共查询到20条相似文献,搜索用时 375 毫秒
1.
本文主要介绍了钛合金铸件使用的热等静压处理(HIP)及氢处理(THT)这两种热处理工艺对其显微组织和力学性能的影响以及工程应用。热等静压处理可以消除铸件内部的封闭孔洞,减少铸件缺陷。氢处理可以显著提高钛合金的拉伸、疲劳、持久等性能。 相似文献
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
介绍了低Si高Ni奥氏体球墨铸铁轴类铸件的铸造工艺,包括化学成分、炉料配比、球化剂、孕育及热处理工艺的选择。通过加入微量Sb消除了厚大件的碎块状石墨;选用冒口补缩并采用冷铁防止了缩孔缩松;采用铁液高温出炉、快速浇注的方法,消除了皮下气孔缺陷;等,得到了质量合格的出口铸件 相似文献
12.
Finite element simulation of real cavity closure in cast Ti6Al4V alloy during hot isostatic pressing
The healing behavior of shrinkage cavity inside the cast Ti6Al4V alloy during hot isostatic pressing(HIP)was investigated experimentally by interrupted hot isostatic pressing tests.The X-ray micro computed tomography was used to record the morphology changes before and after hot isostatic pressing.The two-dimensional geometry obtained by the microCT scan was used in simulation to study the evolution of the real shrinkage cavity during hot isostatic pressing.Shrinkage cavities,shrinkage porosity and small gas pores can be effectively eliminated under proper HIP conditions.The two-dimensional morphology in the simulation results agrees well with the experimental results.This study reveals that plastic deformation,creep and diffusion are the main mechanisms of cavity closure during hot isostatic pressing.In addition,the simplified elliptical pores with aspect ratios at different positions were used to replace the real pores to further study the factors affecting the position of dimples after HIP by simulation.It is found that the position of the dimples mainly depends on the aspect ratio of the elliptical pore and the distance between the pore surface and the external surface of the geometric model. 相似文献
13.
分析了2000MW级风电行星架大型铸钢件铸造生产过程中出现的缩孔缺陷的成因.提出了消除该类缺陷的几种主要工艺措施和方法:浇注位置的合理选择、浇注系统的优化设计、冒口系统的改进、冷铁的优化设置、浇注工艺的改进等措施.通过采用这些措施,有效地消除了铸件的缩孔缺陷. 相似文献
14.
The Ti6Al4V alloy castings were produced by the investment casting process, and the hot isostatic pressing(HIP) was used to remove shrinkage from castings. The processing pressure and holding time for HIP were 150 MPa and 20 min, respectively. Four different HIP temperatures were tested, including 750 ℃, 850 ℃, 920 ℃ and 950 ℃. To evaluate the effects of temperature on densification and microstructure of Ti6Al4V alloy treated by HIP, non-destructive testing and metallographic observation was performed. The experimental results show that the shrinkage was completely closed at 920 ℃ and 950 ℃. The densification of Ti6Al4V alloy increased as the HIP temperature increased below 920 ℃. The lamel ae were more uniform, the thickness of lamel ae was obviously broadened and the structure was coarsen. Besides, the Norton creep equation was used to simulate the effect of different temperatures on the densification of Ti6Al4V alloy during HIP. The simulation results were in good agreement with the experimental results. It was also found that 920 ℃ is a suitable temperature for HIP for Ti6Al4V alloy. 相似文献
15.
采用黏土湿型砂射压造型生产线,铸件存在缩松和硬度过高的缺陷.从浇注温度、冒口颈和碳当量对铸件缺陷的影响进行了分析,发现铁水高温保温时间过长造成碳烧损是引起铸件缺陷的主要原因.为减少铁水的碳烧损,随其保温时间延长添加增碳剂,铸件缩松和过硬的缺陷彻底消除,从而保证了铸件质量. 相似文献
16.
17.
首先对汽车差速器壳进行合理的铸造工艺方案设计,然后利用华铸CAE软件对球墨铸铁差速器壳的充型及凝固过程进行数值模拟.基于模拟结果,预测和分析在此工艺方案下铸件产生缩孔的倾向和形成原因,进而提出冒口补缩系统的优化方案,成功消除了差速器壳铸造过程中产生的缩孔缺陷.结果表明:利用CAE计算机模拟技术有助于为工艺方案的评估与优化提供可靠的借鉴,缩短了产品试制周期,降低废品率,保证了铸件质量. 相似文献
18.
厚实板类铸件按传统工艺生产,容易产生缩孔,缩凹,缩松,夹砂,胀包等铸造缺陷,应用均衡凝固理论进行工艺设计,能解决该类铸件上述缺陷,提高铸件质量和企业经济效益。 相似文献
19.
邹日荣 《特种铸造及有色合金》2005,25(3):191-192
分析了锡青铜叶轮铸件出现的缩孔、气孔、冲砂等缺陷的原因。采取改用冷硬树脂砂造型、安放冷铁和搞好生产过程的质量控制等措施,基本上消除了这些缺陷,获得了质量稳定的合格铸件。 相似文献
20.
使用华铸CAE模拟软件,对转架铸造的凝固过程进行了数值模拟,对比分析了原工艺产生缺陷的部位和原因。在此基础上,优化了铸造工艺。模拟分析显示,新工艺实现了转架的顺序凝固,消除了缩孔、缩松。生产实践表明,新工艺生产的转架内部组织致密,满足其技术要求。 相似文献