JPH0354007B2 - - Google Patents
Info
- Publication number
- JPH0354007B2 JPH0354007B2 JP60065845A JP6584585A JPH0354007B2 JP H0354007 B2 JPH0354007 B2 JP H0354007B2 JP 60065845 A JP60065845 A JP 60065845A JP 6584585 A JP6584585 A JP 6584585A JP H0354007 B2 JPH0354007 B2 JP H0354007B2
- Authority
- JP
- Japan
- Prior art keywords
- steel
- stainless steel
- austenitic stainless
- thickness
- cracks
- 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 - Lifetime
Links
- 229910000831 Steel Inorganic materials 0.000 claims description 64
- 239000010959 steel Substances 0.000 claims description 64
- 239000000463 material Substances 0.000 claims description 61
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 45
- 229910000963 austenitic stainless steel Inorganic materials 0.000 claims description 28
- 229910052742 iron Inorganic materials 0.000 claims description 20
- 238000005098 hot rolling Methods 0.000 claims description 15
- 238000003466 welding Methods 0.000 claims description 9
- 238000005096 rolling process Methods 0.000 claims description 8
- 238000005242 forging Methods 0.000 claims description 4
- 229910001220 stainless steel Inorganic materials 0.000 description 17
- 239000010935 stainless steel Substances 0.000 description 15
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 230000007797 corrosion Effects 0.000 description 8
- 238000005260 corrosion Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 238000012545 processing Methods 0.000 description 8
- 239000000047 product Substances 0.000 description 8
- 238000004519 manufacturing process Methods 0.000 description 7
- 229910001566 austenite Inorganic materials 0.000 description 5
- 238000005336 cracking Methods 0.000 description 5
- 239000003758 nuclear fuel Substances 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 4
- 229910000975 Carbon steel Inorganic materials 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 239000010962 carbon steel Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 239000002915 spent fuel radioactive waste Substances 0.000 description 3
- 241000251468 Actinopterygii Species 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 238000010301 surface-oxidation reaction Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 241000316887 Saissetia oleae Species 0.000 description 1
- 241000270666 Testudines Species 0.000 description 1
- 241000270708 Testudinidae Species 0.000 description 1
- 208000009205 Tinnitus Diseases 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 230000003009 desulfurizing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000009497 press forging Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
この発明は、核燃料集合体輸送用容器、核燃料
保管用ラツク及び使用済み核燃料保管用ラツク等
に用いられるB00.5wt％〜3.0wt％含有の
Cr15wt％〜24wt％−Ni6wt％〜17wt％系オース
テナイトステンレス鋼の製造方法に係り、特に、
熱間圧延性の改善を目的としたＢ含有オーステナ
イトステンレス鋼の製造方法に関する。[Detailed Description of the Invention] Industrial Application Field This invention is applicable to containers for transporting nuclear fuel assemblies, racks for storing nuclear fuel, racks for storing spent nuclear fuel, etc. containing 0.5wt% to 3.0wt% of B0 and 15wt% of Cr. Regarding the manufacturing method of ~24wt%-Ni6wt%~17wt% austenitic stainless steel, in particular,
The present invention relates to a method for producing B-containing austenitic stainless steel for the purpose of improving hot rolling properties.
従来の技術
一般に、Ｂ含有オーステナイトステンレス鋼
は、含有するＢの中性子吸収断面積が大きいこと
より、中性子の制御材及び遮蔽材として用いられ
ている。BACKGROUND OF THE INVENTION In general, B-containing austenitic stainless steels are used as neutron control and shielding materials because the B they contain has a large neutron absorption cross section.
特に、高Ｂ含有オーステナイトステンレス鋼
は、核燃料集合体輸送用容器、核燃料保管用ラツ
ク及び使用済み核燃料保管用ラツク等に用いられ
ているが、今日、該容器やラツクの小形化と低コ
スト化のために、素材である該ステンレス鋼の薄
肉化が要望されている。 In particular, high B-containing austenitic stainless steel is used for containers for transporting nuclear fuel assemblies, racks for storing nuclear fuel, racks for storing spent nuclear fuel, etc., and today, these containers and racks are becoming smaller and lower in cost. Therefore, there is a demand for thinner stainless steel material.
しかし、Ｂ含有のオーステナイトステンレス鋼
は、Ｂ含有量が多くなると、Ｂがステンレス鋼に
固溶せず、硼化物が析出し、これが脆い性質を有
するため、熱間加工時に割れ易く、また一旦割れ
が生じると硼化物によつて、割れが伝播し、割れ
が少なく加工できる熱間加工温度領域が狭く、難
加工材となり、熱間圧延時に圧延材の表面、特に
冷却され易く引張力の掛る長手方向の縁部に、割
れやひび疵などが発生し易くなり、後工程での加
工が不可能となつて製品化できず、歩留が悪い問
題があつた。 However, when B-containing austenitic stainless steel has a high B content, B does not dissolve solidly in the stainless steel and precipitates boride, which has brittle properties, making it susceptible to cracking during hot working, and once cracked. When this occurs, cracks propagate due to borides, and the hot working temperature range that can be worked with few cracks is narrow, making the material difficult to work. Cracks and cracks are more likely to occur on the edges, making post-processing impossible, making it impossible to commercialize the product, and resulting in poor yields.
発明が解決しようとする課題
このため、従来、熱間圧延性改善について、
種々検討（特開昭56−38418号、特開昭54−6842
号）されているが、前記の公知技術は、鋼材、
Fe−Ni合金あるいはTi材の熱間圧延において、
前記素材の外周全面を薄鉄板で被包して熱間圧延
したり、有孔異種金属板で被包して熱間圧延する
技術であるが、これは酸化防止及び焼付き防止の
ためであり、本発明鋼のごとき硼化物とオーステ
ナイト相との２相よりなる合金の難加工性を改善
するものではなかつた。Problems to be Solved by the Invention For this reason, conventionally, regarding hot rolling property improvement,
Various studies (JP-A-56-38418, JP-A-54-6842)
However, the above-mentioned known technology is based on steel materials,
In hot rolling of Fe-Ni alloy or Ti material,
This is a technique in which the entire outer periphery of the material is covered with a thin iron plate and hot rolled, or covered with a perforated dissimilar metal plate and hot rolled, but this is to prevent oxidation and seizure. However, it did not improve the difficult-to-work properties of an alloy consisting of two phases, boride and austenite, such as the steel of the present invention.
この発明は、Ｂ含有のオーステナイトステンレ
ス鋼の熱間加工性の改善を目的とし、熱間加工時
に加工材の長手方向縁部に割れやひび疵が発生す
るのを防止し、後続工程の加工を容易にし、製品
歩留の大幅な向上が得られるＢ含有オーステナイ
トステンレス鋼の製造方法を目的としている。 The purpose of this invention is to improve the hot workability of B-containing austenitic stainless steel, by preventing the occurrence of cracks and cracks on the longitudinal edges of the workpiece during hot working, and by preventing the formation of cracks in the longitudinal edges of the workpiece during hot working. The object of the present invention is to provide a method for manufacturing B-containing austenitic stainless steel that is easy and can significantly improve product yield.
課題を解決するための手段
この発明は、
B0.5wt％〜3.0wt％含有のCr15wt％〜24wt％
−Ni6wt％〜17wt％系オーステナイトステンレ
ス鋼素材の少なくとも４主面を鉄筒にて密着包囲
し、分塊圧延あるいは鍛造し、
該素材表面の鉄層を除去したのち、該素材の厚
み側両側面に、１側面を面取加工した厚みが該素
材厚みより１mm〜10mm厚い鋼条片を密着させ、
該素材と鋼条片との間に形成される凹部に、オ
ーステナイトステンレス鋼にて該素材より
１mm〜10mm厚い肉盛溶接した後、
950℃〜1250℃に加熱し、１パス当りの圧下率10
％〜70％で、少なくとも１回の熱間圧延を行つた
後、外表面の鋼条片層及びオーステナイトステン
レス鋼層部分を除去することを特徴とするＢ含有
オーステナイトステンレス鋼の製造方法である。Means for Solving the Problems This invention provides B0.5wt% to 3.0wt% containing Cr15wt% to 24wt%.
- Closely surround at least four main surfaces of a Ni6wt% to 17wt% austenitic stainless steel material with iron cylinders, bloom-roll or forge it, remove the iron layer on the surface of the material, and then process both thick sides of the material. A steel strip with one side chamfered and having a thickness of 1 mm to 10 mm thicker than the material is brought into close contact with the material, and austenitic stainless steel is placed in the recess formed between the material and the steel strip. After overlay welding 1mm to 10mm thick, heat to 950℃ to 1250℃ and reduce the reduction rate to 10 per pass.
% to 70%, and then hot rolling is performed at least once, and then the steel strip layer and the austenitic stainless steel layer portion on the outer surface are removed.
作 用
工 程
さらに、詳述すれば、この発明は、
ａ B0.5wt％〜3.0wt％含有のCr15wt％〜24wt
％−Ni6wt％〜17wt％系オーステナイトステ
ンレス鋼塊を、
ｂ 例えば、型抜き用勾配のついた鋳塊、あるい
は連続鋳造によるスラブ鋳片またはビレツト鋳
片を所要寸法に切断整形し、
得られた鋼素材の少なくとも４主面、すなわ
ち、長手方向の両端面を除く上下面と両側面の
４主面の黒皮を除去し、清浄化し、
ｃ この４主面を、炭素鋼あるいはステンレス鋼
からなるパイプや板による溶接組立体などの鉄
筒にて密着包囲し、
b′ あるいは、鋳型内の内壁に密着させて嵌入
した、炭素鋼あるいはステンレス鋼からなる
鉄筒内に、前記オーステナイトステンレス鋼
の溶鋼を鋳込み、
c′ 得られた鋼素材の少なくとも４主面、すな
わち、長手方向の両端面を除く上下面と両側
面の４主面に送素鋼やステンレス鋼からなる
鉄筒を密着させた鋼塊に造塊し、
ｄ 上記ｃまたはc′の鋼素材を950℃〜1250℃に
て分塊圧延あるいは鍛造し、
ｅ さらに、上記素材表面の鉄層を除去し、
ｆ 第１図に示す如く、鋼素材１の四隅に面取２
加工を行ない、炭素鋼あるいはステンレス鋼か
らなる該鋼素材より特定の肉厚の鋼条片３の一
方側面の面取４加工を行ない、鋼素材１の両側
面にそれぞれ鋼条片３を面取側で突合せ、両者
間の面取２，４部で構成される凹部に、ステン
レス鋼にて該鋼素材より特定肉厚の肉盛５溶接
し、
ｇ 950℃〜1250℃に加熱し、１パス当りの圧下
率10％〜70％で、少なくとも１回の熱間圧延を
行なつたのち、
ｈ 板材の外表面の鋼条片層及びステンレス鋼層
部分を切削除去し、
ｉ そのままか、あるいは溶体化処理を施し、必
要に応じて冷間圧延もしくはレベラーにより平
坦度を矯正し、
熱間圧延時に圧延材の長手方向縁部に割れや
ひび疵のない品質良好な高Ｂ含有オーステナイ
トステンレス鋼を歩留よく得る製造方法であ
る。Working process Further, to be more detailed, the present invention includes a Cr containing 15 wt% to 24 wt% of B0.5 wt% to 3.0 wt%.
%-Ni6wt% to 17wt% series austenitic stainless steel ingot, b For example, an ingot with a slope for mold cutting, or a slab or billet slab by continuous casting is cut and shaped to the required dimensions, and the obtained steel is At least four principal surfaces of the material, i.e., the top and bottom surfaces and both side surfaces excluding both end surfaces in the longitudinal direction, are removed and cleaned, and c. The molten steel of the austenitic stainless steel is placed in an iron cylinder made of carbon steel or stainless steel, which is tightly surrounded by an iron cylinder such as a welded assembly made of steel or plates, or is fitted tightly into the inner wall of the mold. Casting, c' A steel ingot made of iron tubes made of feed steel or stainless steel that are tightly attached to at least four main surfaces of the obtained steel material, i.e., the top and bottom surfaces and both side surfaces excluding both end surfaces in the longitudinal direction. d) The steel material c or c' above is bloomed or forged at 950°C to 1250°C, e) Further, the iron layer on the surface of the material is removed, f as shown in Figure 1. Chamfer 2 on the four corners of steel material 1
Processing is performed to chamfer 4 one side of a steel strip 3 of a specific thickness from the steel material made of carbon steel or stainless steel, and chamfer the steel strip 3 on both sides of the steel material 1. Butt the sides, and weld a specific wall thickness of stainless steel to the concave part made up of the chamfers 2 and 4 between the two, heat it to 950℃ to 1250℃, and perform one pass. After hot rolling at least once at a rolling reduction rate of 10% to 70%, h) the steel strip layer and the stainless steel layer on the outer surface of the plate material are cut and removed; The flatness is corrected by cold rolling or a leveler as necessary, and high quality high B-containing austenitic stainless steel with no cracks or cracks on the longitudinal edges of the rolled material is produced during hot rolling. It is a manufacturing method that can be obtained with high yield.
この発明において、上記ｃ、c′の鉄筒は、パイ
プ状や板材による溶接組立体などが利用でき、ｃ
については鋼素材の４主面を包囲するほか、全面
を完全被包することも、鋼塊の加工時の温度降下
防止に有効であり、c′については鉄筒内に鋳込が
可能であればよく、鋳込時に底付き鉄筒でもよ
く、また、密着の度合は、溶着するほうが好まし
いが、完全に溶着する必要はなく、熱間圧延前に
鉄筒を除去するため、分塊圧延または鍛造の間、
該素材を保護できる程度に密着すればよい。 In this invention, the above iron cylinders c and c' can be in the form of a pipe or a welded assembly made of plate materials, and c
For c', in addition to surrounding the four main surfaces of the steel material, completely encasing the entire surface is also effective in preventing temperature drop during processing of the steel ingot, and for c', it is possible to cast it into a steel cylinder. If possible, a steel tube with a bottom may be used at the time of casting.Also, it is preferable to weld the degree of adhesion, but it is not necessary to completely weld.In order to remove the steel tube before hot rolling, welding is preferable. During forging,
It is sufficient that the material is in close contact with the material to the extent that it can be protected.
また、ｂにおいて、鉄筒に装入する前の手入
は、完全に黒皮を除去することが望ましいが、表
面状況が良好な際は、部分手入あるいは手入なし
でもよい。 In addition, in b, it is desirable to completely remove the black scale before loading the steel into the iron tube, but if the surface condition is good, partial or no treatment may be sufficient.
また、鉄筒の材質は、熱間変形抵抗及び熱膨脹
特性を一致させるため、ステンレス鋼を用いるの
もよいが、コスト面からは軟鋼が好ましく、鉄筒
の厚みは、分塊圧延あるいは鍛造終了まで残存す
る程度の厚みが必要で、好ましくは２mm〜10mm厚
みである。 In addition, stainless steel may be used as the material for the steel tube in order to match hot deformation resistance and thermal expansion characteristics, but mild steel is preferable from a cost perspective. The thickness is required to be enough to remain, preferably 2 mm to 10 mm.
なお、長手両端面について鉄筒と該素材とを分
塊圧延あるいは鍛造中の端面よりの剥離を防ぐた
めに溶接付けするのもよい。 In addition, it is also possible to weld the iron tube and the material to both longitudinal end surfaces in order to prevent separation from the end surfaces during blooming or forging.
この発明におけるｆの鋼条片は、炭素鋼あるい
は熱間変形抵抗及び熱膨脹特性を一致させるた
め、ステンレス鋼を用いてもよいが、コスト面か
らは軟鋼が好ましい。また、鋼条片幅は、
５mm〜50mmが好ましい。 For the steel strip f in this invention, carbon steel or stainless steel may be used in order to match hot deformation resistance and thermal expansion characteristics, but mild steel is preferable from a cost standpoint. Further, the width of the steel strip is preferably 5 mm to 50 mm.
また、鋼条片の厚み及び溶接部の肉盛厚みは、
フイツシユテールの発生を抑え、歩留を上げるた
め、熱間圧延前及び圧延時の鋼素材より厚いほう
が好ましく、該素材より１mmから10mm厚くするこ
とが好ましい。 In addition, the thickness of the steel strip and the overlay thickness of the welded part are
In order to suppress the occurrence of fish tails and increase the yield, it is preferable that the steel material be thicker than the steel material before hot rolling and during rolling, and preferably 1 mm to 10 mm thicker than the steel material.
この発明におけるｆの肉盛溶接鋼は、溶接時及
び加熱時の割れを防ぐため、Ｂ含有オーステナイ
トステンレス鋼の熱膨脹特性と一致させると共に
圧延時に割れを生じないため、Ｂ含有オーステナ
イトステンレス鋼と熱間変形抵抗の差が少ない、
オーステナイトステンレス鋼を用いる必要があ
る。 In order to prevent cracking during welding and heating, the overlay welded steel f in this invention matches the thermal expansion characteristics of B-containing austenitic stainless steel and does not crack during rolling. There is little difference in deformation resistance,
Austenitic stainless steel must be used.
また、ｆの肉盛溶接における開先角度は、鋼素
材と鋼条片が溶接できる範囲でよく、5゜〜60゜が
望ましく、所要角度に応じて、鋼素材および／ま
たは鋼条片の隅部の面取を行なえばよい。また、
鋼素材の四隅部は歩留を考慮して面取を施さなく
てもよい。 In addition, the groove angle in overlay welding f may be within a range that allows the steel material and the steel strip to be welded, preferably 5° to 60°, and depending on the required angle, the angle of the groove of the steel material and/or the steel strip All you have to do is chamfer the part. Also,
The four corners of the steel material do not need to be chamfered in consideration of yield.
作用効果
この発明の製造方法により、熱間加工性が大幅
に改善され、熱間加工時に加工材の長手方向縁部
に割れやひび疵のない品質良好な高Ｂ含有オース
テナイトステンレス鋼が得られるが、その理由は
以下のとおりである。Effects The production method of the present invention greatly improves hot workability, and produces high-quality, high-B content austenitic stainless steel with no cracks or cracks on the longitudinal edges of the workpiece during hot working. , the reason is as follows.
鋼素材を分塊圧延あるいは鍛造時に、鉄筒にて
４主面を密着包囲することにより、長手方向の縁
部に付加され易い加工時の引張力が、前記の鉄筒
により緩和されるとともに、外周面、特に冷却さ
れやすい長手方向縁部の温度低下を防止し、割れ
やひび疵を少なくする。 When the steel material is bloomed or forged, by closely surrounding the four main surfaces with an iron cylinder, the tensile force that is likely to be applied to the longitudinal edges during processing is alleviated by the iron cylinder, and Prevents temperature drop on the outer peripheral surface, especially the longitudinal edges that are easily cooled, and reduces cracks and cracks.
さらに、熱間加工時のロール接触あるいは冷却
水及び周囲温度の影響により、加工材の温度が低
下するとともに加工時に種々の引張力がかかり、
上述の所謂耳われ等を生じるが、この発明鋼は硼
化物とオーステナイト相との２相からなつてお
り、温度低下や引張力の負荷により、割れやひび
疵などが、一旦発生すると硼化物により次々と割
れやひび疵が伝播進行し、製品化できなくなるた
めに、特に初期の割れやひび疵を発生させないこ
とが重要であり、この発明方法では、表面の鉄層
を除去し、手入した鋼素材の長手両側面に、熱間
変形能の良好な鋼条片を肉盛溶接することによ
り、上記の温度低下が防止され、また、長手方向
の縁部に掛りやすい圧延時の引張力が、前記の鉄
筒、条片および肉盛溶接により緩和される。 Furthermore, due to roll contact during hot processing or the effects of cooling water and ambient temperature, the temperature of the workpiece decreases and various tensile forces are applied during processing.
The above-mentioned so-called ear cracking occurs, but the steel of this invention is composed of two phases: boride and austenite, and once cracks and cracks occur due to temperature drop and tensile force loading, boride causes cracks. Since cracks and cracks propagate one after another and make it impossible to produce a product, it is especially important to prevent initial cracks and cracks from occurring.In this invention method, the iron layer on the surface is removed and the By overlaying steel strips with good hot deformability on both longitudinal sides of the steel material, the above temperature drop is prevented, and the tensile force that tends to be applied to the longitudinal edges during rolling is reduced. , is relieved by the above-mentioned steel tube, strip and overlay welding.
また、この発明方法によつて、上述の如く圧延
素材への引張力が緩和できるとともに、ｆの鋼条
片及び溶接部の肉盛厚さを圧延素材厚さより１mm
〜10mm厚く調節することにより、熱間圧延による
フイツシユテールの発生量を少なくすることがで
き、歩留向上にすこぶる有効である。 In addition, by the method of this invention, the tensile force on the rolled material can be relaxed as described above, and the build-up thickness of the steel strip and welded part f can be reduced by 1 mm from the thickness of the rolled material.
By adjusting the thickness to ~10 mm, the amount of fish tails generated during hot rolling can be reduced, which is extremely effective in improving yield.
限定理由
この発明においてオーステナイトステンレス鋼
の成分限定理由は、以下のとおりである。Reason for limitation The reason for limiting the components of austenitic stainless steel in this invention is as follows.
Ｂは、中性子の吸収効果を有するために含有す
るが、0.5wt％未満では中性子吸収効果が少なく、
制御材、遮蔽板としての板厚が大きくなり、前述
の容器やラツクが大型化しコスト高となるため好
ましくなく、また、3.0wt％を超える含有では材
料の延び及び衝撃値が著しく劣化して構造材とし
て不適となるため、0.5wt％〜3.0wt％の範囲とす
る。 B is included to have a neutron absorption effect, but if it is less than 0.5 wt%, the neutron absorption effect is small;
This is undesirable because the thickness of the control material and shielding plate increases, which increases the size of the containers and racks mentioned above and increases costs.Additionally, if the content exceeds 3.0wt%, the elongation and impact value of the material will deteriorate significantly, resulting in poor structure. Since it is unsuitable as a material, it should be in the range of 0.5wt% to 3.0wt%.
Crは、本系においてNiと共に耐食性を得るた
めに含有するが、15wt％未満では、ステンレス
鋼として充分な耐食性が得られず、Crの含有量
の増加と共に耐食性は良好となるが、24wt％を
超える含有ではその効果が飽和し、コスト面で好
ましくないため、15wt％〜24wt％の範囲とする。 Cr is contained in this system along with Ni to obtain corrosion resistance, but if it is less than 15wt%, sufficient corrosion resistance cannot be obtained as a stainless steel.As the Cr content increases, corrosion resistance improves, but when 24wt% If the content exceeds the content, the effect will be saturated and it will be unfavorable in terms of cost, so the content should be in the range of 15 wt% to 24 wt%.
Niは、本系においてCrと共に耐食性を得るた
めに含有するが、6wt％未満では還元性雰囲気に
おける充分な耐食性が得られず、また、17wt％
を超える含有ではその効果が飽和し、コスト面で
好ましくないため、６〜17wt％の範囲とする。 Ni is included in this system together with Cr to obtain corrosion resistance, but if it is less than 6wt%, sufficient corrosion resistance cannot be obtained in a reducing atmosphere, and if it is less than 6wt%,
If the content exceeds the above, the effect will be saturated and it will be unfavorable in terms of cost, so the content should be in the range of 6 to 17 wt%.
この発明において、好ましいＢ含有オーステナ
イトステンレス鋼は、
B0.5wt％〜3.0wt％、
C0.15wt％以下、Si1.0wt％以下、
Mn2.5wt％以下、
P0.05wt％以下、S0.03wt％以下、
Cr15wt％〜24wt％、Ni6〜17wt％
残部実質的にFeからなるオーステナイトステ
ンレス鋼である。 In this invention, preferable B-containing austenitic stainless steels include B0.5wt% to 3.0wt%, C0.15wt% or less, Si1.0wt% or less, Mn2.5wt% or less, P0.05wt% or less, S0.03wt% or less. , Cr15wt%~24wt%, Ni6~17wt% The balance is an austenitic stainless steel consisting essentially of Fe.
Ｃは、0.15wt％を超えると粒界に炭化物を生成
し易くなり、粒界腐蝕を起し易くなり、耐食性が
劣化して好ましくないため、0.15wt％以下とす
る。 If C exceeds 0.15 wt%, carbides tend to form at grain boundaries, which tends to cause intergranular corrosion, resulting in deterioration of corrosion resistance, which is undesirable.
Siは、製鋼工程における精練に効果があるとと
もに、耐酸化性及び溶接性の改善に有効である
が、1.0wt％を超える含有はその効果が飽和して
コスト的に好ましくないため、1.0wt％以下とす
る。 Si is effective in refining in the steelmaking process and is effective in improving oxidation resistance and weldability, but if the content exceeds 1.0wt%, the effect will become saturated and it is unfavorable in terms of cost. The following shall apply.
Mnは、製鋼工程において、脱酸、脱硫効果が
あるとともに、オーステナイト組織を安定化さ
せ、また、高温での耐酸化性が得られるが、
2.5wt％を超えると反つて低下するため、2.5wt％
以下とする。 Mn has deoxidizing and desulfurizing effects in the steelmaking process, stabilizes the austenite structure, and provides oxidation resistance at high temperatures.
If it exceeds 2.5wt%, it will warp and decrease, so 2.5wt%
The following shall apply.
Ｐ、Ｓは、応力腐蝕割れを発生し易くなるた
め、P0.05wt％以下、S0.03wt％以下とする必要
がある。 Since P and S tend to cause stress corrosion cracking, P and S need to be kept at 0.05 wt% or less and S at 0.03 wt% or less.
本系ステンレス鋼において、残部は、Feと不
可避的不純物である。 In this stainless steel, the remainder is Fe and unavoidable impurities.
また、本系ステンレス鋼において、耐酸性向上
のため、Mo4wt％以下を含有してもよく、オー
ステナイト安定化、結晶粒子微細化及び靭性向上
のため、N20.30wt％以下を含有してもよい。 In addition, in this stainless steel, Mo4wt% or less may be contained to improve acid resistance, and N2 may be contained 0.30wt% or less to stabilize austenite, refine crystal grains, and improve toughness. .
また、この発明方法において、分塊圧延、鍛造
並びに熱間圧延の温度を950℃〜1250℃としたの
は、950℃未満では、鋼素材の変形抵抗が大きく、
変形能が低下し、われ疵などを発生するため好ま
しくなく、また、1250℃を超えると、結晶粒の粗
大化が起り、われ発生を惹起するためである。 In addition, in the method of this invention, the temperature of blooming, forging, and hot rolling is set to 950°C to 1250°C, because the deformation resistance of the steel material is large below 950°C.
This is undesirable because the deformability decreases and cracks occur, and if the temperature exceeds 1250°C, the crystal grains become coarser, causing cracks.
また、１パス当りの圧下率を10％〜70％とした
のは、10％未満では硼化物の充分な微細分散化を
計ることができず、また、70％を超えると加工度
が大きくなりすぎ、われまたはひび疵が発生し易
くなるためである。 In addition, the reduction rate per pass was set at 10% to 70% because if it is less than 10%, sufficient fine dispersion of the boride cannot be achieved, and if it exceeds 70%, the degree of processing becomes large. This is because scratches, cracks, and cracks are more likely to occur.
実施例
実施例 １
B1.96wt％、C0.55wt％、
Si0.39wt％、Mn1.54wt％、
Cr18.2wt％、Ni10.5wt％
P0.010wt％、S0.004wt％、
残部実質的にFeからなるオーステナイトステ
ンレス鋼を、上辺274mm×164mm、下辺269mm×119
mm高さ630mm寸法の190Kgの平板状鋼塊となし、手
入により鋳肌表面を除去して清浄化し、押湯部切
断後、長手方向の上下面と両側面の４主面に、厚
み４mmのC0.12％の鋼板の溶接組立体よりなる軟
鋼筒にて密着包囲したのち、これをプレス鍛造に
より、1200℃で、厚み50mm×幅268mm×長さ1870
mmに鍛造した。ExamplesExample 1 B1.96wt%, C0.55wt%, Si0.39wt%, Mn1.54wt%, Cr18.2wt%, Ni10.5wt% P0.010wt%, S0.004wt%, balance essentially made of Fe Made of austenitic stainless steel, top side 274mm x 164mm, bottom side 269mm x 119mm.
A flat steel ingot weighing 190 kg with a height of 630 mm was prepared, the cast surface was removed and cleaned, and after cutting the feeder part, the four main surfaces of the upper and lower surfaces and both sides in the longitudinal direction were made with a thickness of 4 mm. After tightly enclosing it in a mild steel tube made of a welded assembly of C0.12% steel plates, this was press-forged at 1200℃ into a 50mm thick x 268mm wide x 1870mm long tube.
Forged to mm.
その後、鋼素材表面の軟鉄層部分を切削除去
し、厚み46mm×幅260mm×長さ1870mm寸法の該素
材の両側面四隅を角度θ＝5゜、面取長さｌ＝22mm
の面取加工を行なつた。 After that, the soft iron layer part on the surface of the steel material is cut away, and the four corners of both sides of the material with dimensions of 46 mm thickness x 260 mm width x 1870 mm length are chamfered at an angle θ = 5° and a chamfer length l = 22 mm.
The chamfering process was carried out.
C0.12％、厚み50mm×幅20mm×長さ1900mm寸法
よりなる軟鋼鋼の条片に、一方側面の二隅を角度
θ′＝30゜、面取長さl′＝24mmの面取加工を行なつ
た。 A strip of mild steel with C0.12% and dimensions of 50 mm thick x 20 mm wide x 1900 mm long is chamfered at two corners of one side with an angle θ' = 30° and chamfer length l' = 24 mm. I did it.
ついで、鋼素材の両側面に、前記条片の面取加
工面を長手中央に突合せて密着させ、面取部で形
成される凹部に、Cr19.9wt％、Ni9.5wt％、残部
Feからなるオーステナイトステンレス鋼を、肉
盛溶接して、幅300mm×長さ1900mm、軟鋼条片及
び肉盛溶接部厚みは50mm、鋼素材厚みは46mmにし
た。 Next, the chamfered surfaces of the strips are brought into close contact with each other on both sides of the steel material, and the chamfered surfaces are brought into contact with each other in the longitudinal center, and 19.9wt% Cr, 9.5wt% Ni, and the remainder are placed in the recesses formed by the chamfers.
Austenitic stainless steel made of Fe was overlay welded to a width of 300 mm x length of 1900 mm, a mild steel strip and overlay welded part thickness of 50 mm, and a steel material thickness of 46 mm.
その後、1220℃に加熱し、１パス当りの圧下率
41％の熱間圧延を行ない、４パスで板厚６mm×幅
315mm×長さ13800mm寸法の板材となした。 After that, it is heated to 1220℃, and the rolling reduction rate per pass is
41% hot rolling, 6mm thickness x width in 4 passes
It was made into a board with dimensions of 315mm x length 13800mm.
熱間圧延後に、1050℃、0.5時間の熱処理を行
ない、水冷し、板材の外表面の軟鉄及びステンレ
ス鋼層部分を切削除去するとともに表面酸化層を
除去し、レベラーにより平坦度を矯正し、最終仕
上寸法として、板厚5.5mm×幅255mm×長さ13500
mm寸法の板材となした。 After hot rolling, heat treatment is carried out at 1050℃ for 0.5 hours, water cooling is performed, the soft iron and stainless steel layers on the outer surface of the plate are removed, the surface oxidation layer is removed, and the flatness is corrected using a leveler. Finished dimensions: plate thickness 5.5mm x width 255mm x length 13500
It was made into a plate material with mm dimensions.
また、比比較例として、上記組成のオーステナ
イトステンレス鋼の190Kg平板状鋼塊を軟鋼筒に
て密着包囲せず、プレス鍛造し、また軟鋼条片を
溶接せず、そのまま熱間圧延したが、得られた製
品の最終寸法は板厚5.5mm×幅255mm×長さ5800mm
であつた。 As a comparative example, a 190 kg flat steel ingot of austenitic stainless steel with the above composition was press-forged without being tightly enclosed in a mild steel tube, and the mild steel strip was hot-rolled as it was without welding. The final dimensions of the finished product are board thickness 5.5mm x width 255mm x length 5800mm.
It was hot.
得られた２種のオーステナイトステンレス熱間
圧延材の加工における各々の加熱回数と耳割れ状
況及び製品歩留（最終製品／鋼塊×100％）を調
べ、第１表にその結果を示す。 The number of heating times, edge cracking, and product yield (final product/steel ingot x 100%) during processing of the two types of hot-rolled austenitic stainless steel materials obtained were investigated, and the results are shown in Table 1.
■■■ 亀の甲 ［0019］ ■■■
実施例 ２
B2.2wt％、C0.02wt％、
Si0.41wt％、Mn1.55wt％、
Cr19.2wt％、Ni10.8wt％
P0.009wt％、S0.011wt％、
残部実質的にFeからなるオーステナイトステ
ンレス鋼の溶鋼を、上面φ270mm×底面φ200mm×
高さ620mm、鋳型厚み65mmの鋳型内に嵌入した内
径φ260mm×φ190mm×高さ620mm、板厚み５mm寸
法、C0.18％の軟鋼筒内に、鋳込みし、外周面に
厚み５mmの鉄皮を溶着した250Kgの鋼塊を造壊し
た。■■■ Turtle shell [0019] ■■■ Example 2 B2.2wt%, C0.02wt%, Si0.41wt%, Mn1.55wt%, Cr19.2wt%, Ni10.8wt% P0.009wt%, S0.011wt %, the remainder of the austenitic stainless steel molten steel consists essentially of Fe, and the top surface is φ270 mm x the bottom surface is φ200 mm.
Cast into a 0.18% C0.18% mild steel cylinder with an inner diameter of 260 mm x 190 mm in height and a plate thickness of 5 mm fitted in a mold with a height of 620 mm and a mold thickness of 65 mm, and a 5 mm thick iron skin is welded to the outer peripheral surface. A 250Kg steel ingot was demolished.
その後、1200℃に加熱し、１パス当りの圧下率
15〜70％のプレス鍛造を施し、押湯部を切断し厚
み60mm×幅240mm×長さ2395mmに鍛造した。 After that, it is heated to 1200℃ and the rolling reduction rate per pass is
After applying 15 to 70% press forging, the feeder section was cut and forged to a thickness of 60 mm, width of 240 mm, and length of 2395 mm.
その後、鋼素材表面の軟鉄層部分を切削除去し
て厚み54mm×幅230mmにし、長手方向に３分割後、
該素材の両側面四隅を角度θ＝20゜、面取長さｌ
＝24mmの面取加工を行なつた。 After that, the soft iron layer on the surface of the steel material was removed to make the material 54mm thick x 230mm wide, and divided into three parts in the longitudinal direction.
The four corners of both sides of the material are chamfered at an angle θ = 20° and a chamfer length l.
=24mm chamfering process was performed.
C0.17％、厚み55mm×幅25mm寸法よりなる軟鋼
の条片に、一方側面の二隅を角度θ′＝30゜、面取
長さl′＝24.55mmの面取加工を行なつた。 A strip of mild steel with C0.17% and dimensions of 55 mm in thickness and 25 mm in width was chamfered at two corners on one side at an angle θ' = 30° and a chamfer length l' = 24.55 mm.
ついで、鋼素材の両側面に、前記条片の面取加
工面を突合せて密着させ、面取部で形成される凹
部に、Cr18.4wt％、Ni9.7wt％、残部Feからなる
オーステナイトステンレス鋼を、肉盛溶接して、
幅280mm×長さ790mm、軟鋼条片及び肉盛溶接部厚
みは55mm、鋼素材厚みは54mmにした。 Next, the chamfered surfaces of the strips are brought into close contact with both sides of the steel material, and austenitic stainless steel consisting of 18.4wt% Cr, 9.7wt% Ni, and the balance Fe is placed in the recess formed by the chamfer. , overlay welding,
The width was 280mm x the length was 790mm, the thickness of the mild steel strip and overlay welding was 55mm, and the thickness of the steel material was 54mm.
その後、1200℃に加熱し、１パス当りの圧下率
41％の熱間圧延を行ない、５パスで板厚４mm×幅
305mm×長さ9800mm寸法となした。 After that, it is heated to 1200℃ and the rolling reduction rate per pass is
41% hot rolling, 4mm thickness x width in 5 passes
The dimensions were 305mm x length 9800mm.
熱間圧延後に長手方向に２分割し、1000℃、１
時間の熱処理を行ない、水冷後板材の外表面の軟
鉄及びステンレス鋼層部分を切削除去するととも
に表面酸化層を除去し、レベラーにより平坦度を
矯正し、最終仕上寸法として、板厚3.5mm×幅225
mm×長さ4850mm寸法の板材６枚となした。 After hot rolling, it was divided into two in the longitudinal direction and heated at 1000℃ for 1
After cooling with water, the soft iron and stainless steel layers on the outer surface of the plate are removed, the surface oxidation layer is removed, and the flatness is corrected using a leveler.The final dimensions are 3.5 mm thick x width. 225
It was made of 6 plates with dimensions of mm x length 4850 mm.
また、比較例として、上記組成のオーステナイ
トステンレス鋼をそのまま鍛造及び熱間圧延し、
同様の最終仕上寸法となした。得られた製品枚数
は２枚であつた。 In addition, as a comparative example, austenitic stainless steel with the above composition was forged and hot rolled as it was,
The final dimensions were the same. The number of products obtained was two.
得られた２種のオーステナイトステンレス熱間
圧延材の加工における各々の加熱回数と、耳割れ
状況及び製品歩留（最終製品／鋼塊×100％）を
調べ、第２表にその結果を示す。 The number of times of heating, edge cracking, and product yield (final product/steel ingot x 100%) during processing of the two types of hot-rolled austenitic stainless steel materials obtained were investigated, and the results are shown in Table 2.
■■■ 亀の甲 ［0020］ ■■■
発明の効果
第１表及び第２表の結果より明らかな如く、こ
の発明の製造方法によつて、難加工性である高Ｂ
含有オーステナイトステンレス鋼の熱間加工性が
大幅に改善され、製品歩留の著しい向上が認めら
れ、核燃料保管用ラツクや使用済み核燃料保管用
ラツク等の小形化と低コスト化に有利な薄肉化が
容易に得られることが分る。■■■ Tortoise shell [0020] ■■■ Effect of the invention As is clear from the results in Tables 1 and 2, the manufacturing method of the present invention produces high B, which is difficult to process.
The hot workability of austenite-containing stainless steel has been significantly improved, and the product yield has been significantly improved, and thinner walls are advantageous for downsizing and cost reduction of nuclear fuel storage racks and spent nuclear fuel storage racks. It turns out that it is easily obtained.
第１図はこの発明の製造方法を示す鋼素材と鋼
条片との縦断面説明図である。
１……鋼素材、２，４……面取、３……鋼条
片、５……肉盛。
FIG. 1 is an explanatory longitudinal cross-sectional view of a steel material and a steel strip showing the manufacturing method of the present invention. 1... Steel material, 2, 4... Chamfering, 3... Steel strip, 5... Overlay.
Claims (1)
％−Ni6wt％〜17wt％系オーステナイトステン
レス鋼素材の少なくとも４主面を鉄筒にて密着包
囲し、分塊圧延あるいは鍛造し、 該素材表面の鉄層を除去したのち、該素材の厚
み側両側面に、１側面を面取加工した厚みが該素
材厚みより１mm〜10mm厚い鋼条片を密着させ、 該素材と鋼条片との間に形成される凹部に、オ
ーステナイトステンレス鋼にて該素材より １mm〜10mm厚い肉盛溶接した後、 950℃〜1250℃に加熱し、１パス当りの圧下率10
％〜70％で、少なくとも１回の熱間圧延を行つた
後、外表面の鋼条片層及びオーステナイトステン
レス鋼層部分を除去することを特徴とするＢ含有
オーステナイトステンレス鋼の製造方法。[Claims] 1 Cr15wt% to 24wt containing B0.5wt% to 3.0wt%
At least four main surfaces of a %-Ni6wt%~17wt% austenitic stainless steel material are closely surrounded by iron cylinders, and the iron layer on the surface of the material is removed by blooming rolling or forging, and then both sides of the thickness side of the material are A steel strip with one side chamfered and having a thickness of 1 mm to 10 mm thicker than the material is closely attached to the surface, and the material is made of austenitic stainless steel into the recess formed between the material and the steel strip. After overlay welding 1mm to 10mm thicker, heat to 950℃ to 1250℃ and reduce the reduction rate to 10 per pass.
% to 70%, and then hot rolling is performed at least once, and then the steel strip layer and the austenitic stainless steel layer portion on the outer surface are removed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6584585A JPS61222612A (en) | 1985-03-28 | 1985-03-28 | Production of b-containing austenite stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6584585A JPS61222612A (en) | 1985-03-28 | 1985-03-28 | Production of b-containing austenite stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61222612A JPS61222612A (en) | 1986-10-03 |
| JPH0354007B2 true JPH0354007B2 (en) | 1991-08-16 |
Family
ID=13298751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6584585A Granted JPS61222612A (en) | 1985-03-28 | 1985-03-28 | Production of b-containing austenite stainless steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61222612A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6376703A (en) * | 1986-09-18 | 1988-04-07 | Nippon Steel Corp | Production of high-b stainless steel for shielding thermal neutron |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5534636A (en) * | 1978-08-30 | 1980-03-11 | Hitachi Metals Ltd | Boron-containing austenitic stainless steel with superior hot workability for nuclear reactor |
| JPS5791804A (en) * | 1980-11-29 | 1982-06-08 | Daido Steel Co Ltd | Rolling method for sendust alloy |
| JPS58187212A (en) * | 1982-04-26 | 1983-11-01 | Furukawa Electric Co Ltd:The | Hot working method of metallic material of hard workability |
| JPS59150603A (en) * | 1983-02-18 | 1984-08-28 | Nippon Steel Corp | Manufacture of brittle steel sheet |
| JPS59212103A (en) * | 1983-05-18 | 1984-12-01 | Mitsubishi Electric Corp | Manufacture of rolled shape-sheet |
-
1985
- 1985-03-28 JP JP6584585A patent/JPS61222612A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5534636A (en) * | 1978-08-30 | 1980-03-11 | Hitachi Metals Ltd | Boron-containing austenitic stainless steel with superior hot workability for nuclear reactor |
| JPS5791804A (en) * | 1980-11-29 | 1982-06-08 | Daido Steel Co Ltd | Rolling method for sendust alloy |
| JPS58187212A (en) * | 1982-04-26 | 1983-11-01 | Furukawa Electric Co Ltd:The | Hot working method of metallic material of hard workability |
| JPS59150603A (en) * | 1983-02-18 | 1984-08-28 | Nippon Steel Corp | Manufacture of brittle steel sheet |
| JPS59212103A (en) * | 1983-05-18 | 1984-12-01 | Mitsubishi Electric Corp | Manufacture of rolled shape-sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61222612A (en) | 1986-10-03 |
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