本文選題：H13鋼　切入點(diǎn)：稀土Ce　出處：《內(nèi)蒙古工業(yè)大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：H13(4Cr5Mo Si Vl)鋼的碳含量雖然僅為0.37~0.42%,但因其合金含量較高使共析成分點(diǎn)左移成為過共析鋼,屬于高碳高鉻類過共析鋼。H13熱作模具鋼具有良好的淬透性、紅硬性、較高的韌性以及良好的高溫性能。但在鋼的凝固過程中,合金元素偏析嚴(yán)重,形成大量粗大的共析碳化物,嚴(yán)重降低了鋼的強(qiáng)韌性。因此,細(xì)化晶粒,減少碳化物,改變碳化物形態(tài)是提高H13鋼綜合性能的有效途徑。本文研究了添加稀土Ce對(duì)H13鋼性能的影響。稀土Ce加入H13鋼后,凈化了晶界,改變了夾雜物的形態(tài),有效的控制了鋼中夾雜物的大小與數(shù)量。當(dāng)鋼中稀土Ce含量過多時(shí),會(huì)產(chǎn)生大量稀土夾雜物,降低了H13鋼的耐磨性能及力學(xué)性能。隨著鋼中稀土含量的增加,H13鋼的耐磨性能逐漸提高,但是當(dāng)稀土含量超過0.35%時(shí),鋼的耐磨性能有所下降,當(dāng)鋼中稀土Ce的質(zhì)量分?jǐn)?shù)為0.35%時(shí),H13鋼可獲得最佳的耐磨性能。添加適量稀土Ce可有效的細(xì)化晶粒、減少夾雜及凈化晶界,顯著的提高H13鋼的強(qiáng)度和塑性,當(dāng)鋼中稀土Ce的質(zhì)量分?jǐn)?shù)為0.35%時(shí),H13鋼可獲得最佳的綜合力學(xué)性能。熱處理表明,為達(dá)到H13鋼強(qiáng)韌兼?zhèn)涞男阅?取最佳稀土Ce添加量試樣的最佳熱處理工藝為1035℃淬火,580℃第一次回火,560℃第二次回火,每次回火時(shí)間為2h。與其他熱處理工藝相比組織晶粒得到明顯細(xì)化,成分更均勻,耐磨性更好。經(jīng)過鍛造處理后,H13鋼的晶粒得到明顯細(xì)化,碳化物明顯減少,表明普通的鑄造工藝配合稀土Ce及熱處理難以取代鍛造工藝。
[Abstract]:Although the carbon content of H13C4Cr5MoSiVL) steel is only 0.370.42, the eutectoid composition point is shifted to hypereutectoid steel because of its high alloy content, which belongs to high carbon and high chromium hypereutectoid steel .H13 hot working die steel has good hardenability, red hardness, and high hardness. High toughness and good high temperature properties. However, during solidification of steel, alloy elements segregate seriously, forming a large number of coarse eutectoid carbides, which seriously reduces the strength and toughness of the steel. It is an effective way to improve the comprehensive properties of H13 steel by changing the carbide morphology. The effect of adding rare earth ce on the properties of H13 steel is studied in this paper. After adding rare earth ce to H13 steel, the grain boundary is purified and the shape of inclusions is changed. The size and quantity of inclusions in steel are effectively controlled. When the amount of rare earth ce in steel is too high, a large amount of rare earth inclusions will be produced. The wear resistance and mechanical properties of H13 steel were reduced. The wear resistance of H13 steel gradually increased with the increase of rare earth content, but the wear resistance of H13 steel decreased when the rare earth content exceeded 0.35. When the mass fraction of rare earth ce in steel is 0.35, the best wear resistance of H13 steel can be obtained. The addition of proper amount of rare earth ce can effectively refine the grain, reduce inclusions and purify grain boundaries, and significantly improve the strength and plasticity of H13 steel. The optimum comprehensive mechanical properties of H13 steel can be obtained when the mass fraction of rare earth ce in steel is 0.35. The heat treatment shows that in order to achieve the properties of both strength and toughness of H13 steel, The optimum heat treatment process of adding rare earth ce sample is 1035 鈩，

本文編號(hào)：1638324