【正文】 l parts of unparalleled strength and utility.在早期，鍛造是金屬通過加熱并錘打而成形的過程。對于超塑性流動特性完整的特征，但是，應(yīng)變誘導(dǎo)硬化的特性是必要的。在文獻(xiàn)中存在多種方法用于確定米，其中一些將在下面評論。通常選擇作為超塑性成形性質(zhì)的度量參數(shù)是在最佳超塑性溫度和應(yīng)變速率時的拉伸伸長率。由于加壓循環(huán)的成型過程中一個相當(dāng)精確的控制是必需的，這樣的要求并不限于確定最佳超塑性條件下的拉伸伸長率，且包括本構(gòu)RELA蒸發(fā)散的超塑性流動的詳細(xì)的表征。coolingroomandsteelof(hypereutectoidstructureafterbutmetalprocedureisinsolidintosolidandofbetakeandtheundercoolingcoolingandmorethethetemperatures. 淬火是加熱到臨界點(diǎn)以上,Ac3,隨后快速冷卻。transformationincreasingatintoslowbycriticalis加熱到Ac1以上但低于AC3,完全再結(jié)晶將不會發(fā)生并且該過程被稱為局部退火,退火鋼的狀態(tài)接近于結(jié)構(gòu)平衡狀態(tài)，其結(jié)構(gòu)是珠光體+鐵素體,珠光體或珠光體+滲碳體。orpearliteandstateisstatecalledandrecrystallizationbutWithandofa優(yōu)秀的防腐性能以及其他各種性能使這些金屬及其合金應(yīng)用非常昂貴。鉛的毒性限制了其設(shè)計應(yīng)用和合金處理。Lead alloys are durable and versatile materials. The lead pipes installed by the Romans at the public baths in Bath, England, nearly 2000 years ago are still in use. Lead’s high density and deformability bined with a low melting point adds to its versatility．Lead alloys find use in battery grids (alloyed with calcium or antimony), solders (alloyed with tin), radiation shielding，and sound control structures. The toxicity of lead restricts design applications and the handling of its alloys.鉛合金是耐用的多功能材料。Nickel exhibits excellent corrosion resistance and high temperature strength. Zinc alloys are ideally suited for die castings due to their low melting point and lack of corrosion reaction with steel crucibles and dies. Automobile parts and hardware are typical structural applications. Zinc coatings on ferrous alloys are important means of corrosion protection. This method is termed as galvanization鎳有優(yōu)良的腐蝕性和高溫強(qiáng)度。Cu－Ni合金已是典型的完全固溶例子。銅合金的廣泛應(yīng)用使其描述詞語選擇時經(jīng)?；煜?yōu)良的熱導(dǎo)率使其應(yīng)用于散熱器和熱交換器上。與鎂合金一樣，鈦合金也是Hcp晶格結(jié)構(gòu)，延展性低。其表面形成致密的氧化膜，使其就有優(yōu)良的抗腐蝕性。鋁合金是面心立方結(jié)構(gòu)金屬，因此，有12個滑移系，使其延展性好。電導(dǎo)率、易加工以及好的外觀也是其具有吸引力的特征。 AlloysAlthough ferrous alloys ale used in the majority of metallic applications in current engineering designs，non—ferrous alloys play a large and indispensable role in our technology. As pared to ferrous alloys，the list of non—ferrous alloys is，of course，long and plex．We shall briefly list the major families of non—ferrous alloys and their key attributes．盡管現(xiàn)代工業(yè)設(shè)計中，鐵合金是主要應(yīng)用的金屬，但是非鐵合金在當(dāng)前科技中也起著很大并不可替代的作用。一些合金元素偶爾會出現(xiàn)，其含量受限制。C: If a steel is to be welded．the user wants to know the position of the steel．since it determines the properties of the metal in the zone subjected to thermal effect of weld（焊接熱影響區(qū)）．The user is also interested in the initial mechanical properties of the metal，since these properties will remain the same in portions not subjected to welding．In that case the metal is delivered with warranted position and mechanical properties.C．如果鋼要進(jìn)行焊接，則用戶需要知道鋼的成分，因為成分決定鋼焊接時熱影響區(qū)的性能。這種情況下，用戶只需要求材料應(yīng)有的機(jī)械性能，而不必保證其成分。材料成型級控制工程專業(yè)英語閱讀 Plain Carbon Steel 普通碳鋼Hotrolled steel delivered （供給）by steelmaking works as rolled sections(bars, beams，sheets．tubes，etc) is the most wildly used material for manufacture of various machines，machine tools, building structures，consumer goods，etc．Delivered steel should have the properties as specified by State Standards（國家標(biāo)準(zhǔn)）．鋼鐵制造車間供給的熱軋鋼主要為棒材、柱材、板材、管材等，熱軋鋼是制造各種機(jī)械、機(jī)器工具、建筑結(jié)構(gòu)和消費(fèi)品中應(yīng)用最廣泛的材料。A: If a steel is to be used for making products without hot working (welding, Forging．Etc.). Its structure and properties in the final product will be the same as delivered from the rolling mill．In that case the user requests for a steel of warranted（保證） mechanical properties，while the chemical position is not guaranteed（保證、擔(dān)保）．A:如果鋼在制造產(chǎn)品的過程中沒有進(jìn)行熱加工（焊接、鍛造等），則最終產(chǎn)品的組織和性能將與軋廠提供的相同。因此，提供給用戶的鋼應(yīng)保證其成分含量。Generalpurpose plain steels are not alloyed．Some alloying elements may sometimes be present in them occasionally and their content（