标准编号:	DL/T 905-2016
中文名称:	汽轮机叶片、水轮机转轮焊接修复技术规程
英文名称:	Code of repair welding for blade of steam turbine and runner of hydroturbine
行业分类:	DL    电力行业标准
发布机构:	国家能源局
发布日期:	2016-08-16
实施日期:	2016-12-1
标准状态:	现行
替代旧标准:	DL/T 905-2004 汽轮机叶片焊接修复技术导则
翻译语言:	英文
文件格式:	PDF
中文字符数:	14000 字
翻译价格(元):	980.00 元
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.

This standard is modified in relation to DL/T 905-2004 Technical guide for repair welding of turbine blades in accordance with the Notice on issuing the development and revision plan of the second batch of professional standards of energy sector in 2013 (GUONENGKEJI [2013] No.526) issued by the National Energy Administration of the People's Republic of China.

This standard is prepared in accordance with the rules given in GB/T 1.1-2009 Directives for standardization—Part 1: Structure and drafting of standards.

This standard replaces DL/T 905-2004 Technical guide for repair welding of turbine blades. In addition to a number of editorial changes, the following technical changes have been made with respect to DL/T 905-2004:

——The application scope of the standard has been expanded, and the content of repair welding for hydroturbine runner has been added;

——The requirements for baking welding rod have been added;

——The requirements for wind speed and humidity in welding environment have been added;

——The requirements for monitoring preheating temperature before repair welding for blade of steam turbine have been added;

——The requirements for background current and peak current of pulsed argon tungsten-arc welding have been added;

——The requirements for repair process for hydroturbine runner have been added;

——The requirements for ultrasonic testing after repairing hydroturbine runner have been added;

——The requirements for the purity of argon gas have been modified;

——The requirements for grinding base metal before fitting up blades for welding have been modified，and the range of base metal to be ground has been specified;

——The requirements for welding materials, preheating and interlayer temperature and post-welding heat treatment recommended for repairing blade of steam turbine have been modified;

——The requirements for welding process during repair welding for blade of steam turbine have been modified.

This standard was proposed by the China Electricity Council (CEC).

This standard is under the jurisdiction of the Technical Committee on Power Station Welding of Standardization Administration of Power Industry.

This standard was firstly issued in 2004, and this edition is the first revision.

This standard replaces DL/T 905-2004 Technical guide for repair welding of turbine blades from the implementation date hereof.

Any comments or suggestions during the implementation of this standard may be fed back to the Standardization Center of the China Electricity Council (No.1, 2nd Lane, Baiguang Road, Beijing, 100761, China).

Code of repair welding for blade of steam turbine and runner of hydroturbine

1 Scope

This standard specifies the technical conditions and inspection requirements for repair welding for blades of steam turbine and runners of hydroturbine.

This standard is applicable to the repair welding of steam turbine blades, blade shrouds and lacing wires in fossil-fuel power plants, and the repair welding of hydroturbine runners in hydropower plants.

2 Normative references

The following referenced documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 3323 Radiographic examination of fusion welded joints in metallic materials

GB/T 11345 Non-destructive testing of welds—Ultrasonic testing—Techniques, testing levels, and assessment

GB/T 29712 Non-destructive testing of welds—Ultrasonic testing—Acceptance levels

DL/T 438 The technical supervision codes for metal in fossil-fuel power plant

DL/T 675 Examination codes for qualification of non-destructive testing personal of electric power industry

DL/T 679 Code for welder technical qualification

DL/T 819 The code of the welding heat treatment for power plant

DL/T 868 Qualification standard for welding procedures

DL/T 869 The code of welding for power plant

DL/T 1318 Technical supervision code for hydroelectric power plant metals

JB/T 3223 Welding consumables quality management procedures

NB/T 47013.4 Nondestructive testing of pressure equipment—Part 4: Magnetic particle testing

NB/T 47013.5 Nondestructive testing of pressure equipment—Part 5: Penetrant testing

SJ/T 10743 Ceriated tungsten electrodes for inert gas arc welding and plasma welding and cutting



3 General rules

3.1 Welding personnel

3.1.1 General requirements

Welding personnel include welding technicians, welders, welding heat treatment personnel and inspectors. All types of personnel shall meet the provisions of this standard in addition to the relevant requirements of DL/T 869.

3.1.2 Welding technicians

3.1.2.1 Welding technicians shall be technicians from the welding major or similar majors with the title of engineer or above, and shall be in charge of the welding process test and the repair welding for blade of steam turbine and runner of hydroturbine.

3.1.2.2 Welding technicians shall know the operating conditions of the parts to be repaired and the causes of defects, master the welding performance of the materials of the parts to be repaired, and be acquainted with and conscientiously implement this standard.

3.1.2.3 Welding technicians are responsible for determining the inspection position, recording, checking and sorting out the welding data and compiling the technical summary.

3.1.3 Welders

3.1.3.1 Welders shall be qualified as Class I welders as specified in DL/T 679 or as approved by the owner.

3.1.3.2 Before welding, welders shall practice welding according to the operation instruction by simulating the actual onsite situation using the parts of the same materials and types as those to be repaired. During welding, welders shall strictly abide by the welding process plan or operation instruction, and report problems, if any, to the welding technicians in time (handling without permission is prohibited).

3.1.4 Welding heat treatment personnel

3.1.4.1 Welding heat treatment personnel shall perform duties in accordance with the requirements of DL/T 819.

3.1.4.2 Welding heat treatment personnel shall strictly implement the requirements for welding heat treatment in the welding process plan or operation instruction, and timely sort out and summarize welding heat treatment data.

3.1.5 Welding inspectors

3.1.5.1 Welding inspectors include non-destructive inspectors and physical and chemical inspectors.

3.1.5.2 Non-destructive inspectors shall have an inspection qualification of Class II or above specified in DL/T 675 or issued by other institutions, record the original defects of the parts to be repaired before welding, inspect the repaired parts, and issue the inspection report in time.

3.1.5.3 Physical and chemical inspectors shall carry out inspection according to the requirements of this standard and the welding process plan, and issue the inspection report in time.

3.2 Welding process test

3.2.1 Before welding, welding process tests shall be carried out applying corresponding performance requirements and welding process to be adopted for the parts to be repaired, and the test results shall be qualified.

3.2.2 Simulated welding test, destructive test or other tests specified in DL/T 868 may be carried out when necessary.

3.2.3 The welding process plan or operation instruction shall be prepared on the basis of the process test result and the actual situation.

3.3 Welding materials and management

3.3.1 Welding materials to be used shall be provided with quality certificate issued by the manufacturing plant. The storage and usage management of welding materials shall comply with the rules of JB/T 3223, and when necessary, welding materials shall be re-inspected and only those qualified can be used.

3.3.2 The welding materials used shall meet the requirements of corresponding standards. Ceriated tungsten electrode or lanthanated tungsten electrode shall be used in argon tungsten-arc welding. Ceriated tungsten electrode used shall meet the requirements of SJ/T 10743, and the purity of argon gas used shall be 99.99% or above.

3.3.3 Welding rods shall be baked in accordance with the requirements of the instructions before use. Do not re-bake the welding rod more than twice. For the convenience of usage, put the welding rod in a dedicated insulation barrel of 80°C~110°C.

3.4 Equipment for repair welding

3.4.1 Welding equipment, carbon arc gouging equipment, welding heat treatment equipment, welding rod drying equipment, physical and chemical inspection equipment and non-destructive testing instruments shall be safe and reliable with stable parameters and flexible adjustability, meeting the corresponding technical requirements.

3.4.2 Use DC welding power supply with functions of automatic arc-ignition and automatic arc-extinguishing by attenuation. DC power supply with pulse function should be selected for manual argon tungsten-arc welding and gas-shielded welding.

3.4.3 Where there are metrological verification requirements, the equipment shall be in the validity period of the verification.

3.5 Safety requirements and environment conditions

3.5.1 Welding operation shall comply with the relevant rules of safety.

3.5.2 The ambient temperature for welding operation shall not be lower than 5°C. The ambient wind speed for gas-shielded welding shall not be more than 2 m/s, and that for other welding methods shall not be more than 8 m/s. The relative ambient humidity shall not be more than 80%.

4 Preparation before repair welding

4.1 Confirmation of material and determination of defect location

4.1.1 Before repair, the chemical composition and properties of the base metal of the parts to be repaired shall be confirmed on the basis of manufacturing drawings or other technical documents provided by the manufacturing plant. Sample the metal base for chemical composition analysis when necessary.

4.1.2 Before repair, check the distribution and size of defects, determine the types of defects and make records. Ultrasonic testing, magnetic particle testing or penetrant testing should be adopted during checking.

4.1.3 If the welding process test result shows that the performance after repair fails to meet the requirements, the repair welding for blade of steam turbine and runner of hydroturbine shall not be carried out. When the crack defect is within 2/3 of the length from the blade root to the blade tip, the repair welding for blade of steam turbine should not be carried out.

4.2 Removal of defects

4.2.1 Superficial defects shall be removed by mechanical means.

4.2.2 To remove crack defects on hydroturbine runner, mechanical means or carbon arc gouging may be adopted. When using carbon arc gouging method to remove the crack, it is necessary to preheat the defect area to the temperature suitable for the material of the parts to be repaired. It is suggested to mark at a position 1 mm away from the crack tip and open a crack arrest hole there before remove the crack from the crack tip. After gouging, the carburized layer shall be polished until metallic luster is revealed.

4.2.3 For repairable steam turbine blades, defects shall be removed by mechanical means. If there is Stellite alloy sheet or other corrosion-proof alloy layer on the back of the blade, the alloy sheet or layer at the crack shall be cleaned before removal of defect.

4.2.4 After the defect is removed, an inspection shall be carried out to confirm that the defect has been eliminated.

4.3 Groove and fitting

4.3.1 When fitting broken blades, special clamp shall be used, and there shall not be misalignment and bending.

4.3.2 When there are penetrating cracks, double-sided grooves should be adopted. The groove angle and fitting clearance shall be determined according to the thickness of the blades on the principles of easy operation, full welding and minimized filling.

4.3.3 The materials selected for repair should match the original materials, and pass the physical and chemical inspection. Before fitting, the line shape of the blade shall be processed in advance until it is basically consistent with the original blade, and a certain machining allowance shall be left.

4.3.4 Before fitting, the groove and the base metal within 20 mm to the groove shall be polished until metallic luster is revealed.

4.3.5 The power supply ground wire used for welding shall be directly connected with the welded parts, firmly clamped and in good contact. Do not connect the ground wire to the bracket of the rotor.

5 Repair welding process

5.1 Repair welding process for steam turbine blade

5.1.1 Welding method

Argon tungsten-arc welding is preferred, and shielded metal arc welding may also be used.

5.1.2 Welding materials

5.1.2.1 Welding materials shall match blade materials. Under special circumstances, iron-based or nickel-based austenitic heterogeneous welding materials may be used.

5.1.2.2 See Table 1 for welding materials and welding heat treatment process recommended for repairing blade of steam turbine. To use special welding materials, welding process test of these materials shall be carried out, and the test result shall meet the design requirements.

Table 1 Welding materials and welding heat treatment process recommended for repairing blade of steam turbine

Blade material Welding wire model Welding rod model Preheating and interlayer temperature

(°C) Post-weld heat treatment

Temperature

(°C) Heat preservation time

(h)

12Cr13, 20Cr13 H12Cr13 E410 -15 200~250 680~720 0.5

H08Cr19Ni10Ti

H08Cr20Ni10Nb E347 -15 100~150

12Cr02Mo H08Cr19Ni10Ti

H08Cr20Ni10Nb E410 -15 100~150 680~720 0.5

05Cr17Ni4Cu4Nb H00Cr17Ni4Cu4Nb — 100~150 600~650 0.5



5.1.3 Preheating and interlayer temperature

5.1.3.1 The resistance-heating method should be adopted during preheating. The heating width, heat preservation and temperature measurement shall comply with the relevant rules of DL/T 819.

5.1.3.2 When preheating with oxygen-acetylene neutral flame, the preheating range is 50 mm on both sides of the groove. When preheating, the flame core shall be 10 mm or further away from the workpiece. The heating shall be even. It is recommended to monitor the preheating temperature at the position 50 mm away from the edge of the groove by a far infrared thermometer or other non-contact temperature measurement methods.

5.1.3.3 When measuring temperature by thermocouple, it is forbidden to fix the thermocouple by welding (including welding with an energy storage welder).

5.1.3.4 Recommended preheating and interlayer temperatures are shown in Table 1.

5.1.4 Welding position and welding sequence

5.1 4.1 The welding position shall be as horizontal as possible.

5.1.4.2 For blades broken completely, weld from the thick side to the thin side. For unbroken blades, weld from the inner side to the edge of the blade. For the thin edge of the blade, welder may adopt the welding process by welding on one side of the groove, by which welds will be formed on both sides of the groove.

5.1.5 Welding process

5.1.5.1 The recommended argon tungsten-arc welding process is as follows:

a) The welding wire with diameter less than or equal to 2.0 mm should be selected, and the recommended welding current is 50 A ~ 70 A. The background current of pulsed argon tungsten-arc welding is 30 A ~ 50 A, and the peak current is 90 A ~ 110 A.

b) During welding, the weld shall be provided with delayed protection, and the back of the weld shall be treated with argon-filled protection.

c) Multi-layer and multi-pass welding should be used.

d) The weld reinforcement after welding shall be controlled within 1 mm.

5.1.5.2 The recommended shielded metal arc welding process is as follows:

a) The welding rod with diameter less than or equal to 2.5 mm should be selected, and the recommended welding current is 60 A ~ 90 A.

b) Multi-layer and multi-pass welding should be adopted. The width of the weld bead shall not exceed 3 times of the diameter of the welding rod, and the thickness shall not exceed 3 mm.

c) During double-sided welding, gouge the root.

d) The weld reinforcement after welding shall be controlled around 1 mm.

5.1.6 Post-weld heat treatment

5.1.6.1 After welding, the blades shall be coated and cooled slowly in time, and post-weld heat treatment shall be carried out immediately when the temperature of the weld core drops to about 100 °C.

5.1.6.2 Resistance-heating should be used for post-weld heat treatment, and the blade should be in the vertical position as much as possible during heat treatment.

5.1.6.3 The hot end of the thermocouple shall be close to the center of the weld, but the thermocouple shall not be fixed by welding (including welding with an energy storage welder).

5.1.6.4 The heating width is 30 mm ~ 60 mm on each side of the weld.

5.1.6.5 During heat treatment, remove the heater and thermal insulation device after the time for heat treatment is over, and let the blade be air-cooled.

Foreword i
1 Scope
2 Normative references
3 General rules
3.1 Welding personnel
3.2 Welding process test
3.3 Welding materials and management
3.4 Equipment for repair welding
3.5 Safety requirements and environment conditions
4 Preparation before repair welding
4.1 Confirmation of material and determination of defect location
4.2 Removal of defects
4.3 Groove and fitting
5 Repair welding process
5.1 Repair welding process for steam turbine blade
5.2 Repair process for hydroturbine runner
6 Quality inspection
6.1 Inspection contents
6.2 Appearance inspection
6.3 Non-destructive testing
6.4 Hardness and metallographic inspection
6.5 Others
7 Weld repair
8 Technical documents

ICS 27.100
F 20
备案号：56223-2016
DL
中华人民共和国电力行业标准
DL/T 905—2016
代替DL/T 905—2004
______________________________________________________________________


汽轮机叶片、水轮机转轮焊接
修复技术规程
Code of repair welding for blade of steam turbine and runner of hydroturbine




2016-08-16发布 2016-12-01实施
国家能源局 发布
前言
本标准是根据《国家能源局关于下达2013年第二批能源领域行业标准制(修)订计划的通知》(国能科技(2013)526号)的要求安捧，对DL/T 905—2004《汽轮机叶片焊接修复技术导则》进行修订的。
本标准按照GB/T 1.1—2009《标准化工作导则 第1部分：标准的结构和编写》给出的规则起草。
本标准代替DL/T 905—2004《汽轮机叶片焊接修复技术导则》。本标准与DL/T 905—2004相比，除编辑性修改外，主要技术变化如下：
——扩大了标准的适用范围，增加了水轮机转轮焊接修复的内容；
——增加了焊条烘焙的要求；
——增加了焊接环境风速和湿度的要求；
——增加了汽轮机叶片焊接修复预热温度监测的要求；
——增加了脉冲无极氩弧焊基值电流和峰值电流的要求；
——增加了水轮机转轮修复工艺的要求；
——增加了水轮机转轮修复后超声波检测的要求；
——修改了氩气纯度的要求；
——修改了焊接组对前母材打磨的要求，明确了母材打磨范围；
——修改了汽轮机叶片修复推荐的焊接材料、预热及层间温度、焊后热处理的要求；
——修改了汽轮机叶片焊接修复焊接工艺的要求。
本标准由中国电力企业联合会提出。
本标准由电力行业电站焊接标准化技术委员会归口。
本标准首次发布日期为2004年，本次为第一次修订。
本标准自实施之日起替代DL/T 905—2004《汽轮机叶片焊接修复技术导则》。
本标准在执行过程中的意见或建议反馈至中国电力企业联合会标准化管理中心(北京市白广路二条一号，邮编：100761)。
汽轮机叶片、水轮机转轮焊接修复技术规程
1 范围
本标准规定了汽轮机叶片、水轮机转轮缺陷焊接修复的技术条件及检验要求。
本标准适用于火力发电厂汽轮机叶片、叶片围带及拉筋的焊接修复，以及水力发电厂水轮机转轮的焊接修复。
2 规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是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。
GB/T 3323 金属熔化焊焊接接头射线照相
GB/T 11345 焊缝无损检测 超声检测 技术、检测等级和评定
GB/T 29712 焊缝无损检测 超声检测 验收等级
DL/T 438 火力发电厂金属技术监督规程
DL/T 675 电力工业无损检测人员资格考核规则
DL/T 679 焊工技术考核规程
DL/T 819 火力发电厂焊接热处理技术规程
DL/T 868 焊接工艺评定规程
DL/T 869 火力发电厂焊接技术规程
DL/T 1318 水电厂金属技术监督规程
JB/T 3223 焊接材料质量管理规程
NB/T 47013.4 承压设备无损检测 第4部分：磁粉检测
NB/T 47013.5 承压设备无损检测 第5部分：渗透检测
SJ/T 10743 惰性气体保护电弧焊和等离子焊接、切割用钨铈电极
3 一般规定
3.1 焊接工作人员
3.1.1 一般要求
焊接工作人员包括焊接技术人员、焊工、焊接热处理人员和焊接检验人员。各类人员除应满足DL/T 869的相关要求外，还随符合本标准的规定。
3.1.2 焊接技术人员
3.1.2.1 焊接技术人员应由工程师及以上职称的焊接或相近专业的人员担任，并主持焊接工艺试验和汽轮机叶片、水轮机转轮的焊接修复工作。
3.1.2.2 焊接技术人员应了解修复件的运行工况和缺陷产生的原因，掌握修复件材料的焊接性能，熟悉并认真执行本标准。
3.1.2.3 焊接技术人员负责确定检验部位，记录、检查、整理焊接资料，编制技术总结。
3.1.3 焊工
3.1.3.1 焊工应具备DL/T 679规定的I类焊工资格，或具备业主认可的资质。
3.1.3.2 焊工焊接前根据作业指导书按修复件的材质、类型模拟现场实际情况进行训练；施焊时严格按照焊接工艺方案或作业指导书焊接，出现问题及时向焊接技术人员汇报，不得擅自处理。
3.1.4 焊接热处理人员
3.1.4.1 焊接热处理人员应按照DL/T 819的相关规定履行职责。
3.1.4.2 焊接热处理人员应严格执行焊接工艺方案或作业指导书中有关焊接热处理的要求，及时整理和汇总焊接热处理资料。
3.1.5 焊接检验人员
3.1.5.1 焊接检验人员包括无损检测人员和理化检验人员。
3.1.5.2 无损检测人员应具各DL/T 675规定的或其他机构颁发的II级及以上检验资格，应记录待修复件焊接前的原始缺陷，对修复后的焊件进行检验，及时出具检验报告。
3.1.5.3 理化检验人员应按照本标准和焊接工艺方案的要求进行检验，及时出具检验报告。
3.2 焊接工艺试验
3.2.1 施焊前应结合修复件的性能要求、拟采用的焊接工艺进行相应的焊接工艺试验并合格。
3.2.2 必要时，可进行焊接模拟试验、破坏性试验或DL/T 868规定的其他试验。
3.2.3 依据工艺试验结果和实际情况编制焊接工艺方案或作业指导书。
3.3 焊接材料及管理
3.3.1 使用的焊接材料应有制造厂的质最合格证书。焊接材料的存放、使用管理应符合JB/T 3223的规定，必要时进行复验，符合质量要求时方可使用。
3.3.2 使用的焊接材料应满足相应标准的要求。钨极氩弧焊宜使用钨铈电极或钨镧电极，钨铈电极应符合SJ/T 10743的规定，使用的氩气纯度应达到99.99％及以上。
3.3.3 焊条在使用前应按说明书的要求进行烘焙，重复烘焙不应超过2次，使用时应装入温度为80℃～110℃的专用保温桶内，随用随取。
3.4 焊接修复用设备
3.4.1 焊接设备、碳弧气刨设备、焊接热处理设备、焊条烘干设备、理化检验设备和无损检测仪器应参数稳定、调整灵活、安全可靠，并满足相应的技术要求。
3.4.2 应选用直流焊接电源，并具有自动引弧和衰减熄弧功能，手工钨极氩弧焊及气体保护焊宜选用带脉冲功能的直流电源。
3.4.3 有计量检定要求时，应在检定有效期内。
3.5 安全要求和环境条件
3.5.1 焊接工作应遵守安全工作的有关规定。
3.5.2 焊接工作环境温度不得低于5℃；气体保护焊环境风速应不大于2m/s，其他焊接方法环境风速应不大于8m/s；环境相对湿度应不大于80％。
4 修复前的准备
4.1 材质确认与缺陷位置的确定
4.1.1 修复前应以厂家提供的制造图纸或其他技术文件为依据，确认修复件母材的化学成分和性能。必要时，取样进行化学成分分析。
4.1.2 修复前应检查缺陷的分布情况和尺寸，确定缺陷的类型并做好记录。宜采用超声波检测、磁粉检测或渗透检测方法检查。
4.1.3 焊接工艺试验结果显示修复后性能不满足要求时，不应进行汽轮机叶片或水轮机转轮的焊接修复；当裂纹缺陷处于汽轮机叶根至叶片顶端长度2/3范围内时，不宜进行汽轮机叶片的焊接修复。
4.2 缺陷清除
4.2.1 当缺陷为浅表性缺陷时，应采用机械方式清除缺陷。
4.2.2 当水轮机转轮缺陷为裂纹时，可采用机械方式或碳弧气刨方式清除缺陷。使用碳弧气刨方法清除裂纹时，需先将待清除缺陷区域预热至修复件材质的焊接预热温度，宜在距离裂纹尖端1mm位置标记并开设止裂孔，然后从裂纹尖端起进行刨除。气刨后应打磨去除渗碳层，直至露出金属光泽。
4.2.3 对可修复的汽轮机叶片，应采用机械方式清除缺陷。如叶片背面有司太立合金片或其他防水蚀的合金层，清除前应先将裂纹处的合金片或合金层清除干净。
4.2.4 缺陷清除后，应进行检查，确认缺陷已消除干净。
4.3 坡口与组对
4.3.1 已经断裂的叶片组对时，应采用专用的夹具，不应出现错口和弯折现象。
4.3.2 存在贯穿性裂纹缺陷时，宜采用双面坡口，应根据叶片的厚度确定坡口角度和组对间隙，原则是易操作、保证焊透、填充量少。
4.3.3 新配置的材料宜与原材质相当，并经理化检验台格；叶片的线型应预先加工成与原叶片基本一致后再进行组对，且留有一定的加工余量。
4.3.4 组对前，应将坡口及其周围20mm范围内的母材打磨干净，直至露出金属光泽。
4.3.5 焊接电源地线要与被焊部件直接相连，且夹持牢固、接触良好，不得将地线连接在转子的支架上。
5 焊接修复工艺
5.1 汽轮机叶片修复工艺
5.1.1 焊接方法
优先选用钨极氩弧焊，也可采用焊条电弧焊。
5.1.2 焊接材料
5.1.2.1 焊接材料应与叶片材质相当，特殊情况下，也可采用铁基或镍基的奥氏体异质焊接材料。
5.1.2.2 汽轮机叶片修复推荐的焊接材料及焊接热处理工艺见表1。使用专用焊接材料时，应进行焊接工艺试验，试验结果满足设计要求。
表1 汽轮机叶片修复推荐的焊接材料及焊接热处理工艺
叶片材质 焊丝型号 焊条型号 预热及层间温度℃ 焊后热处理
温度℃ 保温时间h
12Cr13、20Cr13 H12Cr13 E410-15 200～250 680～720 0.5
H08Cr19Ni10Ti
H08Cr20Ni10Nb E347-15 100～150
12Cr02Mo H08Cr19Ni10Ti
H08Cr20Ni10Nb E410-15 100～150 680～720 0.5
05Cr17Ni4Cu4Nb H00Cr17Ni4Cu4Nb — 100～150 600～650 0.5
5.1.3 预热及层间温度
5.1.3.1 宜采用电阻加热方法预热，加热宽度、保温和测温要求按DL/T 819相关规定执行。
5.1.3.2 采用氧-乙炔中性焰预热时，预热范围为坡口两侧各50mm，预热时火焰焰心距离工件10mm以上，加热要均匀，宜采用远红外测温仪或其他非接触式测温方法在距离坡口边缘50mm处监测预热温度。
5.1.3.3 采用热电偶方式测温时，禁止采用焊接方法(包括使用储能焊机焊接)固定热电偶。
5.1.3.4 推荐的预热及层间温度见表1。
5.1.4 焊接位置与焊接顺序
5.1.4.1 焊接位置应尽量处于水平位置。
5.1.4.2 已全部断裂的叶片宜由厚侧向薄侧施焊；未断裂叶片从叶片内向边缘施焊；叶片的薄边处可采用单面焊双面成型工艺。
5.1.5 焊接工艺
5.1.5.1 钨极氩弧焊推荐工艺如下：
a) 宜选用直径小于或等于2.0mm的焊丝，推荐的焊接电流为50A～70A；脉冲钨极氩弧焊基值电流30A～50A，峰值电流90A～110A。
b) 焊接过程中，焊缝应延迟保护，焊缝背面进行充氩保护。
c) 宜采用多层多道焊。
d) 焊后焊缝余高控制在1mm以内。
5.1.5.2 焊条电弧焊推荐工艺如下：
a) 宜选用直径小于或等于2.5mm的焊条，推荐的焊接电流为60A～90A。
b) 宜采用多层多道焊，焊道宽度不超过焊条直径的3倍，厚度不超过3mm。
c) 双面焊时，背部应清根。
d) 焊后焊缝余高控制在1mm左右。
5.1.6 焊后热处理
5.1.6.1 焊接后应及时将叶片包敷缓冷，待焊缝中心温度降至100℃左右时立即进行焊后热处理。
5.1.6，2 焊后热处理宜使用电阻加热，热处理时叶片应尽最处于垂直位置。
5.1.6.3 热电偶的热端要紧贴焊缝中心，但不得以焊接方法(包括使用储能焊机焊接)固定热电偶。
5.1.6.4 加热宽度为焊缝每侧30mm～60mm。
5.1.6.5 热处理到达保温时间后拆除加热器和保温装置，让叶片空冷。
5.2 水轮机转轮修复工艺
5.2.1 焊接方法
5.2.1.1 根据现场修复条件，可采用钨极氩弧焊、焊条电弧焊、熔化极气体保护焊或其组合焊方法。
5.2.1.2 点状缺陷或面积较小的表面缺陷宜采用钨极氩弧焊进行修复，焊接工作量较大的缺陷宜选择手工焊条电弧焊或熔化极气体保护焊进行修复。
5.2.2 焊接材料
5.2.2.1 优先选用抗裂性好、性能与母材相当的焊接材料。
5.2.2.2 对水流含沙量较大的转轮修复时，若现场不具备热处理条件，宜先使用奥氏体焊接材料焊接，再使用马氏体焊接材料等焊接材料焊接盖面层，盖面层厚度不小于8mm。
5.2.2.3 点状表面缺陷修复时若采用奥氏体不锈钢焊接材料，应进行预热、后热；无须进行焊后热处理。
5.2.2.4 水轮机转轮修复推荐的焊接材料及焊接热处理工艺见表2。使用专用焊接材料时，焊接材料熔敷金属化学成分、力学性能应满足表3和表4的规定。
表2 水轮机转轮修复推荐的焊接材料及焊接热处理工艺
转轮材质 焊接方法 焊接材料 预热及层间温度
℃ 后热 焊后热处理
温度
℃ 保温时间
h 温度
℃ 保温时间
h
ZG04Cr13Ni5Mo
ZG0Cr13Ni4Mo 熔化极气体保护焊 ER410NiMo 110～170 250～300 ≥1 560～590 见5.2.5.4
焊条电弧焊 E410NiMo 110～170 560～590
钨极氩弧焊 ER410NiMo 110～170 560～590
表3 推荐的焊接材料熔敷金属化学成分(质量分数) 单位：％
焊材 C Si Mn S P Cr Ni Mo
焊丝 ≤0.04 ≤1.0 1.0～3.5 ≤0.015 ≤0.025 16.0～19.0 5.0～7.0 1.0～1.5
焊条 ≤0.05 ≤0.6 ≤3.5 ≤0.015 ≤0.025 16.0～18.0 5.0～7.0 1.0～1.5
表4 推荐的焊接材料熔敷金属力学性能
焊材 状态 力学性能
抗拉强度
MPa 断后伸长率
％ 冲击吸收能量(室温)Akv
J
焊丝 焊态 ≥750 ≥16 ≥50
焊条 焊态 ≥750 ≥16 ≥50
5.2.3 预热及层间温度
5.2.3.1 宜采用电阻加热方法预热，加热宽度、保温和测温要求参照DL/T 819相关规定执行。
5.2.3.2 采用氧-乙炔中性焰预热时，预热范围为坡口两侧各50mm，预热时火焰焰心距离工件10mm以上，加热要均匀，宜采用远红外测温仪或其他非接触式测温方法在距离坡口边缘50mm处监测预热温度。
5.2.3.3 水轮机转轮补焊修复时推荐的预热及层间温度见表2。
5.2.4 焊接工艺
5.2.4.1 钨极氩弧焊推荐工艺如下：
a) 宜选用直径大于或等于1.8mm的焊丝，推荐的焊接电流为80A～120A；脉冲钨极氩弧焊基值电流50A～60A，峰值电流110A～140A。
b) 宜采用多层多道焊。
c) 焊后焊缝进行随形打磨处理。
5.2.4.2 焊条电弧焊推荐工艺如下：
a) 宜选用直径大于或等于3.2mm的焊条，焊接电流按焊接工艺试验确定的参数执行。
b) 宜采用多层多道焊，焊道宽度不超过焊条直径的3倍，厚度不超过4mm。
c) 双面焊时，背部应清根，背部清根后应进行表面渗透检测，检测合格后方可进行背面焊接。
d) 焊后焊缝进行随形打磨处理。
5.2.4.3 熔化极气体保护焊推荐工艺如下：
a) 宜选用φ1.2mm规格焊丝，焊接电流按焊接工艺试验确定的参数执行。
b) 宜采用多层多道焊接，焊道宽度不宜超过15mm。
c) 双面焊时，背部应清根，背部清根后应进行表面渗透检测，检测合格后方可进行背面焊接。
d) 焊后焊缝进行随形打磨处理。
5.2.5 后热与焊后热处理
5.2.5.1 水轮机转轮出现大面积缺陷时，宜返厂修复，并进行整体热处理。
5.2.5.2 少量修复或不便于返厂处理时，焊接后应将修复区域包覆缓冷。
5.2.5.3 后热相关要求如下：
a) 补焊深度小于或等于38mm或补焊面积小于或等于4000mm2时，进行后热后，可不进行焊后热处理。
b) 后热宜采用电加热或中性火焰加热方式，加热范围为焊缝每侧不少于50mm～100mm。
c) 后热加热与测温要求参照DL/T 819规定执行。
d) 推荐的后热参数见表2。
5.2.5.4 焊后热处理相关要求如下；
a) 对于补焊深度超过38mm或者补焊面积超过4000mm2的焊缝，应进行焊后热处理。
b) 焊后热处理宜采用电加热方式，加热及冷却速度不超过150℃/h。
c) 当焊缝厚度不超过50mm时，焊后热处理保温时间按照每25mm厚度1h计算，最少保温时间30min。
d) 当焊缝厚度超过50mm时，保温时间按照以下公式计算：

式中：
t——保温时间，h；
δ——焊缝厚度，mm。
e) 热处理到达保温时间后，停止加热，让焊件缓冷。
5.2.5.5 不具备进行焊后热处理的条件时，应采取锤击、超声冲击等措施降低焊接残余应力。
6 质量检验
6.1 检验内容
6.1.1 补焊工作完成后，应先进行修磨，再进行质量检验。
6.1.2 检验项目包括外观检查和无损检测。图纸或技术文件有硬度和金相检验要求时，需进行硬度和金相检验。
6.2 外观检查
6.2.1 焊缝不应有咬边、错口、凹陷、裂纹、未熔合、气孔和夹渣等表面缺陷。
6.2.2 水轮机转轮修复后，过流表面质量应满足图纸或技术文件的要求。
6.2.3 修复后变形量应满足汽轮机、水轮机安全运行的要求。
6.3 无损检测
6.3.1 表面无损检测
6.3.1.1 修复后，应对修复焊件进行渗透检测或磁粉检测。渗透检测、磁粉检测方法应分别按照NB/T 47013.5、NB/T 47013.4规定要求进行。
6.3.1.2 渗透或磁粉检测时，焊缝及热影响区不得有缺陷显示。
6.3.2 内部无损检测
6.3.2.1 汽轮机叶片修复后，应采用射线检测方法对焊缝进行内部质量检验。根据叶片修复处的位置和厚度变化，射线检测时可在叶片两侧分段进行，也可采用厚度补偿块或双胶片技术进行检验。
6.3.2.2 汽轮机叶片修复焊缝在进汽和出汽边15mm范围内不得有任何缺陷，其他部位应达到GB/T 3323规定的I级质量要求。
6.3.2.3 水轮机转轮修复后，应采用超声波检测方法对焊缝进行内部质量检验。检验按GB/T 11345规定的灵敏度为技术1级，检测等级按B级进行，焊缝质量应满足GB/T 29712规定的2级验收要求。
6，4 硬度和金相检验
6.4.1 有要求时，应对焊缝、热影响区进行硬度、金相检验，并做好记录，存档备查。
6.4.2 焊缝和热影响区的金相组织检验应采用复型检验或其他非破坏性检验方法，不允许存在显微裂纹、过热组织。
6.5 其他
焊接修复后经质量检验合格的汽轮机叶片、水轮机转轮应移交专业人员进行其他项目的检测。
7 焊缝返修
7.1 经检验不合格的焊缝允许返修，但汽轮机叶片返修次数不超过一次。
7.2 返修技术要求、返修工艺和检验要求按本标准的有关条款执行。
8 技术文件
8.1 焊接技术文件应及时编制和存档，属金属技术监督规程管理的焊接技术文件应分别符合DL/T 438、DL/T 1318的相关规定。
8.2 焊接技术文件的内容包括：
a) 焊接材料质量证明书。
b) 焊接工作人员资格证书。
c) 原始缺陷记录和坡口图。
d) 焊接工艺试验记录、焊接工艺方案或作业指导书。
e) 焊接记录、焊接热处理记录、焊接质量检验报告。
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