JPH0142381B2 - - Google Patents
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- Publication number
- JPH0142381B2 JPH0142381B2 JP57070437A JP7043782A JPH0142381B2 JP H0142381 B2 JPH0142381 B2 JP H0142381B2 JP 57070437 A JP57070437 A JP 57070437A JP 7043782 A JP7043782 A JP 7043782A JP H0142381 B2 JPH0142381 B2 JP H0142381B2
- Authority
- JP
- Japan
- Prior art keywords
- creep
- consumption rate
- fatigue
- time
- stress
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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- 238000000034 method Methods 0.000 claims description 39
- 239000007769 metal material Substances 0.000 claims description 20
- 238000010586 diagram Methods 0.000 claims description 13
- 238000012360 testing method Methods 0.000 claims description 3
- 125000004122 cyclic group Chemical group 0.000 claims 1
- 238000009661 fatigue test Methods 0.000 claims 1
- 239000000463 material Substances 0.000 description 12
- 150000001247 metal acetylides Chemical class 0.000 description 9
- 238000007689 inspection Methods 0.000 description 6
- 230000002776 aggregation Effects 0.000 description 5
- 238000005054 agglomeration Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000000737 periodic effect Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000007542 hardness measurement Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000004220 aggregation Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000012549 training Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/20—Metals
- G01N33/204—Structure thereof, e.g. crystal structure
- G01N33/2045—Defects
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Description
【発明の詳細な説明】
本発明は金属材料の寿命予知方法に関する。特
に、硬さの測定と電気抵抗法とを併用して、高温
環境下で荷重を受ける金属材料の寿命を予知する
方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for predicting the lifespan of metal materials. In particular, the present invention relates to a method of predicting the lifespan of metal materials that are subjected to loads in high-temperature environments by using both hardness measurements and electrical resistance methods.
従来、室温において疲労させた材料の損傷率を
硬さの測定によつて診断する方法は知られてい
る。しかし、高温環境下で使用される蒸気タービ
ンや原子力発電プラントの部材の如き金属材料に
ついては寿命予知方法はない。特に、このような
高温環境下での金属材料は、疲労のみならずクリ
ープも受ける。従来、このようにクリープと疲労
を一緒に受ける場合の寿命予知方法はなかつた。 Conventionally, methods are known for diagnosing the damage rate of materials fatigued at room temperature by measuring hardness. However, there is no method for predicting the lifespan of metal materials used in high-temperature environments, such as steam turbines and members of nuclear power plants. In particular, metal materials in such high-temperature environments are subject to not only fatigue but also creep. Conventionally, there was no method for predicting the lifespan when creep and fatigue are experienced together.
上記事情に鑑み、本発明者らは金属材料の破壊
過程が結晶変形並びに炭化物の凝集・粗大化に基
くものであり、ビツカース硬さは結晶変形に敏感
であり、一方電気抵抗法は炭化物の凝集・粗大化
並びにマトリクス成分の変化に敏感である事に着
目し、クリープ・疲労相互作用を受けた金属材料
の構造変化を硬さの測定並びに電気抵抗法により
評価する事により高温環境下での金属材料の余寿
命を予知する方法を提供せんとして本発明に到達
したのである。 In view of the above circumstances, the present inventors found that the fracture process of metallic materials is based on crystal deformation and agglomeration and coarsening of carbides, and that the Vickers hardness is sensitive to crystal deformation, while the electrical resistance method is based on the aggregation and coarsening of carbides.・Focusing on the fact that metal materials are sensitive to coarsening and changes in matrix components, we evaluate the structural changes of metal materials subjected to creep and fatigue interactions using hardness measurements and electrical resistance methods. The present invention was achieved with the aim of providing a method for predicting the remaining life of materials.
本発明の目的は、高温環境下で荷重を受ける金
属材料の寿命予知方法を提供するにある。 An object of the present invention is to provide a method for predicting the life of a metal material that is subjected to a load in a high-temperature environment.
本発明は、高温環境下で荷重を受ける金属材料
の寿命を予知する方法において、該金属材料のビ
ツカース硬さと電気抵抗とを求める工程、既知の
ビツカース硬さと応力繰返し疲労試験による疲労
破壊回数に対する応力繰返し数の比によつて算出
される疲労寿命消費率との関係に基づいて前記求
められたビツカース硬さに対応する疲労寿命消費
率を推定する工程、既知の電気抵抗値とクリープ
試験によるクリープ変形量との関係に基づいて前
記求められた電気抵抗値に対応するクリープ変形
量を推定する工程、既知の応力とクリープ変形量
及びクリープ時間との関係を示す線図に基づいて
前記推定されたクリープ変形量から前記金属材料
の使用温度及び時間に対応する応力を推定する工
程、既知の電気抵抗値とクリープ試験によるクリ
ープ破断時間に対するクリープ時間の比によつて
算出されるクリープ寿命消費率との関係に基づい
て前記推定された応力と前記使用温度及び時間に
対応するクリープ寿命消費率を推定する工程、既
知の疲労寿命消費率とクリープ寿命消費率との関
係に基づいて表わされる被害曲線図に前記推定さ
れる疲労寿命消費率とクリープ寿命消費率をプロ
ツトし、該プロツトした点と前記被害曲線との関
係に基づいて前記金属材料の余寿命を推定する工
程を含むことを特徴とする金属材料の寿命予知方
法にある。 The present invention relates to a method for predicting the life of a metal material that is subjected to a load in a high-temperature environment. A step of estimating the fatigue life consumption rate corresponding to the determined Vickers hardness based on the relationship with the fatigue life consumption rate calculated by the ratio of the number of repetitions, creep deformation by a known electrical resistance value and a creep test a step of estimating the amount of creep deformation corresponding to the determined electrical resistance value based on the relationship between the estimated creep amount and the amount of creep deformation based on a diagram showing the relationship between the known stress, the amount of creep deformation, and the creep time A process of estimating the stress corresponding to the operating temperature and time of the metal material from the amount of deformation, and the relationship between the known electrical resistance value and the creep life consumption rate calculated from the ratio of the creep time to the creep rupture time by a creep test. estimating the creep life consumption rate corresponding to the estimated stress and the operating temperature and time based on the damage curve diagram expressed based on the relationship between the known fatigue life consumption rate and the creep life consumption rate. A method of manufacturing a metal material, comprising the step of plotting an estimated fatigue life consumption rate and a creep life consumption rate, and estimating the remaining life of the metal material based on the relationship between the plotted points and the damage curve. It is in the life prediction method.
本発明は、高温環境下で荷重を受ける金属材料
のビツカース硬さと電気抵抗とを測定して得たパ
ラメータを用いて寿命を予知するものである。 The present invention predicts the life of a metal material using parameters obtained by measuring the Vickers hardness and electrical resistance of a metal material that is subjected to a load in a high-temperature environment.
この場合、ビツカース硬さを測定して疲労被害
を検出し、電気抵抗を用いてクリープ被害を検出
する事によつて、疲労とクリープとが重畳した場
合の寿命を予知できる。更に、既知のビツカース
硬さと疲労寿命消費率との関係に基いて疲労被害
を検出し、一方既知の電気抵抗とクリープ変形量
との関係に基いてクリープ変形量を推定し、該推
定クリープ変形量から既知の応力とクリープとの
関係を示すクリープ曲線を用いて加えられてい
た。応力を推定すると共に、クリープ寿命消費率
を推定し、前記ビツカース硬さから推定した疲労
寿命消費率と前記電気抵抗から推定したクリープ
寿命消費率とを既知の疲労とクリープとが重畳し
た場合の被害曲線に適合させる事によつて損傷を
検出し、これにより余寿命を推定するものであ
る。 In this case, by measuring Vickers hardness to detect fatigue damage and using electrical resistance to detect creep damage, it is possible to predict the life in the case where fatigue and creep overlap. Furthermore, fatigue damage is detected based on the relationship between the known Vickers hardness and fatigue life consumption rate, and the amount of creep deformation is estimated based on the relationship between the known electrical resistance and the amount of creep deformation. It was applied using a creep curve that shows the relationship between stress and creep, which is known from . In addition to estimating the stress, the creep life consumption rate is estimated, and the fatigue life consumption rate estimated from the above-mentioned Bitkers hardness and the creep life consumption rate estimated from the above-mentioned electrical resistance are calculated to calculate the damage caused when known fatigue and creep are superimposed. Damage is detected by fitting the curve, and the remaining life is estimated based on this.
以下、本発明につき具体的に説明する。 The present invention will be specifically explained below.
初めに疲労被害の検出法について述べる。ビツ
カース硬さは結晶内部の転位密度や微視的格子歪
と関係しており焼なまし状態では極めて小さく、
塑性変形を受けてそれらの格子欠陥が増大すると
増す。疲労変形の場合も同様で、疲労過程中のビ
ツカース硬さは例えば焼なまし材の場合には第１
図の様に増大する。図には応力の大きさに応じて
３段階で示したが、応力振巾が高い順（σ1＞σ2＞
σ3）で増加速度も早くなつている。しかしビツカ
ース硬さを破断繰返し数Nfに対する応力繰返し
数Ｎの比Ｎ／Nfとの相関で見てみると、第２図
の如く斜線を施す程度のばらつきはあるが、ほぼ
１本の線で表わす事ができる。 First, we will describe the method for detecting fatigue damage. Vickers hardness is related to the dislocation density and microscopic lattice strain inside the crystal, and is extremely small in the annealed state.
It increases as those lattice defects increase due to plastic deformation. The same is true for fatigue deformation; the Vickers hardness during the fatigue process is, for example, the first in the case of annealed material.
It increases as shown in the figure. The diagram shows three levels according to the magnitude of stress, but the order of stress amplitude (σ 1 > σ 2 >
σ 3 ), the rate of increase is also faster. However, when we look at the Vickers hardness in relation to the ratio N/Nf of the number of stress cycles to the number of cycles to fracture Nf, it can be expressed as almost a single line, although there is some variation in the degree of diagonal lines as shown in Figure 2. I can do things.
一方、予加工材つまり予め塑性変形を加えて硬
さを増大させておいた材料を疲労させるビツカー
ス硬さは第３図の如く上記Ｎ／Nfに対して単調
に減少する。従つて、種々の熱処理条件や加工条
件によつて第２，３図の如きビツカース硬さ変化
のマスター曲線を作成しておけば応力繰返し数Ｎ
を記録しておいてビツカース硬さを測定する事に
よつて余寿命Nrを推定できる。或いは、測定ま
での繰返し数が不明でもビツカース硬さを２回計
測すればその間の繰返し数もわかるので、これに
よつても余寿命を推定できる。 On the other hand, the Vickers hardness, which causes fatigue in a preformed material, that is, a material whose hardness has been increased by plastic deformation, decreases monotonically with respect to N/Nf, as shown in FIG. Therefore, by creating master curves of Vickers hardness changes as shown in Figures 2 and 3 under various heat treatment conditions and processing conditions, the number of stress repetitions N can be reduced.
By recording and measuring the Vickers hardness, the remaining life Nr can be estimated. Alternatively, even if the number of repetitions until the measurement is unknown, if the Vickers hardness is measured twice, the number of repetitions in between can be known, and the remaining life can also be estimated from this.
第４図にはこの様な手法に基く余寿命推定法を
示す。図示の例は焼なまし材でのマスター曲線を
用いたものである。運転開始後繰返し数N1がわ
かつている時点でのビツカース硬さがHv1であれ
ば、ビツカース硬さ変化のマスター曲線によりそ
の時の疲労寿命消費率φf1（＝N1／Nf）がわかる。
よつて、余寿命Nr＝Nf−N1は
Nr＝Nf１−φf1／φf1 …(1)
で与えられる。繰返し数N1が不明な場合でもビ
ツカース硬さを２回計測して余寿命を知る事がで
きる。つまり、ビツカース硬さHv1の時点の後、
更に繰返し数N2＝N1＋Ｎまで疲労させて該時点
のビツカース硬さHv2を測定すれば、その時の
φf2が求まり、且つその間の繰返し数はＮである
事がわかつているので、余寿命Nr′は次式で与え
られる。 FIG. 4 shows a remaining life estimation method based on such a method. The illustrated example uses a master curve for annealed material. If the Vickers hardness is Hv 1 at the time when the number of repetitions N 1 after the start of operation is known, the fatigue life consumption rate φf 1 (=N 1 /Nf) at that time can be determined from the master curve of Vickers hardness changes.
Therefore, the remaining life Nr=Nf−N 1 is given by Nr=Nf1−φf 1 /φf 1 (1). Even if the number of repetitions N1 is unknown, the remaining life can be determined by measuring the Bitkers hardness twice. That is, after the point of Bitkers hardness Hv 1 ,
If we further fatigue the specimen up to the number of repetitions N 2 = N 1 +N and measure the Vickers hardness Hv 2 at that point, we can find φf 2 at that time, and since we know that the number of repetitions during that time is N, we can The life Nr′ is given by the following formula.
Nr′＝Ｎ１−φf2／φf2−φf1 …(2)
第２，３図の如きマスター曲線を腐食環境、高
温環境などの実機環境下で作成しておけば該環境
下での構造部材の寿命も上記と全く同様にして予
知できる。 Nr' = N1 - φf 2 / φf 2 - φf 1 ...(2) If master curves such as those shown in Figures 2 and 3 are created in an actual machine environment such as a corrosive environment or high temperature environment, structural members can be used in such environments. The lifespan of can also be predicted in exactly the same way as above.
次に、クリープに基づく損傷による寿命の予知
方法について述べる。 Next, a method for predicting service life due to creep-based damage will be described.
クリープ中の電気抵抗は焼なまし材の場合には
第５図の様に低下する。図には応力の大きさに応
じて３段階で示したが、負荷応力が高い順（σ1＞
σ2＞σ3）で減少速度も早くなる。しかし、電気抵
抗をクリープによつて破断に至るまでの時間tfに
対するクリープ時間ｔの比ｔ／tfとの相関でみる
と、第６図に示した様に斜線を施して示すばらつ
きの範囲内でほぼ１本の線で表わす事ができる。 The electrical resistance during creep decreases as shown in Figure 5 in the case of annealed materials. The figure shows three levels according to the magnitude of stress, but the order of load stress (σ 1 >
σ 2 >σ 3 ), the rate of decrease also becomes faster. However, when looking at the correlation between the electrical resistance and the ratio t/t f of the creep time t to the time t f until rupture due to creep, the range of dispersion shown by diagonal lines as shown in Figure 6. It can be represented by almost one line within the range.
上記に示した様に使用温度で測定される抵抗率
変化は炭化物反応に依存している。したがつて電
気抵抗法は炭化物反応及びそれに伴なう機械的性
質を検出するのに有効である。クリープ伸びの小
さい第１〜２次クリープ領域内では炭化物反応は
それほど促進されないが、第３次クリープ域にお
いては十分析出が促進される。それは界面エネル
ギーを減少させるため小さな炭化物がより大きな
炭化物に食われる凝集・粗大化現象やM3C→
M23C6の様な炭化物の組成変化現象が起る事を意
味している。 As indicated above, the resistivity change measured at service temperature is dependent on carbide reactions. Therefore, the electrical resistance method is effective in detecting carbide reactions and the mechanical properties associated with them. In the first and second creep regions where creep elongation is small, the carbide reaction is not promoted so much, but in the tertiary creep region, precipitation is promoted to a large extent. This is due to the agglomeration/coarsening phenomenon in which small carbides are eaten by larger carbides and M 3 C→
This means that a composition change phenomenon of carbides such as M 23 C 6 occurs.
炭化物の分布状態や形状は鋼の強度や靭性を決
める大きな要因であつて、使用中における炭化物
の形状変化に伴なう材料の機械的性質の劣化が電
気抵抗法によつて診断できる。 The distribution state and shape of carbides are major factors that determine the strength and toughness of steel, and deterioration of the mechanical properties of the material due to changes in the shape of carbides during use can be diagnosed using the electrical resistance method.
炭化物の凝集・粗大化とクリープ変形量との間
には第７図に示す様な関係がある。この場合クリ
ープ変形量は加熱温度、時間、負荷応力がそれぞ
れ高く、或いは長くなれば殆んど大きくなるもの
である。従つて、電気抵抗を測定する事によつて
炭化物反応が求められるわけであつて、これに基
き、クリープのマスター曲線を予め作成しておい
た上でクリープ時間ｔを記録し、改めて電気抵抗
を測定する事によつて余寿命trを推定できる。ク
リープ時間ｔが不明な場合には２回電気抵抗を測
定し、両測定間の時間を知つておけば余寿命trを
推定できる。 There is a relationship as shown in FIG. 7 between the agglomeration and coarsening of carbides and the amount of creep deformation. In this case, the amount of creep deformation increases as the heating temperature, time, and load stress become higher or longer. Therefore, the carbide reaction can be determined by measuring the electrical resistance. Based on this, a master creep curve is created in advance, the creep time t is recorded, and the electrical resistance is measured again. By measuring, the remaining life t r can be estimated. If the creep time t is unknown, the electrical resistance is measured twice and the remaining life t r can be estimated by knowing the time between both measurements.
この手法に従う余寿命推定法を第８図に示す。
運転開始後t1時間での電気抵抗がP1であれば、電
気抵抗とクリープ時間比の関係のマスター曲線ａ
からクリープ時間比が求まる。このクリープ時間
比を予め得ておいて実機と同じ温度下で得られた
種々の応力における電気抵抗を表わすクリープ曲
線ｂに適用し、この電気抵抗P1とクリープ時間t1
との交点から応力を推定する。この様にして得ら
れた応力がσ2であれば、余寿命trは、tr＝tf−t1で
与えられる。 The remaining life estimation method according to this method is shown in FIG.
If the electrical resistance at t 1 hour after the start of operation is P 1 , then the master curve a of the relationship between electrical resistance and creep time ratio is
The creep time ratio can be found from Obtain this creep time ratio in advance and apply it to the creep curve b representing the electrical resistance at various stresses obtained under the same temperature as the actual machine, and calculate this electrical resistance P 1 and creep time t 1
Estimate the stress from the intersection with If the stress obtained in this way is σ 2 , the remaining life t r is given by t r =t f −t 1 .
運転時間t1が不明の場合には上記の様な測定の
後ｔ時間使用後に同様な測定を行なう。ｔ時間後
の電気抵抗がP2で、クリープ時間比がt2／tfと求
まつた場合、第８図のグラフｂに破線で示した曲
線の様に電気抵抗の変化傾向が一致するクリープ
曲線を推定して、電気抵抗がP2の時の運転時間t2
と、応力σ1とσ2の内挿から運転中の応力σ′を推定
し、これによつて余寿命tr′をtr′＝tf−t2にて求め
る事ができる。 If the operating time t1 is unknown, the same measurement is performed after the above-mentioned measurement and after t hours of use. If the electrical resistance after t time is P 2 and the creep time ratio is found to be t 2 /t f , then the creep pattern in which the change tendency of the electrical resistance matches the curve shown by the broken line in graph b in Fig. 8 is obtained. Estimate the curve and find the operating time t 2 when the electrical resistance is P 2
Then, the stress σ' during operation can be estimated from the interpolation of the stresses σ 1 and σ 2 , and the remaining life t r ′ can be calculated as t r ′=t f −t 2 .
以上、高温疲労とクリープとの場合を各々につ
いて説明したが、次に高温疲労とクリープとが重
畳した場合の余寿命診断について説明する。この
時の手順は第９図に示す。クリープ被害は電気抵
抗により検出し、疲労被害は硬さの測定により検
出するものとする。クリープ被害については前述
した通りまず第９図ａのマスター曲線によりクリ
ープ時間比を求め、このクリープ時間比に基き同
図ｂより余寿命trを求め、これによつてクリープ
寿命消費率φc＝ｔ／tfを求める。一方、ビツカー
ス硬さHvにより同図ｃに示すマスター曲線を用
いて疲労被害に対する余寿命Nrを求める。これ
によつて寿命消費率φf＝Ｎ／Nfを求める双方の
寿命消費率φc，φfを得た段階で予め実験室で求
めておいた疲労とクリープとの重畳下における被
害曲線に両方の値を適用させ、全体の被害を検出
して余寿命を推定する。第９図ｄがその被害曲線
を示すと共に両方の寿命消費率φc，φfの適用を
示す。 The cases of high-temperature fatigue and creep have been explained above, and next, the remaining life diagnosis when high-temperature fatigue and creep overlap will be explained. The procedure at this time is shown in FIG. Creep damage shall be detected by electrical resistance, and fatigue damage shall be detected by hardness measurement. As for creep damage, as mentioned above, first find the creep time ratio using the master curve in Figure 9a, and based on this creep time ratio, find the remaining life t r from Figure 9b, and from this, the creep life consumption rate φc = t /t Find f . On the other hand, the remaining life Nr against fatigue damage is determined using the master curve shown in c in the figure based on the Vickers hardness Hv. By doing this, the life consumption rate φf = N/Nf is calculated. At the stage where both life consumption rates φc and φf are obtained, both values are added to the damage curve under the superimposition of fatigue and creep, which was previously determined in the laboratory. applied to detect overall damage and estimate remaining life. Figure 9d shows the damage curve and the application of both life consumption rates φc and φf.
この最後の操作つまり被害曲線を用いて寿命を
推定する方法の詳細を第１０図を用いて説明す
る。運転開始後運転時間ｔ及び繰返し数Ｎを記録
しておく。定期点検時にビツカース硬さHvと電
気抵抗Ｐとを測定してこれらの値から各々疲労被
害、クリープ被害に基く被害度φf，φcを推定す
る。ここまでは上記説明した通りである。次に、
各被害度φf，φcを被害曲線上にプロツトする。
即ちφf＝m′，φc＝m″とすれば、第１０図上の点
ｍが被害点となる。原点ｌと被害点ｍとを直線で
結び、更に被害曲線まで延長して被害曲線との交
点をｎとする。ｌからｍに至るに要した時間は
ｔ，繰返し数はＮであるので、余寿命は
tr＝ｔmn／lmまたはNr＝Ｎmn／lm
と表わせる。 The details of this last operation, that is, the method of estimating the life using the damage curve, will be explained using FIG. After the start of operation, record the operation time t and the number of repetitions N. At the time of periodic inspection, the Bitkers hardness Hv and electrical resistance P are measured, and from these values the damage degrees φf and φc based on fatigue damage and creep damage are estimated, respectively. The process up to this point is as explained above. next,
Plot each degree of damage φf and φc on the damage curve.
That is, if φf = m', φc = m'', then point m on Figure 10 becomes the damage point. Connect the origin l and damage point m with a straight line, extend it to the damage curve, and connect it with the damage curve. Let the intersection point be n. Since the time required to reach m from l is t and the number of repetitions is N, the remaining life can be expressed as t r =tmn/lm or Nr = Nmn/lm.
運転開始からの時間ｔや繰返し数Ｎが不明の場
合には更に運転を継続して次の定期点検時にビツ
カース硬さHvと電気抵抗Ｐとを測定して各々２
つのデータを得ておくと共に両定期点検間の運転
時間ｔ及び繰返し数Ｎを記録する事によつて余寿
命を求める事ができる。第１０図上で２回目の点
検時における被害点を０とし、１回目の被害点ｍ
とを結ぶ直線と被害曲線との交点をｎとするとこ
ろの場合の余寿命は
tr′＝tm0・on／moまたはNr′＝Nn0・on／mo
tr′：被害点０からｎまでの時間
tm0：ｍ点から０点までの時間
Nr′：０点からｎ点までの繰返し数
Nn0：ｍ点から０点までの繰返し数
となる。 If the time t from the start of operation or the number of repetitions N are unknown, continue the operation and measure the Vickers hardness Hv and electrical resistance P at the next periodic inspection.
The remaining life can be determined by obtaining two data and recording the operating time t between the two periodic inspections and the number of repetitions N. In Figure 10, the damage point at the second inspection is 0, and the damage point at the first inspection is m.
If n is the intersection of the straight line connecting the lines and the damage curve, the remaining life is t r ′=tm 0・on/mo or N r ′=N n0・on/mo t r ′: From the damage point 0 Time from point m to point n tm 0 : Time from point m to point 0 N r ': Number of repetitions from point 0 to point n N n0 : Number of repetitions from point m to point 0.
ｍ点から運転条件が変わり疲労被害のみが加わ
る様になつた場合にはｍ点からφf軸に平行に直
線を引いた被害曲線との交点Ｐを求め、両点ｍ，
Ｐからφf軸に降した点を各々m′，P′とすれば、
余寿命は
Nr＝Ｎ・m′P′／lm′
tr：ｍからｎまでの時間
ｔ：ｌからｎまでの時間
Nr：ｍからｎまでの繰返し数
Ｎ：ｌからｍまでの繰返し数
で表わされる。 If the operating conditions change from point m and only fatigue damage is added, find the intersection point P with the damage curve drawn from point m parallel to the φf axis, and
If the points dropped from P to the φf axis are m' and P', respectively,
The remaining life is Nr=N・m'P'/lm' t r : Time from m to n t: Time from l to n Nr: Number of repetitions from m to n N: Number of repetitions from l to m expressed.
ｍ点からクリープ被害のみが加わる様になる場
合は同様にし縦軸に関してm″，q′点を求め、こ
の時余寿命trを次式で得る。 If only creep damage starts to occur from point m, do the same thing and find points m'' and q' on the vertical axis, and then obtain the remaining life t r using the following formula.
tr＝ｔ・m″q′／lm″
疲労とクリープとが継続して加わるが、ｍ点か
ら運転モードが変わるなどして条件が変つた場合
には次の様にして求める。運転時間ｔと繰返し数
Ｎを記録して、ビツカース硬さと電気抵抗とを測
定し、既に説明した手順と同様にして被害度を求
める。この時被害点が図のｒ点にきたとすれば、
直線mrの延長線と被害曲線の交点をＳとして、
余寿命は
Nr＝Ｎrs／mrまたはTr＝Ｔrs／mr
と求まるのである。 t r =t・m″q′/lm″ Fatigue and creep continue to be added, but if conditions change due to a change in operating mode from point m, calculate as follows. The operating time t and the number of repetitions N are recorded, the Vickers hardness and electrical resistance are measured, and the degree of damage is determined in the same manner as described above. If the damage point reaches point r in the diagram at this time,
Let S be the intersection of the extension line of straight line mr and the damage curve,
The remaining life is calculated as Nr = Nrs/mr or Tr = Trs/mr.
以上の寿命予知法の手順をフロ−図で示したの
が第１１図である。この図を用いて手順を略述す
る。運転を開始すると運転条件である温度、時
間、繰返し数を記録する。定期点検時に破損の恐
れのある部分のビツカース硬さを測定して疲労寿
命消費率φfを求める。φfの求め方は第１０図に
説明した通りである。同時に電気抵抗Ｐを測定し
てクリープ時間比を推定し、クリープ寿命消費率
φcを求める。寿命消費率φf，φcを被害曲線に適
用して余寿命を評価し、余寿命tr，Nrが共に十
分大きい場合には運転を継続し、余寿命trまたは
Nrが小さいと判断された場合には運転を停止し、
補習または部品の取替を行なう。 FIG. 11 is a flowchart showing the steps of the above-mentioned life prediction method. The procedure will be briefly described using this figure. When the operation starts, the operating conditions such as temperature, time, and number of repetitions are recorded. The fatigue life consumption rate φf is determined by measuring the Bitker's hardness of parts at risk of breakage during periodic inspections. The method for determining φf is as explained in FIG. At the same time, the electric resistance P is measured, the creep time ratio is estimated, and the creep life consumption rate φc is determined. The remaining life is evaluated by applying the life consumption rates φf and φc to the damage curve, and if both the remaining life t r and Nr are sufficiently large, operation is continued and the remaining life t r or
If it is determined that Nr is small, the operation will be stopped,
Perform supplementary training or replace parts.
上記詳述した様に、本発明の方法は高温環境下
で荷重を受ける金属材料のビツカース硬さや電気
抵抗などのパラメータを得、これに基いて疲労被
害やクリープ被害が重畳した場合等の余寿命を推
定する事ができるものであり、破損等による事故
を未然に防ぐ事ができるなど実際上誠に有利な効
果を奏するものである。 As detailed above, the method of the present invention obtains parameters such as the Vickers hardness and electrical resistance of a metal material that is subjected to a load in a high-temperature environment, and based on these parameters, the remaining life when fatigue damage or creep damage occurs is determined. It is possible to estimate this, and it has a very advantageous effect in practice, such as being able to prevent accidents due to damage, etc.
第１図は焼なまし材の疲労過程中のビツカース
硬さ変化を示す図、第２図はビツカース硬さを応
力繰返し数比で整理した図、第３図は予加工材の
ビツカース硬さを応力繰返し数比で整理した図、
第４図はビツカース硬さで疲労寿命を推定する方
法の一例を示す図、第５図は焼なまし材のクリー
プ過程中の電気抵抗変化を示す図、第６図は電気
抵抗をクリープ時間比で整理した図、第７図な焼
なまし材のクリープ過程中の炭化物の凝集・粗大
化を示す図、第８図はクリープ被害を検出する方
法の一例を示す図、第９図ａ，ｂ，ｃ，ｄ第１０
図及び第１１図は各々疲労とクリープとが重畳し
た場合の被害を検出する手順を示す図である。
Figure 1 shows the change in Vickers hardness during the fatigue process of annealed material, Figure 2 shows the Vickers hardness organized by stress repetition rate, and Figure 3 shows the Vickers hardness of pre-processed material. Diagram organized by stress repetition rate ratio,
Figure 4 is a diagram showing an example of a method for estimating fatigue life using Vickers hardness, Figure 5 is a diagram showing changes in electrical resistance during the creep process of annealed material, and Figure 6 is a diagram showing electrical resistance as a ratio of creep time. Figure 7 is a diagram showing the agglomeration and coarsening of carbides during the creep process of annealed material, Figure 8 is a diagram showing an example of a method for detecting creep damage, and Figure 9 a, b , c, d 10th
11 and 11 are diagrams each showing a procedure for detecting damage when fatigue and creep overlap.
Claims (1)
予知する方法において、該金属材料のビツカース
硬さと電気抵抗とを求める工程、既知のビツカー
ス硬さと応力繰返し疲労試験による疲労破壊回数
に対する応力繰返し数の比によつて算出される疲
労寿命消費率との関係に基づいて前記求められた
ビツカース硬さに対応する疲労寿命消費率を推定
する工程、既知の電気抵抗値とクリープ試験によ
るクリープ変形量との関係に基づいて前記求めら
れた電気抵抗値に対応するクリープ変形量を推定
する工程、既知の応力とクリープ変形量及びクリ
ープ時間との関係を示す線図に基づいて前記推定
されたクリープ変形量から前記金属材料の使用温
度及び時間に対応する応力を推定する工程、既知
の電気抵抗値とクリープ試験によるクリープ破断
時間に対するクリープ時間の比によつて算出され
るクリープ寿命消費率との関係に基づいて前記推
定された応力と前記使用温度及び時間に対応する
クリープ寿命消費率を推定する工程、既知の疲労
寿命消費率とクリープ寿命消費率との関係に基づ
いて表わされる被害曲線図に前記推定された疲労
寿命消費率とクリープ寿命消費率をプロツトし、
該プロツトした点と前記被害曲線との関係に基づ
いて前記金属材料の余寿命を推定する工程を含む
ことを特徴とする金属材料の寿命予知方法。1. In a method for predicting the life of a metal material that is subjected to a load in a high-temperature environment, the process of determining the Vickers hardness and electrical resistance of the metal material, and the calculation of the known Vickers hardness and the number of stress cycles for the number of fatigue failures in a stress cyclic fatigue test. a step of estimating the fatigue life consumption rate corresponding to the determined Bitkers hardness based on the relationship with the fatigue life consumption rate calculated by the ratio, and a step of estimating the fatigue life consumption rate corresponding to the determined Bitkers hardness, a step of estimating the amount of creep deformation corresponding to the determined electrical resistance value based on the relationship, from the estimated amount of creep deformation based on a diagram showing the relationship between the known stress, the amount of creep deformation, and the creep time; A step of estimating the stress corresponding to the operating temperature and time of the metal material, based on the relationship between the known electrical resistance value and the creep life consumption rate calculated by the ratio of the creep time to the creep rupture time by a creep test. A step of estimating the creep life consumption rate corresponding to the estimated stress and the operating temperature and time, and adding the estimated stress to a damage curve diagram expressed based on the relationship between the known fatigue life consumption rate and the creep life consumption rate. Plot the fatigue life consumption rate and creep life consumption rate,
A method for predicting the life of a metal material, comprising the step of estimating the remaining life of the metal material based on the relationship between the plotted points and the damage curve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57070437A JPS58189557A (en) | 1982-04-28 | 1982-04-28 | Predicting method of life of metallic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57070437A JPS58189557A (en) | 1982-04-28 | 1982-04-28 | Predicting method of life of metallic material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58189557A JPS58189557A (en) | 1983-11-05 |
| JPH0142381B2 true JPH0142381B2 (en) | 1989-09-12 |
Family
ID=13431457
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57070437A Granted JPS58189557A (en) | 1982-04-28 | 1982-04-28 | Predicting method of life of metallic material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58189557A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4522828B2 (en) * | 2004-11-18 | 2010-08-11 | 住友金属テクノロジー株式会社 | Remaining life diagnosis method for Cr-Mo heat resistant steel |
| JP6686645B2 (en) * | 2016-04-07 | 2020-04-22 | 日本製鉄株式会社 | Steel quality assurance method and fatigue property estimation method |
-
1982
- 1982-04-28 JP JP57070437A patent/JPS58189557A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58189557A (en) | 1983-11-05 |
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