JPH0466863A - Residual stress measuring method by steel working - Google Patents
Residual stress measuring method by steel workingInfo
- Publication number
- JPH0466863A JPH0466863A JP2180795A JP18079590A JPH0466863A JP H0466863 A JPH0466863 A JP H0466863A JP 2180795 A JP2180795 A JP 2180795A JP 18079590 A JP18079590 A JP 18079590A JP H0466863 A JPH0466863 A JP H0466863A
- Authority
- JP
- Japan
- Prior art keywords
- residual stress
- processing
- voltage value
- permeability
- working
- 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.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 41
- 239000010959 steel Substances 0.000 title claims abstract description 41
- 238000000034 method Methods 0.000 title claims description 20
- 230000005291 magnetic effect Effects 0.000 claims abstract description 70
- 230000035699 permeability Effects 0.000 claims abstract description 47
- 230000008859 change Effects 0.000 claims abstract description 30
- 230000000717 retained effect Effects 0.000 claims abstract description 23
- 238000001514 detection method Methods 0.000 claims abstract description 17
- 239000000463 material Substances 0.000 claims description 41
- 229910001566 austenite Inorganic materials 0.000 claims description 23
- 238000012545 processing Methods 0.000 claims description 23
- 238000012805 post-processing Methods 0.000 claims description 16
- 238000007781 pre-processing Methods 0.000 claims description 16
- 238000005259 measurement Methods 0.000 abstract description 7
- 229910000976 Electrical steel Inorganic materials 0.000 abstract description 4
- 238000000691 measurement method Methods 0.000 description 17
- 230000004907 flux Effects 0.000 description 9
- 230000009467 reduction Effects 0.000 description 7
- 230000005284 excitation Effects 0.000 description 6
- 238000003754 machining Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 229910000734 martensite Inorganic materials 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000005480 shot peening Methods 0.000 description 4
- 230000005415 magnetization Effects 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000001066 destructive effect Effects 0.000 description 1
- 230000005674 electromagnetic induction Effects 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 230000005389 magnetism Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000009659 non-destructive testing Methods 0.000 description 1
- 230000005298 paramagnetic effect Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は、歯車、車軸等の部品に用いられる鋼材にショ
ットピーニング等の残留応力が残る加工を行なった場合
における残留応力の測定方法に関する。この測定方法は
加工された鋼材の硬さ、疲労強度等のめヤすとして利用
できる。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for measuring residual stress when a steel material used for parts such as gears and axles is subjected to processing such as shot peening that leaves residual stress. This measurement method can be used as a measure of the hardness, fatigue strength, etc. of processed steel materials.
［従来の技術］
特開昭’１８−４３９５４号公報には材料（ｉｉｌｌ材
）の非破壊選別方法が開示されている。この選別方法は
、材料の硬さと保磁力との間に一定の関係かあることを
利用し、硬さを選別すべき所望の段階に区分設定し、各
選別限界の硬さに対応する保磁力を求めてあき、材料を
飽和励磁した１変、選別限界の硬さに対応する保磁力に
それぞれ減磁し、各減磁状態にあける磁束密度の正、負
を検出し、その磁束密度の正あるいは負の数の多少によ
り所望の段階の硬さに選別するものである。[Prior Art] Japanese Patent Application Laid-Open No. 18-43954 discloses a method for non-destructive sorting of materials (Iill materials). This sorting method takes advantage of the fact that there is a certain relationship between material hardness and coercive force, sets the hardness into desired stages to be sorted, and sets the coercive force corresponding to the hardness at each sorting limit. The material is saturated and excited, and the coercive force corresponding to the hardness of the selection limit is demagnetized, and the positive and negative magnetic flux densities in each demagnetized state are detected. Alternatively, the desired level of hardness is selected depending on the degree of negative number.
また、磁気による高周波焼入れ軸の残留応力の測定方法
か知られている。この測定方法は、積層珪素鋼板からな
るコ字形状の磁芯に励磁コイル及び゛検出コイルを巻き
つけた２個のセンサを用いるものであって、Ｘ線応力測
定装置より求めた基準となる残留応力値と、各センサを
車軸に軸方向及び円周方向に当接することにより得られ
る出力とを比較し、その車軸の残留応力を求めるもので
ある。また、上記２個のセンサを互いに直角に組合せた
磁気異方性センサを用い、軸方向及び円周方向の出力検
出を同時に行なう方法も知られている（非破壊検査第３
５巻第２号（６２，２，２０））［発明が解決しようと
する課題］
しかし、上記各従来の技術はいずれも、軸方向及び円周
方向にあける引張り及び圧縮による保磁力の変化に着目
したものであり、つまり直角方向において主応力差と主
応力方向の透磁率の差とに比例関係かあることを利用し
たものであり、その適用範囲は応力状態か異方性である
場合の測定に限られるものであった。このため、かかる
技術では、応力状態が等方性でおるショットピーニング
加工を行なった場合には直角方向に透磁率の差を生じな
いため、残留応力を正確に測定することか不可能であっ
た。A method for measuring residual stress in an induction hardened shaft using magnetism is also known. This measurement method uses two sensors in which an excitation coil and a detection coil are wound around a U-shaped magnetic core made of laminated silicon steel plates. The residual stress of the axle is determined by comparing the stress value with the output obtained by contacting each sensor with the axle in the axial and circumferential directions. Furthermore, a method is also known in which output detection in the axial and circumferential directions is simultaneously performed using a magnetic anisotropic sensor in which the above two sensors are combined at right angles to each other (Non-destructive Testing No. 3).
(Vol. 5, No. 2 (62, 2, 20)) [Problems to be Solved by the Invention] However, all of the above-mentioned conventional techniques cannot cope with changes in coercive force caused by tension and compression in the axial and circumferential directions. In other words, it takes advantage of the fact that there is a proportional relationship between the principal stress difference in the perpendicular direction and the difference in magnetic permeability in the principal stress direction, and its application range is in the case of stress state or anisotropy. It was limited to measurements. For this reason, with this technique, when shot peening is performed in which the stress state is isotropic, no difference in magnetic permeability occurs in the perpendicular direction, making it impossible to accurately measure residual stress. .
また、特開昭４８−４３９５４号開示の方法では、まず
直流電流を用いて鋼材を磁気的に飽和させ、しかる後に
磁気飽和に達したときの磁場とは逆方向に磁場を増加さ
せることにより、磁化かＯとなる保磁力を測定する。こ
のため、この方法ては、磁気飽和に到達させる磁場と、
磁化をＯにする磁場とを測定対象たる鋼材に加える必要
があり、操作性に劣ることから生産ラインへの適用か困
難であった。Furthermore, in the method disclosed in JP-A-48-43954, the steel material is first magnetically saturated using a direct current, and then the magnetic field is increased in the opposite direction to the magnetic field when magnetic saturation is reached. Measure the coercive force at which the magnetization becomes O. For this reason, this method requires a magnetic field to reach magnetic saturation,
It is necessary to apply a magnetic field that changes the magnetization to O to the steel material being measured, and it is difficult to apply it to a production line because of poor operability.
さらに、上記公報記載の方法では、磁性体を磁化させる
と歪みを生じるという「磁気歪み効果」の逆の作用から
、鋼材を磁気飽和に到達させる際、歪みか鋼材に生じて
しまい、この歪みに基づいて鋼材の残留応力か変化して
しまう。このため、測定した保磁力と鋼材の硬さの一要
素たる残留応力との相関関係がくずれ、鋼材の硬さを正
確に測定するのに不十分な場合かあった。Furthermore, in the method described in the above publication, due to the opposite effect of the "magnetostrictive effect" in which distortion occurs when a magnetic material is magnetized, distortion occurs in the steel material when the steel material reaches magnetic saturation. The residual stress of the steel material changes accordingly. For this reason, the correlation between the measured coercive force and the residual stress, which is one element of the hardness of the steel material, is broken, and there have been cases where it is insufficient to accurately measure the hardness of the steel material.
したかつて、従来の技術により、例えばショットピーニ
ング後の鋼材の残留応力を正確に測定せんとすれば、Ｘ
線応力測定装置を用いて個々（こ測定を行なわざるをえ
ず、各ｖＡ材の表面を電解研磨する必要性から測定後の
鋼材の使用等が不能になるとともに、正確な測定値を求
めるべく測定数を増やす必要か生じるため測定に長時間
を要するという不具合かあった。In the past, if you wanted to accurately measure the residual stress of a steel material after shot peening using conventional techniques,
This measurement had to be carried out individually using a linear stress measuring device, and the necessity of electrolytically polishing the surface of each vA material made it impossible to use the steel material after the measurement, and in order to obtain accurate measured values. There was a problem in that it took a long time to measure because the number of measurements needed to be increased.
本発明は、上記従来の不具合に鑑みてなされたものであ
って、鋼材の加工による応力状態が等方性である加工を
行なった場合にも、鋼材を破壊することなく、操作性よ
くかつ正確に残留応力を測定可能な残留応力の測定方法
を提供することを目的とする。The present invention has been made in view of the above-mentioned conventional problems, and even when machining steel materials in which the stress state is isotropic, the present invention does not destroy the steel materials and has good operability and accuracy. The purpose of this study is to provide a method for measuring residual stress that can be used to measure residual stress.
［課題を解決するための手段］
本発明者は、残留応力が発生する加工を行なった場合に
おける鋼材の特性変化を鋭意研究した結果、以下の測定
方法を発見するに至った。[Means for Solving the Problems] As a result of intensive research into changes in the properties of steel materials when processed to generate residual stress, the inventors discovered the following measurement method.
すなわち、本発明の鋼材の加工による残留応力の測定方
法は、残留オーステナイト組織をもつ加工前の鋼材の透
磁率を検出する加工前透磁率検出工程と、
該鋼材の加工後にあける透磁率を検出する加工後透磁率
検出工程と、
検出された加工前透磁率と加工後透磁率との変化値から
残留応力を算出する算出工程とからなることを特徴とす
るものである。That is, the method for measuring residual stress due to processing of steel materials of the present invention includes a pre-processing magnetic permeability detection step of detecting the magnetic permeability of a steel material with retained austenite structure before processing, and a step of detecting the magnetic permeability of the steel material after processing. This method is characterized by comprising a post-processing magnetic permeability detection step, and a calculation step of calculating residual stress from the detected change value between the pre-processing magnetic permeability and the post-processing magnetic permeability.
ここに、加工前とは、鋼材の一部に加工を施す場合であ
れば、その加工を施す部分以外の部分を含む意である。Here, before processing, in the case where a part of the steel material is processed, it includes a part other than the part to be processed.
透磁率の検出は、積層珪素鋼板等からなる磁芯と、この
磁芯に巻きつけられ交流電流か印加される励磁コイルと
、磁芯に巻きつけられ透ｍ率を電圧値として出力する検
出コイルとからなるセンサを用いて行なうことかできる
。Magnetic permeability is detected using a magnetic core made of laminated silicon steel plates, an excitation coil wound around this magnetic core to which an alternating current is applied, and a detection coil wound around the magnetic core and outputting the permeability as a voltage value. This can be done using a sensor consisting of.
残留応力の算出は、予めＸ線応力測定装置等より求めた
基準となる残留応力値と透磁率の変化値との相対関係を
求めておき、かかる相対関係から個々の変化値に相当す
る残留応力を求めることにより行なうことかできる。To calculate the residual stress, first find the relative relationship between the reference residual stress value obtained using an X-ray stress measuring device, etc. and the change value of magnetic permeability, and then calculate the residual stress corresponding to each change value from this relative relationship. This can be done by asking for.
［作用］
本発明者は、鋼材の残留オーステナイト組織か加工によ
って加工誘起マルテンザイ１〜組織に変態し、これによ
って大きく透磁率か変化１−るとともに、この透磁率の
変化値が残留応力と比例的関係にあることを見出した。[Function] The present inventor has discovered that the retained austenite structure of the steel material transforms into a deformation-induced martenzyme structure due to processing, which causes a large change in magnetic permeability, and that the value of change in magnetic permeability is proportional to the residual stress. I found out that there is a relationship.
したかつて、まず残留オースナナ１１〜組織をもつ加工
前の鋼材の透ｆｔｉ率を検出し、しかる後に鋼材の加工
後にお（ブる透磁率を検出し、これら検出された加工前
透磁率と加工後透磁率との変化値を求めれば、加工後の
鋼材の残留応力を算出することができる。In the past, we first detected the permeability of the steel material with residual austenana 11 ~ structure before processing, then detected the permeability of the steel material after processing, and calculated the detected permeability before processing and after processing. By determining the change value from the magnetic permeability, the residual stress of the steel material after processing can be calculated.
［実施例］
以下、本発明を具体化した実施例を図面を参照しつつ説
明する。[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.
（鋼材）
本実施例では、第１図に示すように、鋼材として車両用
ドライブピニオン１を用いている。このドライブピニオ
ン１は、傘部１１と軸部１２とをもつ。加工前のドライ
ブピニオン１は、浸炭鋼を浸炭処理したものであり、約
８０％のマルテンサイト組織と約２０％の残留オーステ
ナイト組織とからなる。(Steel Material) In this embodiment, as shown in FIG. 1, a vehicle drive pinion 1 is used as the steel material. This drive pinion 1 has an umbrella part 11 and a shaft part 12. The drive pinion 1 before processing is made of carburized steel and consists of about 80% martensite structure and about 20% retained austenite structure.
（測定装置）
使用した測定装置２も第１図に示す。この測定装置２は
、ドライブピニオン１の傘部１１に当接される傘部セン
サ２１と、ドライブピニオン１の軸部１２に当接される
軸部センサ２２と、これら傘部センサ２１及び軸部セン
サ２２と接続される計測器２３とからなる。(Measuring device) The measuring device 2 used is also shown in FIG. This measuring device 2 includes an umbrella sensor 21 that is in contact with the umbrella 11 of the drive pinion 1, a shaft sensor 22 that is in contact with the shaft 12 of the drive pinion 1, and the umbrella sensor 21 and the shaft. It consists of a sensor 22 and a measuring device 23 connected to it.
傘部センサ２１は、第２図に示すように、積層珪素鋼板
からなるコ字形状の磁芯２１０と、この磁芯２１０に巻
きつけられ交流電流が印加される励磁コイル２１１と、
磁芯２１０に巻きつけられ電磁誘導により電圧値を出力
する検出コイル２１２とからなる。磁芯２１０は、第３
図に示すように、各先端部分かドライブピニオン１の傘
部１１の歯溝とほぼ確実に当接するように型対称に形成
されており、各先端部分の側壁には磁束を各先端部分に
集中させるとともに耐摩耗性を向上させるべくセラミッ
ク等からなるコーティング層２１０ａか形成されている
。As shown in FIG. 2, the umbrella sensor 21 includes a U-shaped magnetic core 210 made of a laminated silicon steel plate, an excitation coil 211 wound around the magnetic core 210, and to which an alternating current is applied.
It consists of a detection coil 212 that is wound around a magnetic core 210 and outputs a voltage value by electromagnetic induction. The magnetic core 210 is the third
As shown in the figure, each tip is formed symmetrically so that it almost definitely comes into contact with the tooth groove of the umbrella part 11 of the drive pinion 1, and the side wall of each tip is designed to concentrate magnetic flux to each tip. A coating layer 210a made of ceramic or the like is formed to improve wear resistance.
第１図に示す軸部センサ２２は、第２図及び第３図に示
す傘部センサ２１と基本的に同一であるが、ただ磁芯の
各先端部分かドライブピニオン１の軸部１２とほぼ確実
に当接するように型対称に形成されている点か異なる。The shaft sensor 22 shown in FIG. 1 is basically the same as the umbrella sensor 21 shown in FIGS. The difference is that it is formed symmetrically to ensure secure contact.
計測器２３は、第２図に示すように、発振器２３１と、
この発振器２３１と接続され励磁コイル２１１に交流電
流を印加する増幅器２３２と、検出コイル２１２と接続
され電圧値を増幅させる増幅器２３３と、増幅器２３３
と接続された入出力装置２３４と、入出力装置２３４と
接続されたマイコン２３５と、入出力装置２３４と接続
された表示装置２３６とからなる。As shown in FIG. 2, the measuring instrument 23 includes an oscillator 231,
An amplifier 232 is connected to the oscillator 231 and applies an alternating current to the excitation coil 211; an amplifier 233 is connected to the detection coil 212 and amplifies the voltage value;
, a microcomputer 235 connected to the input/output device 234 , and a display device 236 connected to the input/output device 234 .
（測定方法１）
本実施例では、加工としてショットピーニング（以下、
単にショットという。）を上記ドライブピニオン１に行
ない、上記測定装置２を用いて残留応力の測定を行なっ
た。(Measurement method 1) In this example, shot peening (hereinafter referred to as
It's simply called a shot. ) was applied to the drive pinion 1, and the residual stress was measured using the measuring device 2.
（加工前透磁率検出工程）
第１図に示すように、まずショッｉ〜前のドライブピニ
オン１の傘部１１に傘部センサ２１を当接する。これに
より、第２図に示すように、ドライブピニオン１の傘部
１１は深ざｔの範囲内で磁束を生じる。これにより、計
測器２３ては、傘部センサ２１の電圧値（加工前電圧値
；Ｖｏ）が検出される。この加工前電圧値（Ｖｏ ）は
加工前透磁率（μ０）と以下の相関関係をもつ。(Pre-processing magnetic permeability detection step) As shown in FIG. 1, first, the cap sensor 21 is brought into contact with the cap 11 of the drive pinion 1 before the shot i. As a result, as shown in FIG. 2, the umbrella portion 11 of the drive pinion 1 generates magnetic flux within the range of depth t. Thereby, the measuring device 23 detects the voltage value of the umbrella sensor 21 (voltage value before processing; Vo). This pre-processing voltage value (Vo) has the following correlation with the pre-processing magnetic permeability (μ0).
すなわち、傘部センサ２１の励磁コイル２１１に１５ｋ
Ｈｚの交流電流を印加することにより、ドライブピニオ
ン１の傘部１１には、第２図に示すように、表面より１
００μｍ程度までの深さ士で磁束（Φ）か発生する。こ
の磁束（Φ）の発生量は、深さｔにおける透磁率（μ）
によって決定される。That is, 15k is applied to the excitation coil 211 of the umbrella sensor 21.
By applying an alternating current of Hz, the umbrella portion 11 of the drive pinion 1 is heated by 1 from the surface as shown in FIG.
Magnetic flux (Φ) is generated at a depth of about 00 μm. The amount of generated magnetic flux (Φ) is determined by the magnetic permeability (μ) at depth t.
determined by
この透磁率（μ）と磁気抵抗（Ｒｍ）とは次の関係をも
つ。The magnetic permeability (μ) and magnetic resistance (Rm) have the following relationship.
Ｒｍ＝ｆ（１／μｍ５）ｄｓ−・−（１）式％式％）
この（１）式かられかるように、磁気抵抗（Ｒｍ）と透
磁率（μ）とは反比例の関係にあり、透磁率（μ）か小
さいと、磁気抵抗（Ｒｍ）は高くなる。この磁気抵抗（
Ｒｍ）と磁束（Φ）とは次の関係をもつ。Rm=f(1/μm5)ds-・-(1) formula % formula %) As can be seen from this formula (1), magnetic resistance (Rm) and magnetic permeability (μ) are in an inversely proportional relationship, The smaller the magnetic permeability (μ), the higher the magnetic resistance (Rm). This magnetic resistance (
Rm) and magnetic flux (Φ) have the following relationship.
Φ＝Ｖｍ／Ｒｍ・・・・・・・・・・・・・・・・・・
・・・・・・（２）式（但し、Ｖｍ；センサの起磁力（
Ｖｍ＝Ｉ−Ｎ）ここに、■；励磁電流、Ｎ；］イル巻数
）この（２）式かられかるように、磁束（Φ）は磁気抵
抗（Ｒｍ）が小さいほど、つまり透磁率（μ）が大きい
ほど、発生量か多くなる。よって、一定の起磁力（Ｖｍ
）でドライブピニオン１を励磁すると、深さｔ内の透磁
率（μ）によって磁気抵抗（Ｒｍ）か定まり、最終的に
（２）式に基づいて磁束（Φ）の発生状態か決定される
。Φ=Vm/Rm・・・・・・・・・・・・・・・・・・
......Formula (2) (where, Vm; magnetomotive force of the sensor (
Vm=I-N) Here, ■; excitation current; ) is larger, the amount generated increases. Therefore, a constant magnetomotive force (Vm
), when the drive pinion 1 is excited, the magnetic resistance (Rm) is determined by the magnetic permeability (μ) within the depth t, and finally the state of generation of the magnetic flux (Φ) is determined based on equation (2).
この磁束（Φ）によって検出コイル２１２に誘起される
電圧値（Ｖ）が次の関係で求まる。The voltage value (V) induced in the detection coil 212 by this magnetic flux (Φ) is determined by the following relationship.
■＝−ｄΦ／ｄｔ・・・・・・・・・・・・・・・・・
・・・・・・・（３）式以上の相関関係の下、計測器２
３の表示装置２３６に加工前電圧値（ＶＯ）が表示され
る。一方、この加工前電圧値（Ｖｏ ）をもつドライブ
ピニオン１の最大残留圧縮応力（以下残留応力（Ｒ５ｏ
）という。〉をＸ線応力測定装置等より求めておく。■=-dΦ/dt・・・・・・・・・・・・・・・・・・
......Under the correlation of equation (3) or higher, measuring instrument 2
The pre-processing voltage value (VO) is displayed on the display device 236 of No. 3. On the other hand, the maximum residual compressive stress (hereinafter referred to as residual stress (R5o) of the drive pinion 1 with this pre-processing voltage value (Vo)
). > is determined using an X-ray stress measuring device, etc.
（加工後透磁率検出工程）
次いて、傘部１１に所定のショットを施したドライブピ
ニオン１を用意し、第１図に示すように、このドライブ
ピニオン１の傘部１１に傘部センサ２１を当接する。こ
れにより、計測器２３ては、上記（加工前透磁率検出工
程）と同様、傘部センサ２１の電圧値（加工後電圧値；
Ｖｌ）か検出される。この加工後電圧値（Ｖｌ）も、上
記加工前電圧値（Ｖｏ ）と加工前透磁率（μ０）との
関係と同様、加工後透磁率（μｍ）と相関関係をもつ。(Post-processing magnetic permeability detection step) Next, a drive pinion 1 with a predetermined shot applied to the cap portion 11 is prepared, and a cap sensor 21 is attached to the cap portion 11 of the drive pinion 1 as shown in FIG. come into contact with As a result, the measuring instrument 23 detects the voltage value of the umbrella sensor 21 (voltage value after processing), similar to the above (pre-processing permeability detection step).
Vl) is detected. This post-processing voltage value (Vl) also has a correlation with the post-processing magnetic permeability (μm), similar to the relationship between the pre-processing voltage value (Vo) and the pre-processing magnetic permeability (μ0).
こうして、表示装置２３６に加工後電圧値（Ｖｌ）か表
示される。この加工後電圧値（ｖｌ）をもつドライブピ
ニオン１の残留応力（Ｒ８Ｉ）をもＸ線応力測定装置等
より求めてあく。In this way, the post-processing voltage value (Vl) is displayed on the display device 236. The residual stress (R8I) of the drive pinion 1 having this post-processing voltage value (vl) is also determined using an X-ray stress measuring device or the like.
そして、複数のショットの段階において、上記（加工後
透磁率検出工程）を同様に行い、各加工後電圧値（Ｖ２
〜Ｖ４）をもつドライブピニオン１の各残留応力（Ｒ５
２〜Ｒ５４）をＸ線応力測定装置等より求めておく。Then, at the stage of multiple shots, the above (post-processing magnetic permeability detection process) is performed in the same way, and each post-processing voltage value (V2
~V4) of each residual stress (R5) of the drive pinion 1
2 to R54) are determined using an X-ray stress measuring device or the like.
（締出工程）
ドライブピニオン１における各力Ｕ工後電ｒＦ値（ｖｏ
〜Ｖ４）と、各残留応力（Ｒ５２〜Ｒ５４）との関係を
第４図に示す。これを入出力装置２３４より入力する。(Clamping process) The electric rF value after each force U in the drive pinion 1 (vo
~V4) and each residual stress (R52~R54) is shown in FIG. This is input from the input/output device 234.
以下、新たなドライブピニオン１に傘部センサ２１を当
接するたび、計測器２３ては、加工後電圧値（ＶＸ）か
検出され、この加工後電圧値（ＶＸ）と加工前電圧値（
Ｖｏ ）との変化量（Ｖ。Thereafter, every time the umbrella sensor 21 comes into contact with a new drive pinion 1, the measuring device 23 detects the post-processing voltage value (VX), and the post-processing voltage value (VX) and the pre-processing voltage value (
The amount of change (V.
ＶＸ−ΔＶ）か求められ、この変化量（△Ｖ）と上記第
４図に示す関係とから残留応力（Ｒ５ｘ ）が算出され
る。VX-ΔV) is determined, and the residual stress (R5x) is calculated from this amount of change (ΔV) and the relationship shown in FIG. 4 above.
こうして計測器２３によって測定された残留応力と残留
オーステナイトの減少率との関係を第５図に示す。第５
図から残留オーステナイトの減少率と残留応力との間に
は比例的関係かあることか確認される。これは、第６図
及び第７図に示すように、残留オーステナイト組織かシ
ョットされることにより、加工誘起マルテンサイト変態
による体積膨張を受けるものと、残留オーステナイト組
織のままで塑性変形を受（プるものとに分けられ、これ
らにより傘部１１に残留応力か付与されると考えられる
からである。FIG. 5 shows the relationship between the residual stress measured by the measuring device 23 and the reduction rate of retained austenite. Fifth
The figure confirms that there is a proportional relationship between the reduction rate of retained austenite and residual stress. As shown in Figures 6 and 7, the retained austenite structure undergoes volume expansion due to deformation-induced martensitic transformation when shot, and the retained austenite structure undergoes plastic deformation (procedure). This is because it is thought that residual stress is applied to the umbrella portion 11 due to these.
また、残留オーステナイトの減少率と傘部センサ２１の
電圧値（加工前電圧値及び加工後電圧値）との関係を第
８図に示す。この第８図より、残留オーステナイトの減
少率か増すと、電圧値が高くなることがわかる。これは
、オーステナイト組織が常磁性であり、マルテンサイト
組織が強磁性であるため、ショットによって残留オース
テナイト組織か加工誘起マルテンサイト組織に変態する
ことにより、大きく透磁率が変化し、磁気抵抗が減少し
、磁束の発生量か増加して電圧値か高くなるからである
。Moreover, the relationship between the reduction rate of retained austenite and the voltage value of the cap sensor 21 (voltage value before machining and voltage value after machining) is shown in FIG. From FIG. 8, it can be seen that as the reduction rate of retained austenite increases, the voltage value increases. This is because the austenite structure is paramagnetic and the martensite structure is ferromagnetic, so the shot transforms into a retained austenite structure or a deformation-induced martensite structure, resulting in a large change in magnetic permeability and a decrease in magnetic resistance. This is because the amount of magnetic flux generated increases and the voltage value increases.
さらに、計測器２３によって測定された残留応力と電圧
値との関係を第９図に示す。この第９図より、残留応力
と電圧値とは比例的関係にあることがわかる。したかっ
て、１−ライブピニオン１のショット前の電圧値を検出
し、この後にショット後の電圧値を検出し、これらの電
圧値の変化量を求めることにより、ショット後のドライ
ブピニオン１の残留応力を締出てきることかわかる。ま
た、このとき、直流電流により磁気飽和に到達させる磁
場と、磁化をＯにする磁場とをドライブピニオン１に加
える必要かなく、かつ磁気歪み効果により誤差となる歪
みかドライブピニオン１に生じることもない。このため
、この測定方法によれば、測定後のドライブピニオン１
の使用が可能であるとともに、その測定を操作性よく、
かつ正確に行なうことができる。Furthermore, the relationship between the residual stress measured by the measuring instrument 23 and the voltage value is shown in FIG. From FIG. 9, it can be seen that there is a proportional relationship between residual stress and voltage value. Therefore, by detecting the voltage value of 1-live pinion 1 before the shot, then detecting the voltage value after the shot, and finding the amount of change in these voltage values, the residual stress of the drive pinion 1 after the shot can be calculated. I know it's going to shut me out. In addition, at this time, it is not necessary to apply a magnetic field to reach magnetic saturation using a direct current and a magnetic field to change the magnetization to O to the drive pinion 1, and there is no need to apply distortion that causes an error to the drive pinion 1 due to the magnetostrictive effect. do not have. Therefore, according to this measurement method, the drive pinion 1 after measurement
In addition to being able to use the
And it can be done accurately.
なお、第１０図にショット前の残留オーステナイト量と
残留応力との関係を示す。第１０図かられかるように、
ショット前の残留オーステナイト量によって、残留応力
が最大とされる領域が存在する。本実施例では、この残
留応力が最大とされる残留オーステナイト量の範囲を適
用範囲としている。また、第１１図に示すように、この
適用範囲をショット条件の目安とされるアークハイト量
で示せば、比較的高強度領域の０．６〜０．８８の範囲
である。Note that FIG. 10 shows the relationship between the amount of retained austenite before shot and the residual stress. As can be seen from Figure 10,
Depending on the amount of retained austenite before shot, there is a region where the residual stress is maximum. In this embodiment, the applicable range is the amount of retained austenite in which this residual stress is maximum. Moreover, as shown in FIG. 11, if this application range is expressed by the amount of arc height used as a guideline for shot conditions, it is in the range of 0.6 to 0.88, which is a relatively high strength region.
（測定方法１の利用１） 上記測定方法１は生産ラインへ適用可能である。(Use of measurement method 1 1) The above measurement method 1 can be applied to a production line.
この場合、例えば第１２図に示すように、ライン上で搬
送される個々のドライブピニオン１のショット後の加工
後電圧値（Ｖｘ ）を検出し、−旦求めた加工前電圧値
（＼１０）と各加工後電圧値（ＶＸ）とから各変化量（
Ｖｏ Ｖｘ−△Ｖ）を求める。そして、各変化量（Δ
Ｖ）が所定範囲内にあるか否かの判定をマイコン２３５
で行ない、ライン上のドライブピニオン１の選別を行な
う。このときの残留応力と電圧値との関係を第１３図に
示す。これにより、所定の疲労強度等をもつドライブピ
ニオン１を充分な精度で選別できることかわかる。In this case, for example, as shown in FIG. 12, the post-processing voltage value (Vx) after the shot of each drive pinion 1 conveyed on the line is detected, and the pre-processing voltage value (\10) determined previously is detected. The amount of change (
Find Vo Vx-△V). Then, each amount of change (Δ
The microcomputer 235 determines whether V) is within a predetermined range.
to select the drive pinions 1 on the line. The relationship between residual stress and voltage value at this time is shown in FIG. This shows whether drive pinions 1 having a predetermined fatigue strength etc. can be selected with sufficient accuracy.
（測定方法１の利用２）
また、個々のドライブピニオン１において残留オーステ
ナイト量が変動するようであれば、例えば第１４図に示
すように、ライン上で搬送される個々のドライブピニオ
ン１のショット前の加工前電圧値（Ｖｙ ）及びショッ
ト後の加工後電圧値（Ｖｚ）を検出し、各加工前電圧値
（Ｖｙ ）及び各加工後電圧値（Ｖｚ）から各変化量（
Ｖｙ −ＶＺ＝△Ｖ）を求める。そして、各変化量（△
Ｖ）か所定範囲内にあるか否かの判定をマイコン２３５
て行ない、ライン上のドライブピニオン１の選別を行な
う。このときの残留応力と電圧値との関係を第１５図に
示す。これにより、個々のドライブピニオン１の残留オ
ーステナイト量の変動を無視できるため、所定の疲労強
度等をもつドライブピニオン１をより一層精度よく選別
できることがわかる。(Use of measurement method 1 2) If the amount of retained austenite varies in each drive pinion 1, for example, as shown in FIG. Detect the pre-processing voltage value (Vy) and the post-processing voltage value (Vz) after the shot, and calculate each change amount (Vy) from each pre-processing voltage value (Vy) and each post-processing voltage value (Vz).
Find Vy - VZ = △V). Then, each amount of change (△
The microcomputer 235 determines whether or not V) is within a predetermined range.
Then, the drive pinions 1 on the line are sorted. The relationship between residual stress and voltage value at this time is shown in FIG. This makes it possible to ignore variations in the amount of retained austenite in each drive pinion 1, so that it is possible to select drive pinions 1 having a predetermined fatigue strength, etc. with even greater precision.
（測定方法２）
上記測定方法１では、傘部センサ２１のみにより加工前
及び加工後の電圧値を測定したが、傘部センサ２１によ
りショットを施した部分の電圧値（ショット電圧値：Ｖ
ａ）を測定し、軸部センサ２２によりショットを施さな
い部分の電圧値（未ショット電圧値：Ｖｂ）を測定する
ことにより残留応力を測定することも可能である。この
場合、ショット電圧値（Ｖａ）と未ショット電圧値（■
ｂ）との変化率（Ｖａ ／Ｖｂ ＝ｒ （％））が求め
られ、この変化率（ｒ）から残留応力が算出される。こ
のとき、残留応力と変化率との関係を第１６図に示す。(Measurement method 2) In the measurement method 1 described above, the voltage values before and after processing were measured only by the umbrella sensor 21, but the voltage value of the portion where the shot was applied by the umbrella sensor 21 (shot voltage value:
It is also possible to measure the residual stress by measuring a) and then measuring the voltage value (unshot voltage value: Vb) of the portion that is not subjected to shots using the shaft sensor 22. In this case, the shot voltage value (Va) and the unshot voltage value (■
The rate of change (Va /Vb = r (%)) with respect to b) is determined, and the residual stress is calculated from this rate of change (r). At this time, the relationship between residual stress and rate of change is shown in FIG.
この第１６図より、残留応力と変化率とは比例的関係に
あることかわかり、これにより、個々のドライブピニオ
ン１の残留オーステナイト量の変動にも充分対応でき、
所定の疲労強度等をもつドライブピニオン１を精度よく
選別できることかわかる。From FIG. 16, it can be seen that there is a proportional relationship between the residual stress and the rate of change, and as a result, it is possible to sufficiently cope with fluctuations in the amount of retained austenite in each drive pinion 1.
It can be seen that drive pinions 1 having a predetermined fatigue strength etc. can be selected with high accuracy.
なお、上記実施例では電圧値の変化量や変化率によりド
ライブピニオンの選別を行なったか、本発明の測定方法
によれば、これらの変化量や変化率により所望の疲労強
度等を付与するショット等の加工条件の制御を行なうこ
とも可能である。In addition, in the above embodiment, drive pinions were selected based on the amount of change or rate of change in voltage value, or according to the measurement method of the present invention, a shot or the like that imparts desired fatigue strength etc. is determined based on the amount of change or rate of change in the voltage value. It is also possible to control the processing conditions.
また、上記実施例ではドライブピニオンにショットを施
した場合について残留応力を測定したか、車軸等の鋼材
についても適用可能であることは勿論である。Further, in the above embodiment, the residual stress was measured when the drive pinion was shot, but it goes without saying that the present invention can also be applied to steel materials such as axles.
［発明の効果］
以上詳述したように、本発明の鋼材の加工による残留応
力の測定方法では、残留オーステナイト組織をもつ加工
前の鋼材の透ｌａ率を検出し、しかる後に！１ｉ１１祠
の加工後にあ（プ透ｌａ率を検出し、これら検出された
加工前透磁率と加工後透磁率との変化値から残留応力を
算出するため、鋼材の加工による応力状態か等方性であ
る加工を行なった場合にも、鋼材を破壊することなく、
操作性よくかつ正確に残留応力を測定することができる
。[Effects of the Invention] As detailed above, in the method for measuring residual stress due to processing of steel materials of the present invention, the LA permeability of the steel material with retained austenite structure before processing is detected, and then! After machining the steel material, the permeability is detected and the residual stress is calculated from the change value between the detected magnetic permeability before machining and the magnetic permeability after machining. Even if a certain processing is performed, the steel material will not be destroyed,
Residual stress can be measured accurately and with good operability.
したがって、本発明の測定方法により鋼材の残留応力を
測定すれば、測定後の鋼材の使用が可能であるとともに
全数自動検査も可能になり、ひいては加工条件へのフィ
ードバック制御も可能になるため、鋼材の品質か確実に
保証される。Therefore, by measuring the residual stress of steel materials using the measurement method of the present invention, it is possible to use the steel materials after measurement, and also to perform 100% automatic inspection, which in turn makes it possible to feedback control the processing conditions. quality is guaranteed.
第１〜１１図は本発明の一実施例である測定方法１に係
り、第１図は測定装置の正面図、第２図は測定装置のブ
ロック図、第３図は測定装置の傘部センサの一部断面図
、第４図は残留応力と電圧値との関係を示すグラフ、第
５図は残留オーステナイトの減少率と残留応力との関係
を示すグラフ、第６図及び゛第７図は実施例の測定方法
の作用を示す説明図、第８図は残留オーステナイトの減
少率と電圧値との関係を示すグラフ、第９図は残留応力
と電圧値との関係を示すグラフ、第１０図はショツｌ〜
前にあける残留オーステナイト量と残留応力との関係を
示すグラフ、第１１図はアークハイトと残留応力との関
係を示すグラフである。第１２図及び第１３図は測定方
法１０利用］に係り、第１２図は工程を示す説明図、第
１３図は残留応力と電圧値との関係を示すグラフである
。第１４図及び第１５図は測定方法１の利用２に係り、
第１４図は工程を示す説明図、第１５図は残留応力と電
圧値との関係を示すグラフである。第１６図は測定方法
２に係る残留応力と変化率との関係を示すグラフである
。
１・・・ドライブピニオン（鋼材）
１１・・・傘部 １２・・・軸部２・・・測定
装置 ２１・・・傘部センサ２２・・・軸部セン
サ ２３・・・計測器特許出願人 トヨタ自動車
株式会社代理人 弁理士 大川 家
弟１図
１・・・ドライブピニオン
１］、・・・傘部
２・・・測定装置
２２・・・軸部センサ
（鋼材）
１２・・・軸部
２１・・・傘部センサ
２３・・・計測器
第３図
第６図
浸炭組成
残Ｗ山ら刀
第４図
残
式η
田
応
力
（ｋ≠圃２）
残留オ
ステナイト減少率（％）
第８図
第９図
残
留
応
力
（ｋｇ／ｍｍ ２）
第１０図
第１１図
０．４ ０．６ ０．８
アークハイト（ｍｍ）
第１６図
残
留
応
力
（ｋｇ／ｍｍ２）1 to 11 relate to measurement method 1, which is an embodiment of the present invention, in which FIG. 1 is a front view of the measuring device, FIG. 2 is a block diagram of the measuring device, and FIG. 3 is an umbrella sensor of the measuring device. Figure 4 is a graph showing the relationship between residual stress and voltage value, Figure 5 is a graph showing the relationship between residual austenite reduction rate and residual stress, Figures 6 and 7 are An explanatory diagram showing the effect of the measurement method of the example, FIG. 8 is a graph showing the relationship between the reduction rate of retained austenite and the voltage value, FIG. 9 is a graph showing the relationship between the residual stress and the voltage value, and FIG. 10 Ha shorts l~
The graph shown above is a graph showing the relationship between the amount of retained austenite and residual stress, and FIG. 11 is a graph showing the relationship between arc height and residual stress. FIG. 12 and FIG. 13 relate to the measurement method 10 used], FIG. 12 is an explanatory diagram showing the process, and FIG. 13 is a graph showing the relationship between residual stress and voltage value. 14 and 15 relate to the use 2 of measurement method 1,
FIG. 14 is an explanatory diagram showing the process, and FIG. 15 is a graph showing the relationship between residual stress and voltage value. FIG. 16 is a graph showing the relationship between residual stress and rate of change according to measurement method 2. DESCRIPTION OF SYMBOLS 1... Drive pinion (steel material) 11... Umbrella part 12... Shaft part 2... Measuring device 21... Umbrella part sensor 22... Shaft part sensor 23... Measuring instrument patent applicant Toyota Motor Corporation Agent Patent Attorney Okawa Disciple 1 Diagram 1...Drive pinion 1],... Umbrella part 2... Measuring device 22... Shaft sensor (steel material) 12... Shaft 21 ... Umbrella sensor 23 ... Measuring instrument Fig. 3 Fig. 6 Carburized composition remaining W Yamarato Fig. 4 Remaining formula η Field stress (k≠field 2) Retained austenite reduction rate (%) Fig. 8 Figure 9 Residual stress (kg/mm2) Figure 10 Figure 11 0.4 0.6 0.8 Arc height (mm) Figure 16 Residual stress (kg/mm2)
Claims (1)
磁率を検出する加工前透磁率検出工程と、該鋼材の加工
後における透磁率を検出する加工後透磁率検出工程と、 検出された加工前透磁率と加工後透磁率との変化値から
残留応力を算出する算出工程とからなることを特徴とす
る鋼材の加工による残留応力の測定方法。(1) A pre-processing magnetic permeability detection step for detecting the magnetic permeability of a steel material with a retained austenite structure before processing; a post-processing magnetic permeability detection step for detecting the magnetic permeability of the steel material after processing; and a detected pre-processing magnetic permeability detection step. A method for measuring residual stress due to processing of steel material, comprising a calculation step of calculating residual stress from a change value between magnetic permeability and post-processing magnetic permeability.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2180795A JPH0466863A (en) | 1990-07-09 | 1990-07-09 | Residual stress measuring method by steel working |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2180795A JPH0466863A (en) | 1990-07-09 | 1990-07-09 | Residual stress measuring method by steel working |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0466863A true JPH0466863A (en) | 1992-03-03 |
Family
ID=16089473
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2180795A Pending JPH0466863A (en) | 1990-07-09 | 1990-07-09 | Residual stress measuring method by steel working |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0466863A (en) |
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| KR100482523B1 (en) * | 2002-08-08 | 2005-04-14 | 현대자동차주식회사 | Analysis method of residual stress in retained austenite mixed with martensite microstruture of carburized steel alloy surface |
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