發(fā)展非調(diào)質(zhì)的大截面預(yù)硬塑料模具鋼外文翻譯

1、<p><b>　　中文2600字</b></p><p>　　畢業(yè)設(shè)計(jì)(論文)外文資料翻譯</p><p>　　學(xué) 院(系)： </p><p>　　專 業(yè)： </p><p>　　姓 名：

2、 </p><p>　　學(xué) 號(hào)： </p><p>　　外文出處： Development of Plastic Mould </p><p>　　附 件： 1.外文資料翻譯譯文；2.外文原文。 </p><p>　　注：請(qǐng)將該封面

3、與附件裝訂成冊。</p><p>　　附件1：外文資料翻譯譯文</p><p>　　發(fā)展非調(diào)質(zhì)的大截面預(yù)硬塑料模具鋼</p><p>　　LUO Yi,WU Xiao-chun,MIN Yong-an,ZHU Zhu,WANG Hong-bin</p><p>　?。ㄉ虾４髮W(xué)材料科學(xué)與工程學(xué)院，上海200072，中國）</p>

4、<p>　　摘要：為了滿足大截面預(yù)硬塑料模具鋼的需求和能源節(jié)約，一種非調(diào)質(zhì)預(yù)硬鋼正在發(fā)展。一個(gè)大型溫度場用有限元法研究和9號(hào)試驗(yàn)鋼在實(shí)驗(yàn)室中被設(shè)計(jì)。對(duì)它們的微觀結(jié)構(gòu)和硬度調(diào)查時(shí)用在空氣中冷卻和控制冷卻速度的類似的模擬冷卻。結(jié)果表明，硬度均勻的截面密切相關(guān)與預(yù)硬鋼的貝氏體淬透性，試驗(yàn)鋼的硬度在40到43洛氏硬度之間波動(dòng)在兩種冷卻條件下。該試驗(yàn)鋼比C45鋼具有更加良好的加工性能。預(yù)硬鋼成功的生產(chǎn)在工廠是基于實(shí)驗(yàn)室的結(jié)果。它的微觀結(jié)

5、構(gòu)是貝氏體，在尺寸為460毫米×800毫米×3200毫米上均勻分布。</p><p>　　關(guān)鍵詞：預(yù)硬鋼；大截面塑料模具；溫度估計(jì)；化學(xué)成分；微觀結(jié)構(gòu)；可加工性。</p><p>　　生產(chǎn)上的強(qiáng)烈增長和塑料的消耗已經(jīng)影響了塑料模具鋼材市場而對(duì)良好性能的塑料模具鋼的需求越來越多。各種系列塑料模具鋼材適應(yīng)不同性能要求，例如：耐磨，高硬度，耐腐蝕，韌性，拋光性，纖維化性質(zhì)，可

6、焊性，可加工性。在現(xiàn)有塑料模具鋼材系列中，中低碳合金鋼，例如AISI P20中的DIN2738和718（瑞典牌號(hào)）長久以來一直被廣泛應(yīng)用著，因?yàn)樗鼈兊牧己玫木C合性能。P20系列通過調(diào)質(zhì)的形式從鋼鐵廠的模具生產(chǎn)商生產(chǎn)出來，模具已加工后不需要進(jìn)行進(jìn)一步熱處理。它通常被稱為調(diào)質(zhì)預(yù)硬塑料模具鋼。預(yù)硬塑料模具鋼的優(yōu)勢在于模具制造它沒有失真的風(fēng)險(xiǎn)，可直接投入運(yùn)營。然而，調(diào)質(zhì)預(yù)硬鋼過程復(fù)雜和高能源消耗。在規(guī)模的塑料行業(yè)中，傳統(tǒng)的塑料模具QP鋼有時(shí)可能

7、沒有完全淬火或者淬火出現(xiàn)裂紋當(dāng)它們被用于大的塑料模具時(shí)[1,2]。因此，探討非調(diào)質(zhì)預(yù)硬塑料模具鋼為了避免上述的技術(shù)和經(jīng)濟(jì)缺點(diǎn)[3]。早在20世紀(jì)90年代，150毫米截面的調(diào)質(zhì)預(yù)硬塑料模具鋼（FT系列）被開發(fā)[4]。在最近十年里，B系列鋼誕生和部分代替了低于300毫米截面的P20鋼[5]。</p><p>　　實(shí)踐表明，該非調(diào)質(zhì)過程也可以生產(chǎn)出具有相似的，統(tǒng)一的硬度比的QP塑料模具鋼，同時(shí)減少生產(chǎn)周期和耗能。本文主

8、要研究大于300毫米截面的預(yù)硬塑料模具鋼，特別關(guān)注成分設(shè)計(jì)和滿足需求的大截面塑料模具鋼</p><p><b>　　實(shí)驗(yàn)過程</b></p><p>　　在冷卻條件上有很大的差別就是小尺寸試驗(yàn)鋼生產(chǎn)在實(shí)驗(yàn)室里而大截面硬鋼生產(chǎn)在工廠，大截面預(yù)硬鋼將通過微觀結(jié)構(gòu)和性能與試驗(yàn)鋼比較區(qū)別在相似的冷卻條件下。實(shí)驗(yàn)過程如圖1所示。</p><p>　　圖1

9、. 預(yù)硬鋼的發(fā)展進(jìn)程</p><p>　　9號(hào)試驗(yàn)鋼被冶煉在250公斤的感應(yīng)爐里，其化學(xué)成分（質(zhì)量分?jǐn)?shù)，%）顯示在表1里。每個(gè)試驗(yàn)鋼被鍛造直徑80毫米，然后用兩種方式冷卻:空氣冷卻和沙子冷卻。切斷樣品做硬度測試和顯微組織觀察，尺寸大小為80毫米×10毫米。每個(gè)樣品的硬度與洛氏硬度測定在核心到表面每5毫米處進(jìn)行，它們的組織在一個(gè)尼康LV150光學(xué)顯微鏡下被觀察。拉伸樣品從在空氣冷卻中的樣品中獲得。<

10、/p><p>　　機(jī)械加工性能在切削試驗(yàn)中進(jìn)行了評(píng)估通過測量切削力及切削刀具磨損，分別比較80毫米×320毫米的8號(hào)試驗(yàn)鋼和80毫米×310毫米的C45號(hào)鋼，后者淬火為10%的氯化鈉和回火。切削刀具是硬質(zhì)合金刀具YT15化學(xué)成分（質(zhì)量分?jǐn)?shù)，%）是79WC，15TiC,6Co,它的新優(yōu)勢被用于各項(xiàng)測試中。當(dāng)進(jìn)給速度定為0.1mm，切削深度改為0.5mm到0.3mm每0.5mm，主切削力被壓電式力測量

11、，切削速度分別在39m∕min和78.5m∕min,在刀具磨損測定中使用了精度為0.01毫米的工具制造商的顯微鏡。當(dāng)進(jìn)給速度和切削深度固定在0.1mm∕r和1.5mm時(shí)，分別首次消減60分鐘的切削速度19.6m∕min再消減35分鐘的切削速度34m∕min在刀具后刀面磨損實(shí)驗(yàn)中。</p><p>　　表1.測試鋼的化學(xué)成分</p><p>　　2. 討論和結(jié)果</p>&

12、lt;p>　　2.1 對(duì)大斷面預(yù)硬鋼冷卻速度的模擬</p><p>　　預(yù)硬鋼對(duì)塑料模具來說期望很大，然而它的冷卻速度減慢由于它的尺寸增大。對(duì)于大小為460毫米×800毫米×3200毫米的鋼，就必須知道它的溫度場，它可以適當(dāng)?shù)闹笇?dǎo)淬透性合金設(shè)計(jì)。簡言之，如果核心和表面的空氣冷卻速度是已知的，以及相應(yīng)的試驗(yàn)鋼的微觀的兩個(gè)冷卻速度相似，大斷面預(yù)硬鋼的硬度將分布均勻。</p>

13、<p>　　在圖2上的曲線B和曲線C通過有限元模擬分別反映了再核心和邊緣的大致溫度。這些估計(jì)的冷卻速率提供了參考依據(jù)為選擇合適的淬透性預(yù)硬鋼。對(duì)上述最快最慢的冷卻速率物理模擬，當(dāng)鍛造后冷卻速率的控制和空氣冷卻時(shí)，鋼的測試溫度被測量用K型電熱偶。測量的溫度顯示為曲線A和曲線D。由于潛熱是沒有考慮到有限元模擬，輻射發(fā)射表面系數(shù)可能會(huì)有所不同，在實(shí)際的冷卻條件下，控制的冷卻速率低于被估計(jì)的核心的冷卻速率。此外，鍛壓后測試鋼在空氣中冷

14、卻的冷卻速率快于表面的估計(jì)速率。根據(jù)這一點(diǎn)，控制冷卻率和空氣冷卻率的范圍比估計(jì)的冷卻速率大。結(jié)合460毫米×800毫米×3200毫米塊的有限元模擬和試驗(yàn)鋼的物理模擬，微觀結(jié)構(gòu)，核心和表面的特性可以比較控制冷卻速率的測試鋼和空氣冷卻的測試鋼。</p><p>　　圖2.測量的冷卻曲線和模擬的冷卻曲線</p><p>　　2.2 化學(xué)成分設(shè)計(jì)</p><

15、;p>　　當(dāng)預(yù)硬塑料模具鋼從模具型腔到制造，其內(nèi)側(cè)為工作面，這意味著它應(yīng)該有一個(gè)統(tǒng)一的硬度標(biāo)準(zhǔn)。因此，淬透性和整個(gè)截面硬度均勻在預(yù)硬鋼中發(fā)揮了重要的作用[6]。由于傳統(tǒng)的預(yù)硬鋼在淬火冷卻的熱處理過程中，在一般情況下硬度均勻性與馬氏體淬透性密切相關(guān)[7]。然而鍛造后，熱量與表面的空氣轉(zhuǎn)換慢得多比淬火，大截面預(yù)硬塑料模具鋼很難獲得馬氏體在整個(gè)截面中。但是，如果多邊形鐵素體轉(zhuǎn)變阻礙貝氏體相變發(fā)生在整個(gè)截面中，預(yù)硬鋼硬度可能會(huì)略有不同。預(yù)

16、硬鋼的淬透性在本文中被稱為貝氏體淬透性。</p><p>　　盡管對(duì)于淬火鋼來說碳是一個(gè)簡單又傳統(tǒng)的元素，過量的二氧化碳焊接明顯有害而且可能影響可加工性。由于這一點(diǎn)，碳含量必須在0.18%到0.31%之間。鉬能延緩高溫多邊形鐵素體轉(zhuǎn)化效率而對(duì)貝氏體相變的影響不大。特別是“0.5Mo-B”設(shè)計(jì)在低碳素鋼中可以得到充分的貝氏體結(jié)構(gòu)在一個(gè)很大的冷卻速度范圍內(nèi)[8]。鉬含量在0.1%到0.5%之間應(yīng)該考慮增加其他合金元素

17、以延緩過冷奧氏體的轉(zhuǎn)變。錳，鉻也可以增加來增加淬透性，因?yàn)樗鼈兛梢蕴峁┳罡叩腂S溫度和最低的MS溫度，它們具有良好的焊接性。釩已經(jīng)被選定為控制奧氏體晶粒長大，它的含量為0.1%。</p><p><b>　　工廠試制預(yù)硬鋼</b></p><p>　　根據(jù)8號(hào)鋼，預(yù)硬鋼鍛造后尺寸為460毫米×800毫米×3200毫米。硬度測定20毫米沿460毫米和

18、800毫米的方向分開，它徘徊在37到40洛氏硬度之間。貝氏體的顯微結(jié)構(gòu)無論是在核心和表面上看，并沒有出現(xiàn)大規(guī)模的鐵氧體，如圖3所示。</p><p>　?。╝）表面 （b）核心</p><p>　　圖3. 預(yù)硬鋼的顯微結(jié)構(gòu)</p><p><b>　　4 結(jié)論</b></p>&l

19、t;p>　　核心和表面的冷卻速度被估計(jì)用有限元模擬和物理模擬在實(shí)驗(yàn)室，它提供的數(shù)據(jù)來選擇預(yù)硬鋼的淬透性。</p><p>　　具有良好的貝氏體淬透性鋼從實(shí)驗(yàn)室中的9號(hào)試驗(yàn)鋼中選擇，它的化學(xué)成分是0.27C-1.95M-1.04Cr-0.45Mo-0.1V。它比C45鋼具有更好的切削性能[9]。</p><p>　　預(yù)硬鋼成功的生產(chǎn)在工廠是根據(jù)實(shí)驗(yàn)室里產(chǎn)生的8號(hào)鋼為基礎(chǔ)的。它的組織是貝

20、氏體，它的硬度在37到40洛氏硬度之間在尺寸為460毫米×800毫米×3200毫米的模具上。</p><p><b>　　參考文獻(xiàn)：</b></p><p>　　[1] CHEN Zai-zhi,MA Dang-shen.Plastic Mould Steel Application Manual[M].</p><p>　

21、　Beijing:The Chemistry Industry Press,2005(in Chinese)</p><p>　　[2] LUO Yi , WU Xiao-chun. Research Progress of the Work on Prehardened Plastic</p><p>　　Mould Steel[J].Heat Treatment of Metals,2

22、007,32(12):22(in Chinese) .</p><p>　　[3] SONG Dong-li,GU Jian-feng,ZHANG Wei-min,etal.Numerical Simulation on</p><p>　　Temperature and Microst ructure DuringQuenching Process for Large-Sized<

23、/p><p>　　AISI P20 Steel Blocks Used as Plastic Die[J ].Transactions of Materials</p><p>　　and Heat Treatment,2004,25(5):740.</p><p>　　[4] WU Xiao-chun , ZHANGJie , CUI Kun. The Microst

24、 ructure and Mechanical</p><p>　　Properties of Unquenched and Untempered Die Steel for Plastic Mould [J ].</p><p>　　Journal of Huazhong University of Science and Technology ,1995 ,23(12):</p&

25、gt;<p>　　1(in Chinese)</p><p>　　[5] JIANG Lai-zhu ,WANGJiang-hui.Development of a Non-Quenched Non-Tempered </p><p>　　Bainitic Steel for Plastic Mould :Continuous Cooling Transformation &

26、lt;/p><p>　　Behavior[A].J eglit sch F,Ebner R,Leitner H ,eds.Proceedings of the 5th </p><p>　　International Conference on Tooling[C].Leoben:1999.685.</p><p>　　[6] SONG Dong-li,GU Jian-

27、feng,PAN Jian-sheng,etal.Design of Quenching Process</p><p>　　for Large-Sized AISI P20 Steel Block Used as Plastic Die[J].Journal of</p><p>　　Materials Science and Technology,2006,22(1):139.<

28、/p><p>　　[7] LIU Zhuang,WU Zhao-ji,WU Jing-zhi,etal.Numerical Simulation of Heat</p><p>　　Treatment[M].Beijing:Science Press,1996(in Chinese).</p><p>　　[8] Pickering F B. Physical Meta

29、llurgy and the Design of Steels[M].London: </p><p>　　Applied Science Publishers LTD,1978.</p><p>　　[9] Vetter P,Hippenstiel F.A New Pre-Hardened Plastic Mould Steel as a Tailored </p><

30、;p>　　Solution for Large Moulds[A].Rosso M,Actis Grande M,Ugues D,eds.</p><p>　　Proceedings of the 7th International Conference on Tooling[ C].Torino:</p><p><b>　　2006.317.</b><

31、/p><p>　　附件2：外文原文（復(fù)印件）</p><p>　　Development of Non-Quenched Prehardened Steel for Large Section Plastic Mould</p><p>　　LUO Yi , WU Xiao-chun ,MIN Yong-an , ZHU Zhu , WAN G Hong-bin<

32、/p><p>　　(School of Materrial Science and Engineering,Shanghai University,Shanghai 200072,China)</p><p>　　Abstract：In order to meet the demand of prehardened steel for large section plast ic mould

33、and save energy,a non –quenched prehardenedNQP steel is decelop. The temperature field of a large block is researched by finite element method simulation and 9 test steels are designed in the laboratory.Their microstruct

34、ures and hardness are investigated when they are air cooled and control cooled at cooling rate similar to the simulation.The result shows that the hardness uniformity through section is clo</p><p>　　Key word

35、s : NQP steel ; large section plastic mould ; temperature lestimation ; chemical composition ; microstructure ;machinability</p><p>　　The intensive increase in the production and consumption of plastics has

36、also influenced the plastic mould steel market with its demand for increasing amount s and good availability of plastic mould steels. Various serial plastic mould steels are developed to fit the different properties requ

37、irements , e.g1. wear resistance,hardness,corrosion resistance,toughness,polishabilit,texturizing properties , weldability , and machinability.For current plastic mould steel family , the medium carbon low a</p>&

38、lt;p>　　150 mm ( FT series ) was developed[4 ] . In recent years , B series steel was produced and partly instead of P20 steel with section size below 300 mm[ 5 ] .</p><p>　　Practice shows that the non-que

39、nching process can also produce plastic mould steel with similar and uniform hardness compared to QP steel , and can simultaneously reduce the production cycle and energy consumption. The present st udy developed an NQP

40、steel for plastic mould with section size larger than 300 mm , specially focusing on the composition design , and satisfying the demand of large-section plastic mould steel .</p><p>　　1 　Experimental Procedu

41、re</p><p>　　As big difference exist s in cooling condition between small size test steels produced in t he laboratory and the large section NQP steel produced in the factory , the NQP steel should be picked

42、out through microstructure and properties comparison of test steels controlled cooled at similar cooling condition of the large section NQP steel . The experimental procedure is shown in Fig.1.</p><p>　　1 　E

43、xperimental procedure</p><p>　　Nine test steel swere smelted in a 250 kg induction furnace , and their chemical compositions (mass percent , %) are shown in Table 2. Each test steel ingot was forged to Φ80 m

44、m bar , and then cooled in two different ways : air cooled and sand cooled.Samples were cut from bars for the hardness test and microstructure observation , and their size was Φ80 mm ×10 mm. The hardness of each sam

45、ple was measured with the Rockwell C hardness tester from it s core to surface every 5 mm , and their micros</p><p>　　The machinability was evaluated by measuring the cutting force and wear of the cutting t

46、ools in dry turning tests , and the test bars of No.8 steel and C45 steel for comparison were Φ80 mm ×320 mm andΦ80 mm ×310 mm , respectively , and the latter was quenched into 10 % NaCl and tempered. The cutti

47、ng tool was cemented carbide cutter YT15 whose nominal chemical composition (mass percent , %) was 79 WC ,15 TiC , and 6 Co , and its new edge was used in each test . When the feed rate was fixed at 0。1</p><p&

48、gt;　　every 0.5 mm , the main cutting force was measured by a piezoelectric force dynamometer at the cutting speed of 39 m/ min and 78.5 m/ min , respectively.The flank wear of tool was measured using a tool maker′s micro

49、scope with precision of 0.01 mm. When the feed rate and the cutting depth were fixed at 0.1mm/ r and 1.5 mm , respectively , two bars were first cut for 60 min at the cutting speed of 19.6 m/ min , and then cut for 35 mi

50、n at the cut ting speed of 34 m/ min in the experiment of the fla</p><p>　　Table 1 Chemical composition of test steels</p><p>　　2 Results and Discussion</p><p>　　2.1 Simulation

51、of the cooling rates of large section NQP</p><p>　　The NQP steel for plastic mould is expected to be as large as possible , while its cooling rate slows down with its size increasing. For the block with size

52、 460 mm ×800 mm ×3 200 mm (it is predesigned in the factory) , it is necessary to know it s temperature field , which can guide the alloy design with proper hardenability. Briefly speaking , if the core and sur

53、face cooling rate of air cooled block are known , and the corresponding microstructures of the test steel at both cooling rates are si</p><p>　　Curve B and curve C in Fig.2 show the estimated temperature at

54、core and edge in the block separately by FEM simulation. These estimated cooling rates provide the reference data to select the suitable hardenability for the NQP steel. For physically simulating above the slowest and fa

55、stest cooling rates ,the temperature of test steels was measured by the K-type thermocouple when cooled at cont rolled rate and air cooled after forging. The measured temperature is shown as curve A and curve D. As th<

56、;/p><p>　　rate is slower than that of the estimated cooling rate of the core. Furthermore , the cooling rate of test steels air cooled after forging is faster than that of the surface of the block estimated. Ac

57、cording to this , the scope of the controlled cooling rate and the air cooling rate is wider than that of the estimated cooling rate of the section in the block. Combined FEM simulation of 460 mm×800 mm×3 200 m

58、m block and</p><p>　　physical simulation of the test steels , microstructures , and properties at core and surface in the block can be compared by controlled cooled test steels and air cooled ones

59、 </p><p>　　2.2　Chemical composition design</p><p>　　When the prehardened steel for plastic mould is manufactured into the mould cavity , its interior side becomes

60、 the working surface , which means it should have a uniform level of hardness. Therefore , hardenability and hardness uniformity throughout the cross-section play an important part in prehardened steel[6 ] . Since conven

61、tional prehardened steel is cooled in quenchant during heat treatment , its hardness uniformity is closely correlated to the martensitic hardenability in several cases[7]</p><p>　　Though carbon is an easy an

62、d conventional element to harden steel , excessive carbon obviously impairs weldability and may affect the machinability.Owing to this , the carbon content must be around 0.18 %- 0.30 %. Molybdenum can retard high temper

63、ature polygonal ferrite transformation efficiently while have little influence on the bainite transformation. Especially , the“0.5Mo-B”design in the low carbon steel can obtain fully bainitic structures over a wide range

64、 cooling rate[8 ] . The molybdenu</p><p>　　Ms temperature , which is good for the weldability.Vanadium has been chosen to cont rol austenite grain growth , and its content is 0.1 %.</p><p>　　3 　

65、Factory Trial Production of NQP Steel</p><p>　　Based on the No.8 steel , the NQP steel was produced after forging. It s size was 460 mm×800 mm×3200 mm. The hardness was measured every 20 mm along t

66、he directions of 460 mm and 800 mm separately , and it fluctuated between HRC 37 and 40.The microstructures were bainite both in the core and surface , and no massive ferrite appeared(Fig.3)</p><p>　　Fig 3 M

67、icrostructures of NOP steel</p><p>　　4 　Conclusions</p><p>　　The cooling rates at core and surface of a block are estimated by FEM simulation and physical simulation in the laboratory , which pr

68、ovides the data to select the suitable hardenability for the NQP steel.</p><p>　　The steel with good bainitic hardenability is selected from the 9 test steels prepared in t he laboratory , whose chemical com

69、position is 0.27C-1.95Mn- 1.04Cr-0.45Mo-0.1V. It has better machineability compared with C45 steel [9].</p><p>　　The NQP steel is produced successfully in the factory based on the No.8 steel produced in the

70、laboratory. It s microstructure is bainite and its hardness fluctuates between HRC 37 and 40 in the 460 mm×800 mm×3200 mm mould.</p><p>　　References :</p><p>　　[ 1 ] 　CHEN Zai-zhi , MA

71、 Dang-shen. Plastic Mould Steel Application Manual [M] . Beijing : The Chemistry Industry Press ,2005 (in Chinese) .</p><p>　　[ 2 ] 　LUO Yi , WU Xiao-chun. Research Progress of the Work on Prehardened Plasti

72、c Mould Steel [J ] . Heat Treatment of Metals , 2007 , 32 (12) : 22 (in Chinese) .</p><p>　　[ 3 ] 　SONG Dong-li , GU Jian-feng , ZHANG Wei-min , et al . Numerical Simulation on Temperature and Microst ructur

73、e DuringQuenching Process for Large-Sized AISI P20 Steel Blocks Used as Plastic Die [J ] . Transactions of Materials and Heat Treatment , 2004 , 25 (5) : 740.</p><p>　　[ 4 ] 　WU Xiao-chun , ZHANGJie , CUI Ku

74、n. The Microst ructure and Mechanical Properties of Unquenched and Untempered Die Steel for Plastic Mould [J ] . Journal of Huazhong University of Science and Technology , 1995 , 23 (12) : 1 (in Chinese)</p><p

75、>　　[ 5 ] 　J IANG Lai-zhu , WANGJiang-hui . Development of a Non-Quenched Non-Tempered Bainitic Steel for Plastic Mould :Continuous Cooling Transformation Behavior [A] . J eglit sch F , Ebner R , Leitner H , eds. Proce

76、edings of the 5 th International Conference on Tooling [C] . Leoben : 1999. 685.</p><p>　　[ 6 ] 　SONG Dong-li , GU Jian-feng , PAN Jian-sheng , et al . Design of Quenching Process for Large-Sized AISI P20 St

77、eel Block Used as Plastic Die [J ] . Journal of Materials Science and Technology , 2006 , 22 (1) : 139.</p><p>　　[ 7 ] 　LIU Zhuang , WU Zhao-ji , WU Jing-zhi , et al . Numerical Simulation of Heat Treatment

78、[M] . Beijing : Science Press ,1996 (in Chinese) .</p><p>　　[ 8 ] 　Pickering F B. Physical Metallurgy and t he Design of Steels[M] . London : Applied Science Publishers LTD , 1978.</p><p>　　[ 9

79、] 　Vetter P , Hippenstiel F. A New Pre-Hardened Plastic Mould Steel as a Tailored Solution for Large Moulds [A] . Rosso M ,Actis Grande M , Ugues D , eds. Proceedings of t he 7t h International Conference on Tooling [ C]