T∕CNS 4-2018 核電廠金屬材料高溫高壓水中腐蝕疲勞試驗方法

1、ICS 77.040.10H 22標準T/CNS 42018核電廠金屬材料局溫局壓水中腐蝕疲勞試驗方法Test method for corrosion fatigue in high temperature pressurized water ofmetallic materials for nuclear power plants2018-03-15 發(fā)布2018-05-30 實施中國核學會 發(fā)布T/CNS 42018目 次tuW Ii Mffl l2規(guī)范性引用文件13 術(shù)語和定義 14 試驗儀器和設(shè)備15 試樣制備和要求36 試驗條件和步驟 67 數(shù)據(jù)處理78 質(zhì)量保證79試驗報告7T/

2、CNS 42018本標準按照GB/T 1.12009給出的規(guī)則起草。本標準由中國核學會提出。本標準由核工業(yè)標準化研究所歸口。本標準起草單位：中國科學院金屬研究所、核工業(yè)標準化研究所、國家電投集團科學技術(shù)研究院、中 國核動力研究設(shè)計院、上海交通大學。本標準主要起草人：韓恩厚、譚季波、吳欣強、張宏偉、白亞奎、王家貞、姜峨、杜東海。I學兔兔標準下載學兔兔標準下載T/CNS 42018核電廠金屬材料高溫高壓水中腐蝕疲勞試驗方法1范圍本標準規(guī)定了核電廠高溫高壓水條件下金屬材料試樣軸向應變和位移控制腐蝕疲勞試驗的方法和 相關(guān)技術(shù)要求。本標準適用于具有一定標距長度的圓形、矩形橫截面試樣在360 °

3、0以下水介質(zhì)中軸向應變和位移 控制腐蝕疲勞試驗。產(chǎn)品構(gòu)件和其他特殊形狀試樣的高溫高壓水疲勞試驗可參照本標準執(zhí)行。2規(guī)范性引用文件下列文件對于本文件的應用是必不可少的。凡是注日期的引用文件，僅注日期的版本適用于本文 件。凡是不注日期的引用文件，其最新版本（包括所有的修改單）適用于本文件。GB/T 150.42011壓力容器 第4部分：制造、檢驗和驗收GB/T 30752008金屬材料疲勞試驗軸向力控制方法GB/T 152482008金屬材料軸向等幅低循環(huán)疲勞試驗方法GB/T 20120.12006金屬和合金的腐蝕腐蝕疲勞試驗第1部分:循環(huán)失效試驗3術(shù)語和定義GB/T 152482008、GB/T

4、 20120.12006和GB/T 30752008界定的以及下列術(shù)語和定義適用 于本文件。3.1疲勞壽命 fatigue life峰值拉應力下降至最大峰值拉應力的75%所對應的循環(huán)周次。3.2應變速率 strain rate應變范圍的兩倍與頻率的乘積。4試驗儀器和設(shè)備4.1高壓釜4.1.1高壓釜釜體、釜蓋應采用不銹鋼或鎳基合金等耐蝕合金制造。釜體一般為整體，特殊情況下允 許施焊，但應進行無損檢測。4.1.2釜體與釜蓋之間及釜上引出的各測試孔均應具有良好的密封性能，在試驗過程中不應有泄漏 現(xiàn)象。4.1.3可以模擬典型輕水堆核電站服役循環(huán)水環(huán)境，可在360 °C、20 MPa以下環(huán)境中

5、長期穩(wěn)定運行。 4.1.4高壓釜應設(shè)有安全保護裝置，并定期檢查安全保護裝置的可靠性。學兔兔標準下載T/CNS 420184.1.5應參照GB/T 150.42011的規(guī)定對釜體、釜蓋等高溫承壓構(gòu)件進行無損檢測，經(jīng)檢測合格后方 可使用。4.1.6試樣架宜采用耐高溫耐腐蝕材料制造，如采用奧氏體不銹鋼、鎳基合金等材料制成。4.1.7圖1給出了推薦采用的高溫高壓循環(huán)水系統(tǒng)和高壓釜的結(jié)構(gòu)示意圖。4.1.8推薦采用的高壓釜應配備有相應的外部冷卻水循環(huán)系統(tǒng)，以保護位移傳感器、力傳感器、密封圈 及其他不耐高溫試驗部件。4.2加載系統(tǒng) 4.2.1高壓釜需配備疲勞機加載系統(tǒng)，推薦試驗裝置配備壓力平衡系統(tǒng)，平衡釜內(nèi)

6、水壓對拉伸桿施加的壓力。4.2.2在高溫高壓水環(huán)境下能夠?qū)崿F(xiàn)力控制、應變控制或者位移控制加載模式。4.2.3能夠加載三角波、正弦波和梯形波等波形。 4.2.4圖1給出了推薦的加載系統(tǒng)示意圖。圖1典型的高溫高壓循環(huán)水腐蝕疲勞試驗系統(tǒng)4.3加熱及控溫裝置4.3.1宜采用電加熱方式加熱。4.3.2加熱裝置及控溫儀器應具有滿足試驗要求的升溫速度，在試驗溫度下能長期保溫，并且穩(wěn)定、可 靠、操作方便。盡量保持高壓釜內(nèi)溫度均勻，并確保高壓釜內(nèi)熱電偶在試樣附近，實時監(jiān)測試樣處試驗 溫度。4.3.3控溫精度±1 °C。4.4應變監(jiān)測系統(tǒng)在疲勞試驗過程中，可采用線性可變差動變壓位移傳感器或應變

7、引伸計等方法原位實時監(jiān)測試樣 在高溫高壓水中的應變，測量精度一般應優(yōu)于±5 /urn或者±5 %。#學兔兔標準下載T/CNS 420185試樣制備和要求5.1試樣的材料要求試樣材料為核電廠用金屬材料，包括碳鋼、低合金鋼、奧氏體不銹鋼、鎳基合金、鋯合金等，取樣應具 有代表性。5.2試樣的形狀尺寸5.2.1圓形橫截面試樣通常試樣可采取如圖2所示的在平行部分與夾持端具有切向過渡圓弧的圓形橫截面試樣。試樣形 狀尺寸、同軸度等要求按GB/T 152482008的規(guī)定執(zhí)行。5.2.2矩形橫截面試樣如受原材料形狀、尺寸大小限制，不能制成圓形橫截面試樣，亦可采用平行部分與夾持端具有切向 過

8、渡圓弧的矩形橫截面試樣，如圖3所示。試樣形狀尺寸、同軸度等要求按GB/T 15248-2008的規(guī)定 執(zhí)行。5.3試樣夾持方式5.3.1圓形橫截面試樣，推薦夾持方式如圖4所示，由末端臺階型圓形橫截面試樣、一對半圓形頸圈、 底座、樣品臺、螺栓組成。半圓形頸圈、試樣、底座通過臺階方式配合安裝，通過螺栓與樣品臺連接，在疲 勞過程中能夠穩(wěn)定對疲勞試樣施加載荷。其他能夠保證試樣對中性、對試樣提供穩(wěn)定夾持力的夾持方 式亦可采用。5.3.2矩形橫截面試樣，推薦夾持方式如圖5所示，由疲勞試樣、夾塊、歐姆夾、底座、樣品臺、螺栓組 成。利用歐姆夾與夾塊夾持疲勞試樣，夾塊、底座通過臺階方式配合安裝，通過螺栓與樣品臺

9、連接，在疲 勞過程中能夠穩(wěn)定對疲勞試樣施加載荷。其他能夠保證試樣對中性、對試樣提供穩(wěn)定夾持力的夾持方 式亦可采用。5.4試樣加工試樣的取樣部位和取向應按有關(guān)標準或雙方協(xié)議，所采用的機加工在試樣表面產(chǎn)生的殘余應力和 加工硬化應盡可能小，宜按GB/T 152482008的規(guī)定執(zhí)行。5.5表面粗糙度宜采用水磨砂紙或紗布沿試樣縱向進行機械拋光，標距段表面粗糙度一般應優(yōu)于0.8亦可根據(jù)需求決定。5.6試樣保存疲勞試樣應妥善保存，尤其是易氧化的低合金鋼、碳鋼等材料，需在干燥皿中密封保存，防止試樣氧 化、受雜質(zhì)污染。7說明：d標距段直徑;r過渡段圓弧半徑。圖2圓形橫截面試樣swtc+1說明：T厚度；L標距段

10、長度；H標距段寬度;W夾持段寬度。矩形橫截面試樣說明：1 疲勞試樣；2 半圓形頸圈；3 底座；4 樣品臺；5 螺栓。圖4圓形橫截面試樣夾持方式說明：1 疲勞試樣;2 夾塊；3 歐姆夾；4 底座;5 樣品臺;6 螺栓。圖5矩形橫截面試樣夾持方式6試驗條件和步驟6.1溶液配制6.1.1采用電導率小于1 MS/cm的去離子水或蒸餾水配制試驗溶液。6.1.2根據(jù)試驗要求，采用分析純級試劑配制試驗溶液。6.2試驗條件6.2.1對于動態(tài)循環(huán)高壓釜，溶液應充滿高壓釜腔，壓力高于該溶液飽和蒸汽壓。6.2.2調(diào)節(jié)高壓泵選擇合適的溶液流量，應確保高壓釜內(nèi)溶液在1 h內(nèi)至少更換1次。6.2.3 升溫速度宜控制在70

11、 °C/h100 °C/h。6.3試驗步驟6.3.1將試樣安裝在夾具上，安裝后同軸度良好，確保疲勞試驗數(shù)據(jù)有效。6.3.2在試樣上安裝原位應變監(jiān)測系統(tǒng)。6.3.3高壓釜擰緊后，將試驗溶液配制好后注人儲水罐及高壓釜中，并按具體試驗要求調(diào)節(jié)壓力、流 量、溶解氧。6.3.4確認測溫、測壓及安全保護裝置均處于正常狀態(tài)后，開始加壓并達到壓力設(shè)定值，確認無泄漏后 開始加熱升溫。6.3.5當溫度、壓力穩(wěn)定到試驗目標值后，設(shè)置疲勞機試驗位移、應變速率、加載波形等參數(shù)，開始疲勞 試驗。6.3.6當峰值拉應力到達穩(wěn)定值后，設(shè)置試驗終止條件，如峰值拉應力下降至最大峰值拉應力的75% 時停止。6.

12、3.7試驗結(jié)束后，將試樣取出，妥善保存。7數(shù)據(jù)處理7.1試驗結(jié)果有效性判定疲勞裂紋萌生于疲勞試樣標距段內(nèi)，且疲勞試樣無明顯彎扭變形，則試驗結(jié)果有效。7.2數(shù)據(jù)處理方法和要求7.2.1記錄試樣標距段表面疲勞裂紋宏觀形貌。7.2.2選擇典型的疲勞試樣，分析疲勞斷口形貌，宜在液氮中冷卻后敲斷，利用掃描電鏡記錄疲勞裂紋 源、裂紋擴展區(qū)等的形貌特征。7.2.3需要時，將獲得的疲勞數(shù)據(jù)匯總，繪制相應的應變-疲勞壽命（S-N）曲線。一般獲得S-N曲線需 要4個以上不同應變幅條件下的疲勞壽命，且每個實驗至少重復3次。典型的高溫高壓循環(huán)水腐蝕疲 勞S-N曲線如圖6所示。8質(zhì)量保證8.1試驗人員要求高溫高壓水腐蝕

13、疲勞試驗人員應經(jīng)過培訓且滿足以下要求：a）能熟練操作疲勞機，設(shè)置預定的應變幅、應變速率、應變比和加載波形；b）能熟練操作高壓釜的升降，高壓釜硬密封擰緊程序；c）能熟練操作高溫高壓循環(huán)水系統(tǒng)，如溶解氧、電導率等水化學參數(shù)設(shè)置、高壓釜內(nèi)壓力調(diào)節(jié)、高 壓釜內(nèi)溫度調(diào)節(jié)等的控制；d）能熟練安裝、卸裝疲勞試樣。8.2試驗系統(tǒng)校準要求按照相關(guān)規(guī)定定期對疲勞機力傳感器、位移傳感器、高精度線性可變差動變壓位移傳感器、高壓釜 熱電偶、預熱器熱電偶、溶解氧探頭、壓力傳感器、pH探頭等進行計量標定，并在有效期內(nèi)使用。 9試驗報告試驗報告應包括但不限于以下內(nèi)容:a）本標準編號；b）材料名稱、熱處理狀態(tài)和拉伸性能；c）試

14、樣形狀尺寸、表面狀態(tài)、取樣位置、取樣方向；d）試驗參數(shù)，如：應變幅值、應變速率、應變比、加載波形、溫度、壓力、溶解氧濃度;e）試驗結(jié)果，包括疲勞數(shù)據(jù)、疲勞裂紋形貌、斷口形貌等；D 試驗異常記錄；g）試驗人員和日期。0. 050. 1501 021 031 04IO6106疲勞壽命i %/ffi制垣圖6典型的高溫高壓循環(huán)水腐蝕疲勞S-N曲線ICS 77.040.10 H 22Association Standard of Chinese Nuclear SocietyT/CNS 42018Test method for corrosion fatigue in high temperature

15、pressurized water of metallic materials for nuclearpower plants核電廠金屬材料高溫高壓水中腐蝕疲 勞試驗方法(English Translation)Issue date：2019-05-27Implementation date：2019-09-01Issued by Chinese Nuclear Society9T/CNS 42018ForewordChinese Nuclear Society is in charge of this English translation. In case of any doubt abo

16、ut the contents of English translation,the Chinese original shall be considered authoritative.This standard is drafted in accordance with the rules given in the GB/T 1.12009 Directives forstandardization Part 1 : Structure and drafting of standards.This standard was proposed by Chinese Nuclear Socie

17、ty.This standard was prepared by Institute for Standardization of Nuclear Industry.ioT/CNS 42018Test method for corrosion fatigue in high temperature pressurized water of metallic materials for nuclear power plants1 ScopeThis standard specifies the test method and related technical requirements for

18、corrosion fatigue test of metallic materials specimen in high temperature high pressure water, including strain control and stroke control modes.This standard is applicable to corrosion fatigue test for specimens with circular and rectangular cross section of a certain gauge length in water below 36

19、0 °C，including strain control and stroke control modes. Components and other special shape specimens may be tested according to this standard.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated reference, only the edition ci

20、ted applies. For undated reference, the latest edition of the reference document (including any amendments) applies.GB/T 150.42011, Pressure vesselsPart 4： Fabrication , inspection and testing, and acceptance GB/T 30752008, Metallic materialsFatigue testingAxial-force-control led methodGB/T 15248200

21、8，The test method for axial loading cons tan t-ampli tude low-cycle fatigue of metallic materialsGB/T 20120.12006, Corrosion of metals and alloysCorrosion fatigue testingPart 1: Cycles to failure testing3 Terms and definitionsFor the purposes of this document, the terms and definitions given in GB/T

22、 152482008, GB/T 20120.12006 and GB/T 30752008 and the following apply.3.1fatigue life the number of cycles for tensile stress to drop 25% from its peak value3.2 strain rate two times of strain range multiplied by frequency4 Apparatus4.1 Autoclave4.1.1 The body and cover of an autoclave shall be mad

23、e of corrosion-resistant alloys such as stainless steel and nickel-based alloy. In general, the autoclave body should be integral, and welding is allowed under special circumstances but non-destructive test is required.4.1.2 The contact surface between autoclave body and its cover shall be sealed, a

24、s well as the holes through the cover. No leakage is permitted during the test.4.1.3 It can simulate the typical light water reactor environment and run steadily for a long time in high temperature water below 360 °C and 20 MPa.4.1.4 Safety protection devices are required for the autoclave, and

25、 they shall be inspected regularly.4.1.5 Non-destructive tests for autoclave body，cover and other temperature and pressure bearing components are required as specified in GB/T 150.42011，and the autoclave can only be used if it is acceptable.4.1.6 The specimen holder in the autoclave is recommended t

26、o be made of high-temperature-resistant and corrosion-resistant materials such as stainless steel and nickel-based alloy.4.1.7 Figure 1 shows a schematic diagram of a recommended high temperature high pressure water circulation system and an autoclave structure.4.1.8 Cooling water circulation loop i

27、s required for the autoclave to protect the displacement sensor, force sensor, seal and other devices that are not high temperature resistant.4.2 Loading system4.2.1 The autoclave needs to be equipped with a fatigue machine. It is recommended that the experimental system is equipped with a pressure

28、balance device to keep the specimen from additional stress.4.2.2 The fatigue machine can provide load control, strain control or stroke control mode in high temperature high pressure water environment.4.2.3 The fatigue machine can provide loading of triangular wave, sine wave, trapezoid wave, etc.4.

29、2.4 Figure 1 shows a schematic diagram of a recommended loading system.4.3 Heating and temperature control device4.3.1 Electrical heating is recommended.4.3.2 Heating and temperature control device should have a suitable heating rate to meet the test requirement, keep the test temperature for long p

30、eriod, and be stable, reliable and easy to operate. The temperature in the autoclave should be distributed homogeneously. The thermal couple should be placed near the specimen to monitor the specimen temperature instantaneously.4.3.3 The temperature accuracy should be controlled within ± 1 

31、6;C.4.4 Strain monitoring systemThe strain of specimen shall be monitored during fatigue test in high temperature high pressure water. It is reconmmended to use linear variable differential transformer (LVDT) sensor or strain extensometer to monitor the strain. The measurement accuracy shall be bett

32、er than 土5 um or 土5%.DOConpHMixingpumpStabilizerexchangeresin iHigh pressure pump3aFlowmeterexchangerFatigue machineFigure 1Typical high temperature high pressure circulating water fatigue test systemHeatingfurnance Autoclave SpecimenStrain monitorin > systemBack pressure regulatorSafetyvalvePre-

33、heater5 Specimen preparation and requirements5.1 Material requirements for specimensThe specimens are metallic materials used in nuclear power plant, including carbon steel，low alloy steel, austenitic stainless steel, nickel based alloy and zirconium alloy. Sampling of the material should be represe

34、ntative.5.2 Specimen shape and size5.2.1 Specimen with circular cross sectionFigure 2 shows a recommended specimen with circular cross section and uniform gage. The specimen size and axiality shall be in accordance with GB/T 15248 2008.5.2.2 Specimen with rectangular cross sectionIt is acceptable to

35、 use specimens with rectangular cross-section where the transitional parts between the parallel sections and the clamped section are arc (See Figure 3). The specimen shape, size and axiality shall be in accordance with GB/T 15248 2008 standard.5.3 Fixtures5.3.1 Figure 4 shows a typical clamping meth

36、od for specimen with circular cross section. The fixture consists of a semicylindrical split collar, a body of fixture, bolts and a specimen holder. The semicylindrical split collar, body of fixture and specimen with circular cross section shall be assembled using step mode and connected to the spec

37、imen holder with bolts. The fixture can stably clamp the specimens during the fatigue test. Other clamping techniques that can provide stable clamping force and good axiality are also acceptable.5.3.2 Figure 5 shows a typical clamping method for specimen with rectangular cross section. The fixture c

38、onsists of a cylindrical chuck，an ohm chuck，body of fixture, bolts and a specimen holder. The specimen with rectangular cross section shall be clamped using the cylindrical chuck and the ohm chuck, and connected to the specimen holder with bolts. The fixture should be able to clamp the specimens sta

39、bly during the fatigue test. Other clamping techniques that can provide stable clamping force and good axiality are also acceptable.5.4 Specimen processingThe sampling location and orientation shall be in accordance with relevant standards or mutual agreement. The residual stress and work hardening

40、of the machined surface should be as little as possible. It is recommended to be in accordance with GB/T 15248 2008.5.5 Surface roughnessIt is recommended to use waterproof abrasive paper or polishing cloth to mechanically polish the specimen surface in axis direction. The surface roughness of gauge

41、 section shall be lower than 0.8 um or in accordance with the requirement.5.6 Specimen storageTo prevent specimens from being oxidized or contaminated, they should be be stored in a suitable environment, such as in a desiccator, especially for carbon steel and low alloy steel.17Keyd the diameter of

42、gauge sectionr the radius of transition arcL=3T±T/2Figure 2Specimen with circular cross sectionKeythe thicknessL the length of the gauge section H the width of the gauge sectionW the width of the clamping sectionFigure 3Specimen with rectangular cross sectionNOTE： 1 specimen with circular cross

43、 section； 2 cylindrical split collar； 3 body of fixture； 4 specimen holder； 5 bolts.Figure 4Schematic of clamping method for specimen with circular cross section4 body of fixture； 5 specimenNOTE： 1 specimen with rectangular cross section； 2 cylindrical chuck； 3 ohm chuck；holder； 6 bolts.Figure 5Sche

44、matic of clamping method for specimen with rectangular cross section6 Test condition and procedure6.1 Solution preparation6.1.1 Deionized or distilled water with a conductivity less than 1 pS/cm shall be used to prepare the test solution.6.1.2 Analytical reagents are recommended to prepare the solut

45、ion in accordance with the test requirement.6.2 Test condition6.2.1 For dynamic circulation autoclave, its chamber shall be filled with solution. The applied pressure shall be higher than its saturated vapor pressure.6.2.2 Adjust high pressure pump to get the appropriate flow to ensure the solution

46、in the autoclave be recycled at least once per hour.6.2.3 The heating rate is recommended as 70 oC/h100 °C /h.6.3 Testing procedure6.3.1 The specimen shall be installed with axiality good enough to ensure the validity of fatigue test data.6.3.2 A strain monitoring device shall be installed on t

47、he specimen.6.3.3 The test solution is pumped into the autoclave after the autoclave is sealed. Pressure, flow rate and dissolved oxygen concentration shall be adjusted according to test requirement.6.3.4 After checking all the temperature and pressure measuring and protection devices, raise the pre

48、ssure to the set value, and then start heating after confirming there is no leakage.6.3.5 After the temperature and pressure are stable at the target value, set test stroke or strain amplitude, strain rate，loading wave on the fatigue machine, and then start fatigue test.6.3.6 After the tensile stres

49、s is stable, set the test termination condition, for example, the tensile stress drops to 75% of the peak tensile stress.6.3.7 After the fatigue test is finished, remove and store the specimen.7 Test data processing7.1 Validity of test resultsThe test results are valid only if the fatigue crack init

50、iates at the gauge region and the fatigue specimen has no obvious bending and torsion.7.2 Test data processing7.2.1 The macroscopic morphology of fatigue crack on specimen surface shall be recorded.7.2.2 A typical fatigue specimen shall be chosen and its fatigue fracture surface morphology shall be

51、analyzed. It is recommended to break apart the tested specimen in liquid nitrogen. The morphology characteristics of fatigue crack, including crack intiation and propagation region, shall be recorded by scanning electron microscope.7.2.3 If necesarry, the fatigue data shall be fitted to obtain the strain-fatigue life (S-N) curve. Generally, fatigue data shall be obtained at least 4 different strain amplitue levels and each experiment shall be repeated at least 3 times. Figure 6 shows a typical S-N curve for metallic mat