JPH0215117A - Production of prehardened die steel for forming plastic - Google Patents
Production of prehardened die steel for forming plasticInfo
- Publication number
- JPH0215117A JPH0215117A JP16549488A JP16549488A JPH0215117A JP H0215117 A JPH0215117 A JP H0215117A JP 16549488 A JP16549488 A JP 16549488A JP 16549488 A JP16549488 A JP 16549488A JP H0215117 A JPH0215117 A JP H0215117A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- toughness
- machinability
- ferrite
- austenite
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 64
- 239000010959 steel Substances 0.000 title claims abstract description 63
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 239000004033 plastic Substances 0.000 title abstract description 5
- 229920003023 plastic Polymers 0.000 title abstract description 5
- 238000011282 treatment Methods 0.000 claims abstract description 27
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 17
- 230000032683 aging Effects 0.000 claims abstract description 16
- 238000010137 moulding (plastic) Methods 0.000 claims abstract description 15
- 229910001566 austenite Inorganic materials 0.000 claims abstract description 10
- 229910000734 martensite Inorganic materials 0.000 claims abstract description 10
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 8
- 229910001563 bainite Inorganic materials 0.000 claims abstract description 7
- 239000012535 impurity Substances 0.000 claims abstract description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 10
- 229910052742 iron Inorganic materials 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- 239000000203 mixture Substances 0.000 abstract description 4
- 229910052804 chromium Inorganic materials 0.000 abstract description 3
- 229910052802 copper Inorganic materials 0.000 abstract description 2
- 229910052748 manganese Inorganic materials 0.000 abstract description 2
- 229910000851 Alloy steel Inorganic materials 0.000 abstract 1
- 229910052750 molybdenum Inorganic materials 0.000 abstract 1
- 229910052759 nickel Inorganic materials 0.000 abstract 1
- 229910052720 vanadium Inorganic materials 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- 150000001247 metal acetylides Chemical class 0.000 description 4
- 229910000765 intermetallic Inorganic materials 0.000 description 3
- 238000005275 alloying Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000005242 forging Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 238000004881 precipitation hardening Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000006104 solid solution Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000003483 aging Methods 0.000 description 1
- 229910001567 cementite Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- KSOKAHYVTMZFBJ-UHFFFAOYSA-N iron;methane Chemical compound C.[Fe].[Fe].[Fe] KSOKAHYVTMZFBJ-UHFFFAOYSA-N 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/001—Heat treatment of ferrous alloys containing Ni
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Forging (AREA)
Abstract
Description
【発明の詳細な説明】
産栗上■赳貝分団
本発明は、プラスチック成形用プレハードン金型鋼の製
造方法に関し、詳しくば、ＨＲＣ３５〜４５としてなる
被削性、靭性及び鏡面性にすぐれるプラスチック成形用
プレハードン金型鋼の製造方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing pre-hardened mold steel for plastic molding, and more specifically, to a method for manufacturing pre-hardened mold steel for plastic molding, specifically for molding plastics having excellent machinability, toughness and specularity with a HRC of 35 to 45. The present invention relates to a method for producing pre-hardened mold steel for use in industrial applications.
ｌ米少狡査
プラスチック成形用プレハードン金型鋼には、成形対象
である樹脂、成形品の用途等に応じて、硬さ、鏡面性、
耐食性等が要求されるのみならず、金型加工の点から被
削性が要求される。特に、ＨＲＣ３５以上の高硬度金型
は加工が困難であるので、被削性の改善が強く要望され
ている。Pre-hardened mold steel for plastic molding has hardness, specularity, and
Not only is corrosion resistance required, but machinability is also required from the viewpoint of mold processing. In particular, since it is difficult to process molds with high hardness of HRC 35 or higher, there is a strong demand for improvement in machinability.
ＨＲＣ３５〜４５の析出硬化型金型鋼としては、既に、
特開昭５２−６５５５７号公報、特開昭５５−２８３８
４号公報、特開昭６１−１１７２５６号公報等に記載さ
れているように、鋼の被削性を改善するための合金元素
としてＣｕを用いており、更に、硬さを確保するために
、Ｃｕに加えて、ＭＯｌＣｒ、Ｍｎ等の析出硬化や焼入
れ性を向上させる元素を相当量加えており、その結果と
して、靭性の低下を避けることができない。As precipitation hardening mold steel with HRC35-45,
JP-A-52-65557, JP-A-55-2838
As described in Publication No. 4, Japanese Patent Application Laid-Open No. 61-117256, etc., Cu is used as an alloying element to improve the machinability of steel, and furthermore, in order to ensure hardness, In addition to Cu, a considerable amount of elements that improve precipitation hardening and hardenability, such as MOlCr and Mn, are added, and as a result, a decrease in toughness cannot be avoided.
また、従来、プラスチック成形用プレハードン金型鋼の
製造においては、被削性を付与するために、通常、Ｓが
増量されている。しかし、Ｓの増量は、金型鋼の靭性を
低下させると共に、鏡面性をも劣化させるので、その添
加量には自ずから限度がある。更に、上記した従来の金
型鋼は、いずれも、所要の硬さを確保するために、オー
ステナイト域から冷却して、その金属組織をマルテンサ
イト又はベイナイトとしている。Furthermore, in the conventional production of pre-hardened mold steel for plastic molding, the amount of S is usually increased in order to impart machinability. However, since increasing the amount of S reduces the toughness of the mold steel and also deteriorates the specularity, there is naturally a limit to the amount of S added. Furthermore, in order to ensure the required hardness, all of the above-mentioned conventional mold steels are cooled from the austenite region to change the metal structure to martensite or bainite.
しかしながら、近年においては、プラスチック成形品の
種類や用途も多様化し、複雑な形状の成形品が増加して
おり、他方、成形圧の上昇もあって、靭性の低い前記し
た従来のプレハードン金型鋼は、欠は等を生じて、十分
な寿命をもたない。However, in recent years, the types and uses of plastic molded products have diversified, and the number of molded products with complex shapes has increased.On the other hand, due to the increase in molding pressure, the conventional pre-hardened mold steel with low toughness has become less tough. , defects, etc. occur, and it does not have a sufficient lifespan.
が ゛ しようとする
本発明者らは、上記した問題を解決するために鋭意研究
した結果、プラスチック金型用プレバトン鋼の製造にお
いて、合金元素の選択及び添加量を最適に選択制御する
と共に、金型組織をフェライト及びマルテンサイト（又
はヘイナイ１〜）の相組織とし、又は、鋼中のＭｎＳの
アスペクト比を制御することによって、ＨＰＯ３５〜４
５であって、しかも、靭性、被削性及び鏡面性のすべて
を備えたプラスチック成形用プレハードン鋼金型鋼を得
ることができることを見出して、本発明に至ったもので
ある。As a result of intensive research to solve the above-mentioned problems, the inventors of the present invention have optimally controlled the selection and addition amount of alloying elements in the production of prebaton steel for plastic molds. By making the mold structure a ferrite and martensite (or Heinai 1~) phase structure, or by controlling the aspect ratio of MnS in the steel, HPO35~4
The present invention has been achieved based on the discovery that it is possible to obtain a pre-hardened mold steel for plastic molding which has all of the following properties: 5, toughness, machinability, and specularity.
従って、本発明は、）（ＲＣ３５〜４５であって、しか
も、靭性、被削性及び鏡面性のすべてを備えたプラスチ
ック成形用プレハ−ドン金型鋼を提供することを目的と
する。Therefore, an object of the present invention is to provide a pre-hardened mold steel for plastic molding, which has an RC of 35 to 45 and has all of toughness, machinability and specularity.
課題を解決するだめの手段
本発明によるプラスチック成形用プレハ−ドン金型鋼の
製造方法は、重量％で
（ａ＋ Ｇ ０．０５〜０．２０％、Ｓｉ０．１０
〜１．０％、
Ｍｎ １．０〜２．０％、
Ｓ ０．０３〜０．３０％、
Ｎｉ３．５〜５．０％、
Ｃｒ ０．２０〜１．００％、
Ｍｏ０．３０％、
７Ｂｏ、７ｏ〜１．５０％、及び
Ｃｕ０．３０％以下を含有し、更に、
（ｂ）Ｖ ０．０５〜０．３０％、及びＮｂ０．０
５〜０．１５％
よりなる群から選ばれる少なくとも１種の元素を含有し
、
残部鉄及び不可避的不純物よりなる鋼を溶体化処理及び
時効処理を施して、ＨＲＣ３５〜４５としてなる被削性
、靭性及び鏡面性にすぐれるプラスチック成形用プレハ
ードン金型鋼を得るものである。Means for Solving the Problems The method of manufacturing a pre-hardened mold steel for plastic molding according to the present invention is based on a method for producing a pre-hardened mold steel for plastic molding, in which (a + G 0.05-0.20%, Si 0.10
~1.0%, Mn 1.0~2.0%, S 0.03~0.30%, Ni3.5~5.0%, Cr 0.20~1.00%, Mo0.30%, Contains 7Bo, 7o ~ 1.50%, and Cu 0.30% or less, and furthermore, (b) V 0.05 ~ 0.30%, and Nb 0.0
A steel containing at least one element selected from the group consisting of 5 to 0.15%, with the balance consisting of iron and unavoidable impurities, is subjected to solution treatment and aging treatment to obtain a HRC of 35 to 45. A pre-hardened mold steel for plastic molding having excellent toughness and specularity is obtained.
先ず、本発明鋼における化学成分の限定理由を説明する
。First, the reason for limiting the chemical components in the steel of the present invention will be explained.
本発明においては、溶体化温度又は二相域温度から空冷
して、マルテンサイト （又はへイナイ日に基づく硬さ
を確保するために、Ｃは、０．０５％以上を添加するこ
とか必要である。しかし、過多に添加するときは、Ｃｒ
、Ｍｏ、ＶＸＮｂ等の炭化物を過剰に形成して、靭性と
被削性を概するので、添加量は０．２０％以下とする。In the present invention, C must be added in an amount of 0.05% or more to ensure hardness based on martensite (or hardness) by air cooling from solution temperature or two-phase temperature. However, when adding too much Cr
, Mo, VXNb, etc. are formed in excess to improve toughness and machinability, so the amount added is set to 0.20% or less.
Ｓｉは、焼入れ性を高めて、硬さを高くすると同時に、
熔解時の脱酸剤としても不可欠であって、かかる観点か
ら、少なくとも０．１０％の添加を必要とする。しかし
、過多に添加するときは、硬質の酸化物５ｉ０２を生成
して、被削性を阻害するので、添加量の上限を１．０％
とする。Si improves hardenability and hardness, and at the same time,
It is also essential as a deoxidizing agent during melting, and from this point of view, it is necessary to add at least 0.10%. However, when adding too much, hard oxide 5i02 is generated and machinability is impaired, so the upper limit of the amount added is 1.0%.
shall be.
Ｍｎは、焼入れ性を高めて硬さを大きくすると同時に、
鋼に被削性を付与する介在物ＭｎＳを形成させるために
、１．０％以上の添加を必要とする。Mn improves hardenability and increases hardness, and at the same time,
In order to form MnS inclusions that impart machinability to steel, it is necessary to add 1.0% or more of MnS.
しかし、２．０％を越えて過多に添加するときは、焼入
れ硬さが高ずぎて、被削性と靭性を劣化させる。However, when added in excess of 2.0%, the quenching hardness becomes too high and machinability and toughness deteriorate.
本発明において、Ｓば、前述したように、Ｍｎと結合し
てＭｎＳを生成し、鋼にずくれた被削性を付与する重要
な元素の一つであって、かかる効果を有効に得るために
、少なくとも０．０３０％を添加する。しかし、過多に
添加するときば、靭性と鏡面性とを劣化させるので、添
加量は０．３０％以下とする。In the present invention, as mentioned above, S is one of the important elements that combines with Mn to form MnS and imparts superior machinability to steel, and in order to effectively obtain this effect, Add at least 0.030% to. However, if added in excess, the toughness and specularity will deteriorate, so the amount added should be 0.30% or less.
Ｎｉも、本発明において、硬化析出と強靭化の二２の目
的を達成するために、重要な元素である。Ni is also an important element in the present invention in order to achieve the 22 objectives of hardening precipitation and toughening.
即ち、Ｎｉば、時効中にＡｌと結合し、微細な金属間化
合物を形成して、強度を確保するために、少なくとも２
．５％の添加を必要とする。更に、鋼中に固溶させて、
強靭性を高めるためには、１．０％以上を添加すること
が必要である。しかし、５゜０％を越える過多量の添加
は、残留オーステナイト量の増加によって、有効な強度
上昇を達成し得ないうえに、被削性を害し、更に、鋼の
製造費用をも高める。That is, Ni combines with Al during aging to form a fine intermetallic compound and to ensure strength, at least 2
．． Requires addition of 5%. Furthermore, by solid solution in steel,
In order to improve toughness, it is necessary to add 1.0% or more. However, addition of an excessive amount exceeding 5.0% increases the amount of retained austenite, making it impossible to achieve an effective increase in strength, impairing machinability, and further increasing the manufacturing cost of the steel.
Ｃｒは、焼入れ性を確保するために、０．２％以上添加
する必要がある。しかし、１．００％を越える過多量の
添加は、セメンタイト中へのＣｒの固溶や、Ｃｒ炭化物
の形成が顕著となって、被削性を著しく阻害する。Cr needs to be added in an amount of 0.2% or more to ensure hardenability. However, if the addition amount exceeds 1.00%, the solid solution of Cr in cementite and the formation of Cr carbides become significant, which significantly impedes machinability.
Ｍｏは、時効処理によって、微細な炭化物を形成し、Ｎ
１−Ａｆ金属間化合物と共に、強度を確保するために、
０．１０％以上を添加することが必要である。しかし、
添加量が０．３％を越えるときは、炭化物の生成が増大
し、被削性を低下させる。Mo forms fine carbides through aging treatment, and N
1-Af Together with the intermetallic compound, to ensure strength,
It is necessary to add 0.10% or more. but,
When the amount added exceeds 0.3%, carbide formation increases and machinability decreases.
Ａｌｌは、前述したように、Ｎｉとの間に微細な金属間
化合物を形成し、本発明において、時効硬化に必須の元
素であって、Ｎｉ量との関係がら、０．７％以上を添加
することが必要である。しかし、１．５％を越えて過多
に添加するときは、硬質の酸化物ＡＩ。０３を生成して
、被削性を害する。As mentioned above, All forms a fine intermetallic compound with Ni and is an essential element for age hardening in the present invention, and in relation to the amount of Ni, 0.7% or more of All is added. It is necessary to. However, when it is added in excess of 1.5%, it becomes a hard oxide AI. 03 and impairs machinability.
Ｃｕは、靭性を阻害する要因となると共に、熱間加工性
を阻害するので、可能な限りに少ないのがよいが、製鋼
上、ある程度、Ｃｕを含有することは避けられない。本
発明においては、含有量は、０．３０％以下は許容され
る。Cu is a factor that inhibits toughness and also inhibits hot workability, so it is best to minimize the amount of Cu, but it is unavoidable to contain Cu to some extent in terms of steel manufacturing. In the present invention, the content is allowed to be 0.30% or less.
■及びＮｂは、本発明においては、鋼に硬さと靭性とを
付与するために添加される重要な元素である。これらの
元素は、ＭＯと同様に、時効処理によって微細な炭化物
を生成して、硬さを向上させる効果を有するが、Ｍｏと
異なって、同時に結晶粒を微細化して、靭性を高めると
共に、鏡面性をも向上させる効果を有する。本発明にお
いては、かかる効果を有効に得るために、■を０．０５
％以上又はＮｂを０．０５％以上添加することが必要で
ある。しかし、これらの元素のいずれについても、過多
量の添加は、炭化物量の増大のために、結晶粒の微細化
による靭性の向上効果を相殺するので、添加量の上限は
、■については０．３％、Ｎｂについては０．１５％と
する。尚、■及びＮｂは、上記範囲内において、複合添
加してもよい。(2) and Nb are important elements added in the present invention to impart hardness and toughness to the steel. Similar to MO, these elements produce fine carbides through aging treatment and have the effect of improving hardness, but unlike Mo, they simultaneously refine crystal grains to improve toughness and create mirror-like surfaces. It also has the effect of improving sex. In the present invention, in order to effectively obtain such effects, ■ is set to 0.05.
% or more or 0.05% or more of Nb is required. However, for any of these elements, if too large a quantity is added, the increase in the amount of carbides cancels out the effect of improving toughness due to grain refinement, so the upper limit of the additive quantity is 0. 3%, and 0.15% for Nb. Note that ■ and Nb may be added in combination within the above range.
本発明によるプレハードン金型鋼は、上述した化学成分
を有する鋼に従来の通常の８５’Ｏ〜９゜０℃での溶体
化処理及び５００〜６００℃での時効処理を施すことに
よって、ＨＲＣ３’５〜４５を有すると共に、被削性、
靭性及び鏡面性にすぐれる。The pre-hardened mold steel according to the present invention is produced by subjecting steel having the above-mentioned chemical composition to conventional solution treatment at 85'O to 9.0°C and aging treatment at 500 to 600°C. ~45 and machinability,
Excellent toughness and specularity.
しかしながら、本発明によれば、上述した化学成分を有
する鋼をおよそ７００〜８００℃のオーステナイト・フ
エライトニ相域温度にて加熱処理することによって、フ
ェライト面積分率を２５〜７５％、残部をマルテンサイ
ト又はベイナイトの二相とし、その後、５００〜６００
’Ｃで時効処理を施すことによって、又はオーステナ
イト域における熱間加工に際して、鍛造加熱温度を１１
４０〜１２００℃にすること、及び据込鍛造を併用する
ことによって、鋼中のＭｎＳのアスペクト比（短軸長を
ａ、長軸長をｂとするとき、ｂ ／ ａ ）を２．５〜
１０の範囲内とし、その後、溶体化処理及び時効処理を
施すことによって、靭性及び鏡面性を阻害することなく
、被削性を一層顕著に改善することができる。However, according to the present invention, by heat-treating steel having the above-mentioned chemical composition at a temperature in the austenite-ferrite dual phase region of approximately 700 to 800°C, the area fraction of ferrite is reduced to 25 to 75%, and the remainder is martensite. Or two phases of bainite, then 500 to 600
By performing aging treatment at 'C or during hot working in the austenite region, the forging heating temperature is increased to 11
By heating the steel to 40 to 1200°C and using upsetting forging, the aspect ratio of MnS in the steel (b/a, where the short axis length is a and the long axis length is b) is 2.5 to 2.5.
10 and then subjected to solution treatment and aging treatment, machinability can be further significantly improved without impairing toughness and specularity.
プレハードン金型鋼の金属組織において、およそ８００
℃以下で加熱処理を行ない、フェライト面積分率を２５
％以上、残部をマルテンサイト又はベイナイトの二相と
するごとによって、通常熱処理鋼と同等の硬さを有しな
がら、被削性を向上させることができる。しかし、およ
そ７００°Ｃ以下で加熱処理を行った場合には、フェラ
イト面積分率が７５％を越え、ＨＲＣ３５以上の硬さを
得ることができない。In the metallographic structure of pre-hardened mold steel, approximately 800
Heat treatment is performed below ℃ to reduce the ferrite area fraction to 25
By making the remainder two-phase martensite or bainite, it is possible to improve machinability while maintaining hardness equivalent to that of ordinary heat-treated steel. However, when the heat treatment is performed at a temperature below about 700°C, the ferrite area fraction exceeds 75%, making it impossible to obtain a hardness of HRC 35 or higher.
また、鋼中のＭｎＳのアスペクト比が２．５よりも小さ
いときは、靭性が低く、他方、１０を越えても、被削性
の改善の効果が飽和する。しかし、上記のように、２．
５〜１０の範囲とすることによって、靭性及び鏡面性を
阻害することなく、被削性を一層顕著に改善することが
できる。Moreover, when the aspect ratio of MnS in steel is smaller than 2.5, the toughness is low, and on the other hand, even when it exceeds 10, the effect of improving machinability is saturated. However, as mentioned above, 2.
By setting it in the range of 5 to 10, machinability can be further significantly improved without impairing toughness and specularity.
特に、本発明によれば、上記の二つの処理による被削性
の向上効果は、それぞれ全く独立した機構によるもので
あるから、これらを組み合わせて、鋼中のＭｎＳのアス
ペクト比をオーステナイト域における熱間加工過程にて
２，５〜１０の範囲内とし、その後、オーステナイト・
フエライト二相域温度にて加熱処理して、フェライト面
積分率を２５〜７５％、残部をマルテンサイト又はヘイ
ナイ１〜〇二相に制御し、更にその後に、時効処理を施
すことによって、靭性及び鏡面性を損なうことなく、被
削性を一層向上させることができる。In particular, according to the present invention, the machinability improvement effect of the above two treatments is due to completely independent mechanisms, so by combining them, the aspect ratio of MnS in the steel can be adjusted by the heat in the austenite region. During the machining process, it is within the range of 2.5 to 10, and then austenite
Heat treatment is performed at a temperature in the ferrite two-phase region to control the ferrite area fraction to 25 to 75% and the remainder to martensite or Heinai 1 to 〇 two phases, followed by aging treatment to improve toughness and Machinability can be further improved without impairing specularity.
見所ｐ四果
以上のように、本発明によれば、従来の通常の溶体化処
理及び時効処理によって、靭性、被削性及び鏡面性にす
ぐれるプラスチック成形用プレハードン金型鋼を得るこ
とができる。しかし、本発明に従って、所定の化学成分
を有する鋼を二相域別熱によって所定のフェライト・マ
ルテンサイト（又はベイナイト）組織とすることによっ
て、又は熱間加工時にＭｎＳのアスペクＩ・比を所定の
範囲内とすることによって、その被削性を一層向上させ
ることができる。これら二相域別熱とＭｎＳのアスペク
ト比制御とを組み合わせれば、更に、被削性を向上させ
ることができる。Highlights As described above, according to the present invention, a pre-hardened mold steel for plastic molding having excellent toughness, machinability and specularity can be obtained by conventional ordinary solution treatment and aging treatment. However, according to the present invention, steel having a predetermined chemical composition is heated to a predetermined ferrite-martensite (or bainite) structure by heating in two-phase regions, or the aspect I ratio of MnS is changed to a predetermined value during hot working. By setting it within this range, the machinability can be further improved. If these two-phase region-specific heat and MnS aspect ratio control are combined, machinability can be further improved.
３３１ご（（リ−
以下に実施例を挙げて本発明を説明するが、本発明はこ
れら実施例により何ら限定されるものではない。331 ((Lee) The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples in any way.
実施例１及び２
第１表に示す化学成分を有する鋼のそれぞれについて、
通常のオーステナイト域溶体化及び時効処理を施して、
プレハードン金型鋼を得た。これらについて、金属組織
、２１Ｕノツチシヤルピー衝撃値（室温）及び工具寿命
を第２表に示す。ここに、工具寿命は、直径ＩＱｍｍの
エンドミル切削における逃げ面摩耗幅が０．２１１とな
る切削長さで評価し、本発明鋼１の工具寿命を１とする
相対寿命にて示す（以下、同じ）。Examples 1 and 2 For each of the steels having the chemical components shown in Table 1,
After normal austenite region solution treatment and aging treatment,
A pre-hardened mold steel was obtained. Table 2 shows the metallographic structure, 21U notch mechanical strength impact value (room temperature), and tool life of these. Here, the tool life is evaluated by the cutting length at which the flank wear width is 0.211 in end mill cutting with a diameter of IQ mm, and is expressed as a relative life with the tool life of the invention steel 1 as 1 (hereinafter, the same ).
本発明鋼は、通常の熱処理によって、所要の硬さを確保
しつつ、極めてずくれた靭性を有しており、工具寿命に
ついても、比較鋼と同等又はそれ以上である。The steel of the present invention secures the required hardness through ordinary heat treatment, has extremely poor toughness, and has a tool life that is equal to or longer than that of the comparative steel.
実施例３及び４
第１表における鋼１の溶体化処理を二相域で行なってプ
レハードン金型鋼を得た。金属組織、フェライト面積分
率、２ ｔｍ Ｕノツチシャルピー衝撃値（室温）及び
工具寿命を第３表に示す。フェライト面積分率が２５％
よりも少ないときは、工具寿命は、通常の溶体化処理の
場合と殆ど変わらず、他方、７５％を越えるときは、所
要硬さを得ることができない。これに対して、本発明に
従って、フェライト面積分率を２５〜７５％の範囲内と
することによって、所要硬さと良好な靭性を備えるのみ
ならず、工具寿命が更に向」ニしている。Examples 3 and 4 Pre-hardened mold steel was obtained by subjecting Steel 1 in Table 1 to solution treatment in a two-phase region. The metal structure, ferrite area fraction, 2 tm U notch Charpy impact value (room temperature) and tool life are shown in Table 3. Ferrite area fraction is 25%
When it is less than 75%, the tool life is almost the same as in the case of normal solution treatment, while on the other hand, when it is more than 75%, the required hardness cannot be obtained. On the other hand, according to the present invention, by setting the ferrite area fraction within the range of 25 to 75%, not only the required hardness and good toughness are provided, but also the tool life is further improved.
実施例５及び６
第１表における鋼１に通常の溶体化処理を施して、Ｍｎ
Ｓのアスペクト比の種々異なるプレバトン金型鋼を得た
。金属組織、フェライト面積分率、２龍Ｕノツチシヤル
ピー衝撃値（室温〉及び工具寿命を第４表に示す。Examples 5 and 6 Steel 1 in Table 1 was subjected to ordinary solution treatment to reduce Mn.
Prebaton mold steels having various S aspect ratios were obtained. Table 4 shows the metallographic structure, ferrite area fraction, 2-Dragon U-notch mechanical strength impact value (room temperature), and tool life.
比較例７によるアスペクト比２．１の鋼は、工具寿命に
はすぐれるものの、衝撃値が第２表比較例１〜３に示す
従来鋼よりも小さい。他方、比較例８によるアスペクト
比１３．９の鋼においては、靭性の向上がほぼ飽和して
おり、特に、このように、アスペクト比を大きくする必
要がないことを示す。Although the steel with an aspect ratio of 2.1 according to Comparative Example 7 has an excellent tool life, its impact value is smaller than the conventional steel shown in Comparative Examples 1 to 3 in Table 2. On the other hand, in the steel with an aspect ratio of 13.9 according to Comparative Example 8, the improvement in toughness is almost saturated, indicating that there is no need to increase the aspect ratio.
しかし、本発明に従って、アスペクト比を２．５〜１０
の範囲とすることによって、実施例５及び６にのられる
ように、衝撃値及び工具寿命のいずれにおいでも、従来
鋼である比較鋼１〜３と同等又はそれ以上である。However, according to the present invention, the aspect ratio can be changed from 2.5 to 10.
As shown in Examples 5 and 6, the impact value and tool life are equal to or greater than Comparative Steels 1 to 3, which are conventional steels.
特許出願人 株式会社神戸製鋼所 同 日本高周波鋼業株式会社 代理人 弁理士 牧 野 逸 部Patent applicant: Kobe Steel, Ltd. Japan Koshuha Steel Co., Ltd. Agent Patent Attorney Itsu Makino
Claims (4)
、 残部鉄及び不可避的不純物よりなる鋼を溶体化処理及び
時効処理を施して、ＨＲＣ３５〜４５としてなる被削性
、靭性及び鏡面性にすぐれるプラスチック成形用プレハ
ードン金型鋼の製造方法。(1) In weight% (a) C0.05-0.20%, Si0.10-1.0%, Mn1.0-2.0%, S0.03-0.30%, Ni3.5-5 .0%, Cr0.20~1.00%, Mo0.10~0.30%, Al0.70~1.50%, and Cu0.30% or less, and further, (b) V0.05~ A steel containing at least one element selected from the group consisting of 0.30% and 0.05 to 0.15% Nb, with the balance consisting of iron and unavoidable impurities is subjected to solution treatment and aging treatment to achieve HRC35. A method for producing a pre-hardened mold steel for plastic molding which has excellent machinability, toughness and specularity.
、 残部鉄及び不可避的不純物よりなる鋼をオーステナイト
・フエライト二相域温度にて加熱処理することによつて
、フェライト面積分率を２５〜７５％、残部をマルテン
サイト又はベイナイトの二相とし、その後、時効処理を
施して、ＨＲＣ３５〜４５としてなる被削性、靭性及び
鏡面性にすぐれるプラスチック成形用プレハードン金型
鋼の製造方法。(2) In weight% (a) C0.05-0.20%, Si0.10-1.0%, Mn1.0-2.0%, S0.03-0.30%, Ni3.5-5 .0%, Cr0.20~1.00%, Mo0.10~0.30%, Al0.70~1.50%, and Cu0.30% or less, and further, (b) V0.05~ A steel containing at least one element selected from the group consisting of 0.30% and 0.05 to 0.15% Nb, with the balance consisting of iron and unavoidable impurities is heat-treated at a temperature in the austenite-ferrite two-phase region. By doing so, the area fraction of ferrite becomes 25 to 75%, and the remainder is made into two phases of martensite or bainite. After that, aging treatment is performed to immediately improve machinability, toughness, and specularity as HRC35 to 45. A method for manufacturing pre-hardened mold steel for plastic molding.
、 残部鉄及び不可避的不純物よりなる鋼をオーステナイト
域において熱間加工するに際して、ＭｎＳのアスペクト
比を２．５〜１０の範囲内とし、その後、溶体化処理及
び時効処理を施して、ＨＲＣ３５〜４５としてなる被削
性、靭性及び鏡面性にすぐれるプラスチック成形用プレ
ハードン金型鋼の製造方法。(3) In weight% (a) C0.05-0.20%, Si0.10-1.0%, Mn1.0-2.0%, S0.03-0.30%, Ni3.5-5 .0%, Cr0.20~1.00%, Mo0.10~0.30%, Al0.70~1.50%, and Cu0.30% or less, and further, (b) V0.05~ When hot working steel containing at least one element selected from the group consisting of Nb 0.30% and Nb 0.05 to 0.15%, with the balance consisting of iron and unavoidable impurities in the austenite region, MnS A method for manufacturing pre-hardened mold steel for plastic molding with excellent machinability, toughness and specularity by setting the aspect ratio within the range of 2.5 to 10 and then subjecting it to solution treatment and aging treatment to obtain a HRC of 35 to 45. .
、 残部鉄及び不可避的不純物よりなる鋼をオーステナイト
域において熱間加工するに際して、ＭｎＳのアスペクト
比を２．５〜１０の範囲内とし、その後、オーステナイ
ト・フエライト二相域温度にて加熱処理することによつ
て、フェライト面積分率を２５〜７５％、残部をマルテ
ンサイト又はベイナイトの二相とし、更に、その後、時
効処理を施して、ＨＲＣ３５〜４５としてなる被削性、
靭性及び鏡面性にすぐれるプラスチック成形用プレハー
ドン金型鋼の製造方法。(4) In weight% (a) C0.05-0.20%, Si0.10-1.0%, Mn1.0-2.0%, S0.03-0.30%, Ni3.5-5 .0%, Cr0.20~1.00%, Mo0.10~0.30%, Al0.70~1.50%, and Cu0.30% or less, and further, (b) V0.05~ When hot working steel containing at least one element selected from the group consisting of Nb 0.30% and Nb 0.05 to 0.15%, with the balance consisting of iron and unavoidable impurities in the austenite region, MnS By setting the aspect ratio within the range of 2.5 to 10 and then heat-treating at a temperature in the austenite-ferrite two-phase region, the ferrite area fraction is reduced to 25 to 75%, and the remainder is martensite or bainite. machinability as a phase, and then subjected to aging treatment to obtain a HRC of 35 to 45,
A method for producing pre-hardened mold steel for plastic molding that has excellent toughness and specularity.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16549488A JPH0215117A (en) | 1988-07-01 | 1988-07-01 | Production of prehardened die steel for forming plastic |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16549488A JPH0215117A (en) | 1988-07-01 | 1988-07-01 | Production of prehardened die steel for forming plastic |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0215117A true JPH0215117A (en) | 1990-01-18 |
| JPH0456086B2 JPH0456086B2 (en) | 1992-09-07 |
Family
ID=15813466
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16549488A Granted JPH0215117A (en) | 1988-07-01 | 1988-07-01 | Production of prehardened die steel for forming plastic |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0215117A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104264060A (en) * | 2014-10-23 | 2015-01-07 | 山西百一机械设备制造有限公司 | High-impact toughness and high-thermal stability hot extrusion die steel and preparation method thereof |
| WO2023272873A1 (en) * | 2021-06-30 | 2023-01-05 | 江苏省沙钢钢铁研究院有限公司 | Plastic mold steel plate and production method therefor |
-
1988
- 1988-07-01 JP JP16549488A patent/JPH0215117A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104264060A (en) * | 2014-10-23 | 2015-01-07 | 山西百一机械设备制造有限公司 | High-impact toughness and high-thermal stability hot extrusion die steel and preparation method thereof |
| WO2023272873A1 (en) * | 2021-06-30 | 2023-01-05 | 江苏省沙钢钢铁研究院有限公司 | Plastic mold steel plate and production method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0456086B2 (en) | 1992-09-07 |
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