JPS6331544B2 - - Google Patents
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- Publication number
- JPS6331544B2 JPS6331544B2 JP60261188A JP26118885A JPS6331544B2 JP S6331544 B2 JPS6331544 B2 JP S6331544B2 JP 60261188 A JP60261188 A JP 60261188A JP 26118885 A JP26118885 A JP 26118885A JP S6331544 B2 JPS6331544 B2 JP S6331544B2
- Authority
- JP
- Japan
- Prior art keywords
- zirconium
- phase
- manufacturing
- based alloy
- solution treatment
- 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
Links
- 229910045601 alloy Inorganic materials 0.000 claims description 41
- 239000000956 alloy Substances 0.000 claims description 41
- 238000011282 treatment Methods 0.000 claims description 37
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 32
- 229910052726 zirconium Inorganic materials 0.000 claims description 32
- 238000004519 manufacturing process Methods 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 24
- 238000000137 annealing Methods 0.000 claims description 22
- 238000010438 heat treatment Methods 0.000 claims description 20
- 239000000446 fuel Substances 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 8
- 238000005253 cladding Methods 0.000 claims description 7
- 230000003245 working effect Effects 0.000 claims description 3
- 230000006698 induction Effects 0.000 claims description 2
- 239000003758 nuclear fuel Substances 0.000 claims description 2
- 239000003507 refrigerant Substances 0.000 claims description 2
- 125000006850 spacer group Chemical group 0.000 claims description 2
- 230000007797 corrosion Effects 0.000 description 15
- 238000005260 corrosion Methods 0.000 description 15
- 238000005242 forging Methods 0.000 description 9
- 229910001093 Zr alloy Inorganic materials 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 238000010791 quenching Methods 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 5
- 239000011651 chromium Substances 0.000 description 5
- 239000000047 product Substances 0.000 description 5
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 238000005275 alloying Methods 0.000 description 4
- 229910052804 chromium Inorganic materials 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000000171 quenching effect Effects 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 238000005096 rolling process Methods 0.000 description 3
- 229910052718 tin Inorganic materials 0.000 description 3
- 239000011135 tin Substances 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000001192 hot extrusion Methods 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000001953 recrystallisation Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
Landscapes
- Heat Treatment Of Nonferrous Metals Or Alloys (AREA)
Description
〔産業上の利用分野〕
本発明は新規なジルコニウム基合金管の製造方
法に関する。
〔従来の技術〕
ジルコニウム基合金は、その優れた耐食性と非
常に小さい中性子吸収断面積により原子力プラン
トの熱料被覆管や燃料チヤンネルボツクス等に使
用されている。これらの構造物は長期間使用され
ているため、特にその耐食性が重要である。ジル
コニウム基合金の代表的なものとして「ジルコニ
ウム―２」（ジルコニウムにスズを約1.5％、鉄を
約0.1％、クロムを0.1％、ニツケルを約0.05％添
加したもの）及び「ジルカロイ―４」（ジルコニ
ウムにスズを約1.5％、鉄を約0.2％、クロムを約
0.1％添加したもの）が知られている。
ジルコニウムは低温（862℃以下）において安
定なα相（稠密六方格子）及び高温（960℃以上）
において安定なβ相（体心立方格子）を有する。
また合金元素を添加することにより、α相からβ
相に変態を開始する温度（以下、α＋β遷移温度
と略記する。）は約30℃低下することが知られて
いる。
ジルコニウム基合金からなる燃料被覆管の従来
の製造方法を第２図に示す。
この製造工程の特徴は、高純度化、均一化のた
めの熱間押出しまでの工程と、良好な寸法と強度
じん性を得るための冷間加工工程にある。
(1) 溶解：原料のジルコニウムスポンジに所定の
合金元素（Sn、Fe、Cr、Niなど）を配合し
て、プレスにより圧縮成形して円柱状フリケツ
トを作る。これを不活性雰囲気下で溶接し電極
に仕上げ、これを消耗電極式アーク溶解炉で２
回くりかえし真空溶解してインゴツトとする。
(2) β鍛造：インゴツトをβ領域温度まで予備加
熱（通常約1000℃）し、成形のために鍛造を行
う。
(3) 溶体化処理：β鍛造後のブルームをジルコニ
ウム合金のβ領域温度まで予備加熱（通常1000
℃以上で数時間保持）後急冷（通常水冷）す
る。この溶体化処理により、偏在していた合金
元素が均一化され、金属組織は改善される。
(4) α鍛造：溶体化処理によつて生じた表面酸化
膜の除去及び寸法調整のために、700℃前後の
α領域温度範囲内で予備加熱後鍛造を行う。
(5) 機械加工、鋼被覆：α鍛造後のブルームは機
械切削および孔あけ加工して中空ビレツトにさ
れ、これに酸化、ガス吸収防止及び潤滑向上の
ために銅被覆をほどこす。
(6) 熱間押出し、：700℃近辺のα領域温度の銅被
覆ビレツトをプレスによりダイスを通して押出
し、押出し素管を作る。
(7) 中間焼鈍：焼鈍は加工による歪を除去させる
ために、通常10-4〜10-5Torrの高真空下650℃
前後で実施される。
(8) 中間圧延：室温における圧延加工により、外
径を絞り肉厚を薄くする。所定の寸法に達する
まで中間に焼鈍をはさみ数回圧延を繰返す。
(9) 最終焼鈍：通常10-4〜10-5Torrの高真空下
で、580℃前後の再結晶化焼鈍を行う。
ジルコニウム基合金より成る燃料チヤンネルボ
ツクス、燃料スペーサ等は、形状が異なるが基本
的には同様の加工方法、つまり溶解・β鍛造・溶
体化処理を行つた後、熱間塑性加工そして中間焼
なましをはさみ室温での塑性加工、最終の塑性加
工の後最終焼なましが行なわれる。
従来、熱間塑性加工温度及び焼なまし温度は、
α＋β遷移温度約830℃を越えないよう制限され
ている。この根拠は、熱間塑性加工や焼なましを
行つているときにその温度がα＋β遷移温度を越
えると、溶体化処理によつて均一化した合金元素
が熱間塑性加工や焼なまし後のゆつくりとした温
度降下によつて粗大化した析出物を作り、溶体化
処理の効果を消滅させてしまうことにある。
実際の適用温度は、前述の温度制限の範囲内で
塑性加工効率の向上、焼なまし時間の短縮など加
工作業の効率に重点が置かれて設定されている。
設定温度は、従来プロセスの記述に示したとお
り、燃料被覆管に対する再結晶化のための最終焼
なましを除き、ほぼ650〜800℃の温度領域にあ
る。
炉内で長期間中性子を照射され、同時に高温高
圧の水あるいは水蒸気にさらされているため、上
記のジルコニウム基合金においても酸化が進み、
時にはプラントの運転に重大な影響を及ぼすこと
がある。それゆえ、ジルコニウム基合金の耐食性
向上の対策が必要である。すなわち、これはプラ
ント運転の稼動低下のみならず、信頼性の低下に
もつながるからである。さらに近年、燃料棒の使
用期間延長の傾向（高燃焼度化）にともない、燃
料被覆管の耐食性に対する要求は厳しくなりつつ
ある。
ジルコニウム基合金の熱処理法として次のよう
なものがある。(1)ジルコニウム製品を（α＋β）
二相領域又はβ相領域へ急速加熱し、短時間保持
後急速冷却する特殊熱処理法（特開昭51−
110411、110412、特開昭55−100947、100967）。
(2)ジルカロイ―４板を表面部分のみβ―焼入する
方法（特開昭51−116106）。
〔発明が解決しようとする問題点〕
これらはいずれもジルコニウム合金の最終素材
又は製品状態で、高周波加熱装置又はレーザービ
ーム加熱装置等を使用して、表面部分のみβ―焼
入れ処理を施すものである。ジルコニウム合金、
特にジルカロイ合金は溶体化処理を行うことによ
りその耐食性が向上することが知られている。こ
れらの熱処理は板材や製品の最終形状の状態で行
い、表面部分のみ焼入れ処理を行うため高周波加
熱装置で行われている。しかし、これらの最終形
状での加熱、冷却工程の制御が困難な外に、表面
部分の酸化現象や熱応力による変形及び残留応力
の問題が生じる。これらの問題のために、β―焼
入れ後酸化皮膜の除去や変形の矯正等をしなけれ
ばならない。
本発明の目的は、上記の事情に鑑みて、後述す
る新しい知見にもとづき、従来の最終熱間加工後
の溶体化処理を施さないものの機械的性質と同等
で、耐食性がそれより優れ、かつ熱処理による変
形の少ないジルコニウム基合金管の製造法を提供
するにある。
〔問題点を解決するための手段〕
本発明は、最終熱間塑性加工後のジルコニウム
基合金管に複数回の冷間塑性加工と中間焼なまし
処理を施す製造方法において、前記合金管を前記
最終熱間塑性加工後で、且つ最初の冷間塑性加工
前に、前記合金のα相およびβ相を含む温度領
域、又は前記合金のβ相温度領域に高周波誘導コ
イル内を通過させることによつて加熱し、前記コ
イルの通過直後に前記合金管の外表面の冷媒によ
つて強制的に急冷する溶体化処理を施すことを特
徴とするジルコニウム基合金管の製造法にある。
従来の製造工程は第２図に示すようにインゴツ
トを熱間加工した後に溶体化処理が行われてい
る。この溶体化処理によりマトリツクスに固溶し
た金属間化合物（例えば、ZrCr2やZrxFe5Cr2な
ど）は、その後の熱間加工又は温間加工により析
出が促進される。析出して、粗大化した金属間化
合物は耐食性を劣化させる。
〔作用〕
本発明法では溶体化処理の効果を最終の素材ま
で失なわれないようにするため、最終の熱間加工
又は温間加工の後で、最初の冷間塑性加工の前に
第１の溶体化処理を施すものである。熱間加工や
温間加工による析出の促進を防止する。第１図に
本発明法による製造工程を示す。β―鍛造後のα
―鍛造は場合によつては省略しても良い。α鍛造
は単なる寸法整形のための工程である。
本発明の製造法は最終熱間加工したジルコニウ
ム基合金管を最初の冷間塑性加工前に高周波コイ
ルを通過させることによつてα＋β相又はβ相温
度領域に連続的に加熱し、急冷した後、焼なまし
を入れて少なくとも２回の冷間塑性加工を施すこ
とによつて最終熱間加工後に従来の焼入を施さな
いものの機械的性質と同等の特性、特に伸び率が
高いものが得られるとともにそれより耐食性の高
いノジユラー腐食を生じないものを得ることがで
きる。この高周波コイルの通過による加熱は特に
最終熱間塑性加工後の素管の厚肉に対して行うの
で、管内外の温度に対して温度差が生じるが、そ
の外面は内面より温度が高くなる。その温度差は
投入電力、その通過速度によつて変えることがで
きる。そのため内面の温度をあまり高くせずに外
面をα＋β相又はβ相温度領域に加熱でき、外面
を焼入れすることができる。この内外の温度差は
厚肉の段階で高周波加熱することによつて容易に
得られるとともに、その加熱厚さは周波数の調整
によつてコントロールすることができる。また、
加熱後の冷却は管の内・外面に温水又は冷水を吹
きつけることによつて行うことができる。
第１の溶体化処理は最終熱間加工後、その温度
からβ相又はα＋β相へ加熱して（室温まで冷却
せずに）実施することも効果がある。更に、この
ようなβ相での溶体化処理後に更に（α＋β）相
へ加熱して急冷するという不完全溶体化処理を実
施することも効果がある。すなわち、β相加熱に
よつて結晶粒が粗大した場合などはその後（α＋
β）相へ加熱し冷却することによつて、更に組織
の改善が行なわれる。
第２の溶体化処理を施さずに第１の溶体化処理
としてβ相の温度領域で行う方が耐食性が向上し
好ましい。
第２の溶体化処理を施す場合には、第１の溶体
化処理はα相とβ相の混合温度領域で行うのが好
ましい。
本発明によつて製造されたジルコニウム基合金
管のミクロ組織は従来のものより改善され、その
結果耐食性が著しく向上した。
実施例 １
素材はジルカロイ―２合金である。その主な化
学成分は1.5wt％Sn―0.136wt％Fe―0.097wt％Cr
―0.056wt％Ni、残Zrである。第２図に示す製造
工程において、熱間加工後の材料の一部を再び溶
体化処理を施した。その後の製造工程は両者とも
同じである。本発明は最初の冷間塑性加工前の最
終熱間加工後の外径63.5mm、肉厚10.9mmの押出し
素管を高周波コイルを約10秒以内の保持で通過さ
せることによつて外面温度で1020〜1050℃のβ
相、870〜930℃のα＋β相に加熱後、高周波コイ
ルの通過直後に水を噴霧して冷却する溶体化処理
をしたものである。更に、中間焼なましを600℃、
最終焼なましを580℃で行ない、３回の冷間塑性
加工を施した。従来法は溶体化処理を施さず、中
間焼なましを650℃で行う他は本発明と同じであ
る。第１表は従来法、本発明法（α＋β相、β相
焼入）の製造工程を示したものである。なお、従
来法及びβ相焼入れしたものはジルカロイ―２合
金を用い、α＋β相焼入れはジルカロイ―４合金
（Sn1.5wt％、Fe0.21wt％、Cr0.10wt％、残Zr）
を用いた。
[Industrial Application Field] The present invention relates to a novel method for manufacturing a zirconium-based alloy tube. [Prior Art] Zirconium-based alloys are used for heating material cladding tubes, fuel channel boxes, etc. of nuclear power plants because of their excellent corrosion resistance and extremely small neutron absorption cross section. Since these structures are used for long periods of time, their corrosion resistance is especially important. Typical zirconium-based alloys include "Zirconium-2" (zirconium with approximately 1.5% tin, approximately 0.1% iron, 0.1% chromium, and approximately 0.05% nickel added) and "Zircaloy-4" ( Zirconium contains approximately 1.5% tin, approximately 0.2% iron, and approximately chromium.
0.1% added) is known. Zirconium has a stable α phase (close-packed hexagonal lattice) at low temperatures (below 862℃) and a stable alpha phase (close-packed hexagonal lattice) at high temperatures (above 960℃).
It has a stable β phase (body-centered cubic lattice).
In addition, by adding alloying elements, it is possible to change the α phase to β phase.
It is known that the temperature at which phase transformation starts (hereinafter abbreviated as α+β transition temperature) decreases by about 30°C. FIG. 2 shows a conventional manufacturing method for a fuel cladding tube made of a zirconium-based alloy. This manufacturing process is characterized by hot extrusion for high purity and uniformity, and cold working for obtaining good dimensions and strength and toughness. (1) Melting: Mix the specified alloying elements (Sn, Fe, Cr, Ni, etc.) with the raw zirconium sponge and press it to form a cylindrical friket. This is welded into an electrode in an inert atmosphere, and then melted in a consumable electrode type arc melting furnace.
It is repeatedly vacuum melted and made into an ingot. (2) β-forging: The ingot is preheated to β-region temperature (usually about 1000℃) and then forged for forming. (3) Solution treatment: Preheating the bloom after β forging to the β region temperature of the zirconium alloy (usually 1000
℃ or higher for several hours) and then rapidly cooled (usually water-cooled). This solution treatment homogenizes the unevenly distributed alloying elements and improves the metal structure. (4) α forging: To remove the surface oxide film caused by solution treatment and adjust dimensions, forging is performed after preheating within the α region temperature range of around 700°C. (5) Machining and steel coating: After alpha forging, the bloom is machined and drilled into a hollow billet, which is coated with copper to prevent oxidation and gas absorption and improve lubrication. (6) Hot extrusion: A copper-coated billet at α region temperature of around 700°C is extruded through a die using a press to make an extruded raw tube. (7) Intermediate annealing: Annealing is usually performed at 650℃ under a high vacuum of 10 -4 to 10 -5 Torr to remove distortion caused by processing.
It is carried out before and after. (8) Intermediate rolling: Rolling at room temperature reduces the outer diameter and wall thickness. Rolling is repeated several times with annealing in between until the predetermined dimensions are reached. (9) Final annealing: Recrystallization annealing is usually performed at around 580°C under a high vacuum of 10 -4 to 10 -5 Torr. Fuel channel boxes, fuel spacers, etc. made of zirconium-based alloys have different shapes, but are basically processed using the same processing methods: melting, β-forging, and solution treatment, followed by hot plastic working and intermediate annealing. After the final plastic working, final annealing is performed at room temperature. Conventionally, hot plastic working temperature and annealing temperature are
It is limited to not exceed the α+β transition temperature of approximately 830°C. The basis for this is that if the temperature exceeds the α+β transition temperature during hot plastic working or annealing, the alloying elements homogenized by solution treatment will be removed after hot plastic working or annealing. The slow temperature drop produces coarse precipitates, which eliminates the effect of solution treatment. The actual applicable temperature is set within the above-mentioned temperature limits with emphasis on efficiency of processing operations, such as improving plastic working efficiency and shortening annealing time.
As shown in the description of the conventional process, the set temperature is approximately in the temperature range of 650 to 800° C., except for the final annealing for recrystallization of the fuel cladding. Because it is irradiated with neutrons for a long period of time in the furnace and is exposed to high temperature and high pressure water or steam, oxidation progresses even in the above-mentioned zirconium-based alloy.
Sometimes this can have a significant impact on plant operation. Therefore, measures are needed to improve the corrosion resistance of zirconium-based alloys. In other words, this leads not only to a decrease in plant operation efficiency but also to a decrease in reliability. Furthermore, in recent years, with the trend of extending the service life of fuel rods (increasing burnup), requirements for corrosion resistance of fuel cladding tubes are becoming stricter. There are the following heat treatment methods for zirconium-based alloys. (1) Zirconium products (α+β)
A special heat treatment method that rapidly heats the two-phase region or β-phase region, holds it for a short period of time, and then rapidly cools it.
110411, 110412, Japanese Unexamined Patent Publication No. 55-100947, 100967).
(2) A method in which only the surface portion of Zircaloy-4 plate is β-quenched (Japanese Patent Application Laid-Open No. 116106/1983). [Problems to be solved by the invention] All of these are zirconium alloys in the final raw material or product state, and only the surface portion is subjected to β-quenching treatment using a high frequency heating device, a laser beam heating device, etc. . zirconium alloy,
In particular, it is known that the corrosion resistance of Zircaloy alloys is improved by solution treatment. These heat treatments are performed on the final shape of the plate material or product, and are performed using a high-frequency heating device to harden only the surface portion. However, it is difficult to control the heating and cooling processes in these final shapes, and problems arise such as deformation and residual stress due to oxidation of the surface portion and thermal stress. Because of these problems, it is necessary to remove the oxide film and correct deformation after β-quenching. In view of the above-mentioned circumstances, and based on the new knowledge described below, the object of the present invention is to provide a material that has mechanical properties equivalent to and superior in corrosion resistance to conventional products that are not subjected to solution treatment after final hot working, and that is heat treated. An object of the present invention is to provide a method for manufacturing a zirconium-based alloy tube that causes less deformation. [Means for Solving the Problems] The present invention provides a manufacturing method in which a zirconium-based alloy tube after final hot plastic working is subjected to a plurality of cold plastic workings and intermediate annealing treatment. After the final hot plastic working and before the first cold plastic working, the alloy is passed through a high-frequency induction coil into a temperature region containing the α phase and β phase, or into the β phase temperature region of the alloy. The method for manufacturing a zirconium-based alloy tube is characterized in that a solution treatment is performed by heating the tube through a coil, and immediately after passing through the coil, the tube is subjected to a solution treatment in which the outer surface of the tube is forcibly cooled down by a refrigerant. In the conventional manufacturing process, as shown in FIG. 2, an ingot is hot worked and then subjected to solution treatment. Intermetallic compounds (for example, ZrCr 2 and ZrxFe 5 Cr 2 ) dissolved in the matrix by this solution treatment are promoted to precipitate by subsequent hot working or warm working. Intermetallic compounds that precipitate and become coarse deteriorate corrosion resistance. [Operation] In the method of the present invention, in order to prevent the effect of solution treatment from being lost to the final material, the first step is performed after the final hot working or warm working and before the first cold plastic working. It is subjected to solution treatment. Prevents the promotion of precipitation due to hot working or warm working. FIG. 1 shows the manufacturing process according to the method of the present invention. β - α after forging
-Forging may be omitted in some cases. α forging is simply a process for dimensional shaping. The manufacturing method of the present invention involves continuously heating the final hot worked zirconium-based alloy tube to the α+β phase or β phase temperature region by passing it through a high-frequency coil before the first cold plastic working, and then rapidly cooling it. By performing cold plastic working at least twice with annealing, it is possible to obtain mechanical properties equivalent to those without conventional quenching after the final hot working, especially those with high elongation. At the same time, it is possible to obtain a product that has higher corrosion resistance and does not cause nodular corrosion. Since heating by passing through the high-frequency coil is performed particularly on the thick wall of the raw tube after the final hot plastic working, a temperature difference occurs between the inside and outside of the tube, and the temperature of the outer surface is higher than that of the inner surface. The temperature difference can be changed depending on the input power and its passing speed. Therefore, the outer surface can be heated to the α+β phase or β phase temperature range without increasing the temperature of the inner surface too much, and the outer surface can be hardened. This temperature difference between the inside and outside can be easily obtained by high-frequency heating at the thick stage, and the heating thickness can be controlled by adjusting the frequency. Also,
Cooling after heating can be performed by spraying hot or cold water onto the inner and outer surfaces of the tube. It is also effective to carry out the first solution treatment after the final hot working by heating from that temperature to the β phase or α+β phase (without cooling to room temperature). Furthermore, it is also effective to carry out an incomplete solution treatment in which the solution treatment in the β phase is further heated to the (α+β) phase and then rapidly cooled. In other words, if the crystal grains become coarse due to β-phase heating, then (α+
The structure is further improved by heating to β) phase and cooling. It is preferable to perform the first solution treatment in the β phase temperature range without performing the second solution treatment because corrosion resistance is improved. When performing the second solution treatment, the first solution treatment is preferably performed in the temperature range where the α phase and β phase are mixed. The microstructure of the zirconium-based alloy tube produced according to the present invention is improved over that of conventional tubes, resulting in significantly improved corrosion resistance. Example 1 The material is Zircaloy-2 alloy. Its main chemical components are 1.5wt%Sn-0.136wt%Fe-0.097wt%Cr
-0.056wt%Ni, balance Zr. In the manufacturing process shown in FIG. 2, part of the material after hot working was subjected to solution treatment again. The subsequent manufacturing process is the same for both. In the present invention, an extruded raw tube with an outer diameter of 63.5 mm and a wall thickness of 10.9 mm after the final hot working before the first cold plastic working is passed through a high-frequency coil for less than about 10 seconds to maintain the outer surface temperature. β of 1020~1050℃
After heating to α+β phase at 870 to 930°C, solution treatment is performed by spraying water and cooling immediately after passing through a high-frequency coil. Furthermore, intermediate annealing is performed at 600℃.
Final annealing was performed at 580°C and cold plastic working was performed three times. The conventional method is the same as the present invention except that no solution treatment is performed and intermediate annealing is performed at 650°C. Table 1 shows the manufacturing process of the conventional method and the method of the present invention (α+β phase, β phase quenching). In addition, Zircaloy-2 alloy was used for conventional method and β-phase quenching, and Zircaloy-4 alloy was used for α+β phase quenching (Sn1.5wt%, Fe0.21wt%, Cr0.10wt%, residual Zr).
was used.
【表】
これら両者のジルカロイ管を用いて腐食試験を
行つた。腐食試験は500℃、105Kg／cm2高温高圧水
蒸気中で50h保持し、試験終了後、試験片の外観
観察により両者の状態を比較した。その結果を第
２表に示す。[Table] Corrosion tests were conducted using both of these Zircaloy tubes. The corrosion test was carried out at 500°C in 105 kg/cm 2 high temperature and high pressure steam for 50 hours, and after the test, the appearance of the test piece was observed and the conditions of the two were compared. The results are shown in Table 2.
以上本発明によればジルコニウム基合金、特に
ジルカロイ基合金管の耐食性を向上できるので、
特に原子炉用燃料被覆管の寿命が顕著に向上す
る。
As described above, according to the present invention, the corrosion resistance of zirconium-based alloys, especially zircaloy-based alloy pipes, can be improved.
In particular, the life of fuel cladding tubes for nuclear reactors is significantly improved.
第１図は本発明法のジルコニウム基合金の製造
工程のフロー図、第２図はジルカロイ原子炉燃料
棒被覆管の従来の製造工程を示すフロー図、第３
図は従来法及び本発明法による機械的性質を示す
図、及び第４図は本発明法による焼なまし温度と
腐食増量との関係を示す線図である。
Fig. 1 is a flow diagram of the manufacturing process of a zirconium-based alloy according to the present invention, Fig. 2 is a flow diagram showing the conventional manufacturing process of Zircaloy nuclear reactor fuel rod cladding tube, and Fig. 3
The figure is a diagram showing mechanical properties according to the conventional method and the method of the present invention, and FIG. 4 is a diagram showing the relationship between annealing temperature and corrosion weight increase according to the method of the present invention.
Claims (1)
に複数回の冷間塑性加工と該冷間塑性加工間の中
間焼なまし処理を施す製造方法において、 前記合金管を前記最終熱間塑性加工後で、且つ
最初の冷間塑性加工前に、 前記合金のα相およびβ相を含む温度領域、又
は前記合金のβ相温度領域に高周波誘導コイル内
を通過させることによつて加熱し、前記コイルの
通過直後に前記合金管の外表面を冷媒によつて強
制的に急冷する溶体化処理を施すことを特徴とす
るジルコニウム基合金管の製造法。 ２ 前記冷間塑性加工及び前記焼なまし処理を３
回以上施す特許請求の範囲第１項に記載のジルコ
ニウム基合金管の製造法。 ３ 前記焼なまし処理を640℃以下の温度で行う
特許請求の範囲第１項又は第２項に記載のジルコ
ニウム基合金管の製造法。 ４ 前記合金のβ相の温度領域で加熱し急冷する
第２の溶体化処理後、前記最終熱間塑性加工を施
し、次いで前記合金のβ相又はα相とβ相を含む
温度領域で加熱し急冷する第１の溶体化処理を施
す特許請求の範囲第１項〜第３項のいずれかに記
載のジルコニウム基合金管の製造法。 ５ 前記第２の溶体化処理を施すことなく前記最
終熱間塑性加工を施し、次いで前記β相の温度領
域で加熱し急冷する前記第１の溶体化処理を施す
特許請求の範囲第１項〜第３項のいずれかに記載
のジルコニウム基合金管の製造法。 ６ 前記最終熱間塑性加工後、その温度より前記
第１の溶体化処理を施す特許請求の範囲第１項〜
第５項のいずれかに記載のジルコニウム基合金管
の製造法。 ７ 前記第１の溶体化処理後、前記α相とβ相の
温度領域で加熱し急冷する特許請求の範囲第５項
又は第６項に記載のジルコニウム基合金管の製造
法。 ８ 最終の冷間塑性加工後の焼なまし処理を400
〜550℃以下の温度で行う特許請求の範囲第１項
〜第７項のいずれかに記載のジルコニウム基合金
管の製造法。 ９ 前記合金によつて原子炉用部材を構成した特
許請求の範囲第１項〜第８項のいずれかに記載の
ジルコニウム基合金管の製造法。 １０ 前記合金によつて原子炉用燃料棒被覆管、
燃料チヤンネルボツクス、燃料スペーサ、燃料バ
ンドルの少なくとも１つを構成した特許請求の範
囲第１項〜第９項のいずれかに記載のジルコニウ
ム基合金管の製造法。[Scope of Claims] 1. A manufacturing method in which a zirconium-based alloy tube after final hot plastic working is subjected to a plurality of cold plastic workings and an intermediate annealing treatment between the cold plastic workings, comprising: After the final hot plastic working and before the first cold plastic working, by passing through a high frequency induction coil into a temperature region containing the α phase and β phase of the alloy, or a β phase temperature region of the alloy. 2. A method for manufacturing a zirconium-based alloy tube, comprising: heating the tube with a zirconium-based alloy tube, and immediately after passing through the coil, performing a solution treatment in which the outer surface of the alloy tube is forcibly quenched with a refrigerant. 2 The cold plastic working and the annealing treatment are performed in 3
A method for manufacturing a zirconium-based alloy tube according to claim 1, which is performed more than once. 3. The method for manufacturing a zirconium-based alloy tube according to claim 1 or 2, wherein the annealing treatment is performed at a temperature of 640° C. or lower. 4 After the second solution treatment in which the alloy is heated in the temperature range of the β phase and rapidly cooled, the final hot plastic working is performed, and then the alloy is heated in a temperature range that includes the β phase or the α phase and the β phase. The method for manufacturing a zirconium-based alloy tube according to any one of claims 1 to 3, wherein the first solution treatment is performed by rapid cooling. 5. The final hot plastic working is performed without performing the second solution treatment, and then the first solution treatment is performed by heating in the temperature region of the β phase and rapidly cooling. The method for manufacturing a zirconium-based alloy tube according to any one of Item 3. 6. After the final hot plastic working, the first solution treatment is performed at that temperature.
A method for manufacturing a zirconium-based alloy tube according to any one of Item 5. 7. The method for manufacturing a zirconium-based alloy tube according to claim 5 or 6, wherein after the first solution treatment, the tube is heated in the temperature range of the α phase and β phase and then rapidly cooled. 8 Annealing treatment after final cold plastic working
A method for manufacturing a zirconium-based alloy tube according to any one of claims 1 to 7, which is carried out at a temperature of ~550°C or less. 9. The method for manufacturing a zirconium-based alloy tube according to any one of claims 1 to 8, wherein a nuclear reactor member is made of the alloy. 10 A nuclear reactor fuel rod cladding tube made of the above alloy,
A method for manufacturing a zirconium-based alloy tube according to any one of claims 1 to 9, which constitutes at least one of a fuel channel box, a fuel spacer, and a fuel bundle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26118885A JPS61143572A (en) | 1985-11-22 | 1985-11-22 | Manufacture of zirconium alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26118885A JPS61143572A (en) | 1985-11-22 | 1985-11-22 | Manufacture of zirconium alloy |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11973981A Division JPS5822364A (en) | 1981-07-29 | 1981-07-29 | Preparation of zirconium base alloy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61143572A JPS61143572A (en) | 1986-07-01 |
| JPS6331544B2 true JPS6331544B2 (en) | 1988-06-24 |
Family
ID=17358357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26118885A Granted JPS61143572A (en) | 1985-11-22 | 1985-11-22 | Manufacture of zirconium alloy |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61143572A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56119739A (en) * | 1980-02-28 | 1981-09-19 | Nisshin Steel Co Ltd | Manufacture of high-strength steel strip |
| JPS59226158A (en) * | 1983-06-06 | 1984-12-19 | Hitachi Ltd | Manufacture of fuel structural member with high corrosion resistance |
-
1985
- 1985-11-22 JP JP26118885A patent/JPS61143572A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56119739A (en) * | 1980-02-28 | 1981-09-19 | Nisshin Steel Co Ltd | Manufacture of high-strength steel strip |
| JPS59226158A (en) * | 1983-06-06 | 1984-12-19 | Hitachi Ltd | Manufacture of fuel structural member with high corrosion resistance |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61143572A (en) | 1986-07-01 |
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