 Test Methods 试验方法
2 a) V0 b; R& k" A4 L* A# a& R
⑴.  Flat and coned washers pre-assembled or loose, should be tested on a fixture having an oversize clearance hole so that a high tensile stress is induced to the washer. Pre-assembled screw and washer, and nut and washer assemblies are to be loaded against a test plate, or spacer. The minimum and maximum hole diameter of the test plate or spacer must be with in 80% of the minimum and maximum outside diameter of the washer respectively. The thickness of the test plate, or spacer must be greater than the minimum washer thickness being tested. Loose washers are to be tested in the same manner. The minimum across flats dimension of the hex bolt or hex nut being used to test the loose washer must not be greater than 1.5 times the basic thread size. Five parts must be loaded to 80% of the ultimate strength of the test assembly as determined in Section 3.1.1 for the hydrogen embrittlement test.
    组合螺栓和组合螺母上的平垫圈或锥形垫圈，或非组合件用的平垫圈或锥形垫圈，应在具有较大孔径的通孔的夹具上进行试验，从而使垫圈承受较大的拉伸应力。螺栓和垫圈组合件以及螺母和垫圈的组合件，应被装配到试验圆板或衬套上。试验圆板或衬套的孔径的上下极限分别是垫圈外径的最大值和最小值的80%。试验圆板或衬套的厚度应大于被试验垫圈的最小厚度。非组合件用的垫圈应以同样方式进行试验。用于试验非组合用垫圈的六角螺栓或六角螺母的最小对边宽度不能大于垫圈内径所对应的螺纹公径直径的1.5倍。氢脆试验时，先按3.1.1条确定试验螺栓或组合螺栓的极限强度，再将5个垫圈装配到一起加载到的极限强度的80%。

3 x' T" h  r+ X⑵. Screws, bolts, or nuts without washers must be loaded against a test plate with a minimum diameter clearance hole equal to the nominal thread size plus 0.50mm for fasteners M6 (1/4 inch) and smaller, and plus 1.0mm for larger diameters.
4 [% o: w! d4 D0 B# ^9 o5 |无垫圈的螺钉、螺栓、或螺母应被装夹到具有较小孔径的通孔的试验圆板上进行试验，对于≤M6 (1/4 inch)的紧固件，试验圆板的孔径为公称螺纹直径加上0.50mm，对于＞M6 (1/4 inch)的紧固件，试验圆板的孔径为公称螺纹直径加上1.0mm 。

3.6 Suggested Fixturing Methods 推荐的装夹方法

The following suggestions are provided to assist in establishing the test load and method of test to induce high tensile stress for performing the hydrogen embrittlement test.

下列建议有助于确定氢脆试验的载荷，并使试验件上得到较高的拉伸应力。

⑴. Screws may be seated against a 4-degree wedge to represent a worst case assembly condition. A flat washer may be inserted between the screw and the wedge test plate to eliminate the effects of torque robbing features. Serrations, rings, etc. may prevent torquing the fastener to failure due to socket cam off or recess bit cam out. (NOTE: The washer I.D. should not be larger than 0.04 in (1.0 mm) over the major diameter of the screw.) The O.D. of the washer should be equal to or greater than the maximum flange diameter of the screw being tested.

可将螺栓固定在一个4°楔形垫圈上以模拟最恶劣的装配条件。可以在螺栓和楔形垫圈之间装入一个平垫圈来消除由于楔形垫圈而产生扭矩削弱的影响。由于套筒或内花形枪头容易滑脱出来而使紧固件无法扭断，扳拧工具上可做出锯齿形的凸起、环形等等以防止这种情况发生。（注：垫圈的内径不可大于螺栓或螺钉大径0.04英寸或1.0 mm），垫圈的外径应等于或大于被试螺栓的最大法兰直径。

⑵. Large diameter threaded fasteners may be lubricated to reduce the torque required to fail the fastener and establish the test torque. If lube is used, the same lube must be used and applied for the entire test.

确定试验扭矩时，对于一些大直径的螺纹紧固件，可使用润滑剂处理来减小紧固件的的失效扭矩。如果使用了润滑剂，则整个试验过程均需采用同种润滑剂。

⑶. Screws with internal drives which cannot be torqued to failure due to bit cam out or failure should be tested to the maximum torque obtainable without bit cam out or failure. This will be the test torque for the hydrogen embrittlement test for this type of fastener. The operator performing the test must use due diligence to apply sufficient pressure with the tool to prevent premature cam out.

内扳拧形式的螺钉试验时，由于花形扳拧头滑脱出来或内花形损坏而无法扭断的，应测出扳拧头滑脱前的最大扭矩或内花形损坏时的最大扭矩。这个扭矩就作为此种类型紧固件的氢脆试验扭矩。试验者应在工具上施加一定的轴向压力载荷而防止扳拧头过早滑脱。

⑷. Tapping screws may be tested using pre-threaded holes in test plates to achieve screw failures instead of thread strippage. Torsional strength testing of the fastener must still be performed where required.

自攻螺钉应装入带有螺纹孔的试验圆板上拧至螺钉损坏，而不是在螺纹测试条上进行。紧固件的扭断强度试验也应在规定的工装上进行。

⑸. Screws may be tested by applying torque to head of the screw or to a nut if a nut is used as part of the test set up.

对于螺钉的试验，可在螺钉头部施加扭矩，如果试验时用到了螺母，也可向螺母施加扭矩。

4
GENERAL INFORMATION 总论

Certain important information relative to this standard has been included in separate standards. To assure the processes submitted meet all of DaimlerChrysler requirements, it is mandatory that the requirements in the following standards be met.

本标准中某些重要信息是来自其他标准的。为使试验过程完全符合戴姆勒·克莱斯勒的要求，强制性要求达到下列标准的要求