稀土Ce对H13钢组织和力学性能的影响

发布时间：2018-03-20 08:42

  本文选题：H13钢　切入点：稀土Ce　出处：《内蒙古工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：H13(4Cr5Mo Si Vl)钢的碳含量虽然仅为0.37~0.42%,但因其合金含量较高使共析成分点左移成为过共析钢,属于高碳高铬类过共析钢。H13热作模具钢具有良好的淬透性、红硬性、较高的韧性以及良好的高温性能。但在钢的凝固过程中,合金元素偏析严重,形成大量粗大的共析碳化物,严重降低了钢的强韧性。因此,细化晶粒,减少碳化物,改变碳化物形态是提高H13钢综合性能的有效途径。本文研究了添加稀土Ce对H13钢性能的影响。稀土Ce加入H13钢后,净化了晶界,改变了夹杂物的形态,有效的控制了钢中夹杂物的大小与数量。当钢中稀土Ce含量过多时,会产生大量稀土夹杂物,降低了H13钢的耐磨性能及力学性能。随着钢中稀土含量的增加,H13钢的耐磨性能逐渐提高,但是当稀土含量超过0.35%时,钢的耐磨性能有所下降,当钢中稀土Ce的质量分数为0.35%时,H13钢可获得最佳的耐磨性能。添加适量稀土Ce可有效的细化晶粒、减少夹杂及净化晶界,显著的提高H13钢的强度和塑性,当钢中稀土Ce的质量分数为0.35%时,H13钢可获得最佳的综合力学性能。热处理表明,为达到H13钢强韧兼备的性能,取最佳稀土Ce添加量试样的最佳热处理工艺为1035℃淬火,580℃第一次回火,560℃第二次回火,每次回火时间为2h。与其他热处理工艺相比组织晶粒得到明显细化,成分更均匀,耐磨性更好。经过锻造处理后,H13钢的晶粒得到明显细化,碳化物明显减少,表明普通的铸造工艺配合稀土Ce及热处理难以取代锻造工艺。
[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，

本文编号：1638324