Y元素对锻造热处理Ti-Fe-Mo合金显微组织及力学性能的影响

根据是否掺入Y元素设计两类样品,以空冷、炉冷工艺制备出钛合金烧结坯,通过室温拉伸试验,检验金相显微组织,以此来分析添加Y元素对Ti-Fe-Mo合金显微组织及力学性能的影响机制。结果表明:合金强度和塑性最佳匹配状态的退火温度为650℃,若高于β转变点温度,α相转为β相,受稀土氧化物颗粒影响,保留的β晶粒无法生长,尺寸约为80~100μm;Ti-Fe-Mo合金的室温拉伸强度和延伸率因添加YH_(2)后得到改善,拉伸强度相比未添加YH_(2)合金的样品高50~70 MPa。

锻造热处理工艺对Al-7Si-1.6Cu合金组织和力学性能的影响

通过力学性能测试以及OM、SEM和TEM的组织观察,研究了锻造热处理工艺对Al-7Si-1.6Cu合金组织与力学性能的影响。结果表明,合金经过均匀化(500℃,8h)、锻造(锻造温度380~450℃,应变速率60~90s-1,道次压缩比10%~20%)、热处理(固溶480℃,2h,70℃,水冷;时效180℃,6h)之后,较铸态相比硬度提高18%、抗拉强度提高了52%、延伸率提高了54.5%。多向锻造过程中共晶Si相发生碎断与球化,时效过程中析出的纳米级第二相对合金起强化作用。开创性地从位错密度方向解释锻造过程强度提高的原因,通过Zener-Hollomon参数来说明锻造过程中流变应力与变形速率和变形温度之间的关系。

Cr12MoV钢模具的热处理

阐述了Cr12MoV钢在制造模具过程中热处理的重要性,通过对Cr12MoV钢的锻造、锻造后的热处理及热处理前的预处理、最终热处理等方面介绍了Cr12MoV钢在制造模具时在热处理方面应注意的问题和经验,以保证Cr12MoV钢制造的模具,特别是容易变形、要求精度较高的模具热处理后能够满足模具图纸及技术需求。

Tensile properties and microstructure of Ti14 alloy after semi-solid forging

Tensile properties of a new α＋Ti2Cu alloy after solid forging at 950 °C and semi-solid forging at 1 000 °C and 1 050 °C were investigated over the temperature range of 20-600 °C. The results reveal that high strength and low ductility are obtained in all semi-solid forged alloys. Tensile properties decrease as the semi-solid forging temperature increases, and cleavage fractures are observed after semi-solid forging at 1 050 °C. The variations in tensile properties are attributed to the coarse microstructures obtained in the semi-solid alloys. It is found that the elevated semi-solid temperatures lead to more liquid precipitates along the prior grain boundaries, which increases the peritectic precipitation and formation of Ti2Cu precipitation zones during re-solidification. Recrystallization heat treatment leads to fine microstructure of semi-solid forged alloys, resulting in improvement of tensile properties.

Effect of duplex aging on microstructure and mechanical properties of near-βtitanium alloy processed by isothermal multidirectional forging

The effects of sub-transus(α+β)annealing treatment(ST),followed by single aging(SA)or duplex aging(DA)on the microstructural evolution and mechanical properties of near-βTi-4Al-1Sn-2Zr-5Mo-8V-2.5Cr(mass fraction,%)alloy were investigated using optical microscopy,scanning electron microscopy,and transmission electron microscopy.The results show that the finer secondaryαphase precipitates in the alloy after DA than SA(e.g.,149 nm for SA and 69 nm for DA,both after ST at 720℃).The main reason is that the pre-aging step(300℃)in the DA process leads to the formation of intermediateωphase nanoparticles,which assist in the nucleation of the acicular secondaryαphase precipitates.In addition,the strength of the alloy after DA is higher than that of SA at the specific ST temperature.A good combination is achieved in the alloy subjected to ST at 750℃,followed by DA(UTS:1450 MPa,EL:3.87%),which is due to the precipitation of nanoscale secondaryαphase by DA.In conclusion,DA is a feasible process for this new near-βtitanium alloy.

Microstructural evolution and mechanical properties of forgedβ-solidifiedγ-TiAl alloy by different heat treatments

The microstructural evolution and tensile properties of a forged Ti−42Al−5Mn alloy subjected to different heat treatments were studied.The results showed that,when the forged alloy was aged at 800℃ for 24 h,the interlamellar spacing(λ)andγgrain size at colony boundaries are generally coarsened.Whereas,when the alloy was first annealed at 1300℃ and then aged at 800℃ for 24 h,this coarsening of related microstructures appears less pronounced.The suggested annealing temperatures for the forged Ti−42Al−5Mn alloy are in the range of 1250−1300℃.It was found that,on the condition of the same annealing system,both the strength and ductility were improved as the aging temperature changed from 1000 to 800℃.The secondary precipitatedβo(β_(o,sec))at colony boundaries could be responsible for improving the strength,and theγphase at colony boundaries with the grain size about 6μm might be one of the main reasons for the better ductility.

Cooling slope casting to produce EN AW 6082 forging stock for manufacture of suspension components

The potential of cooling slope casting process to produce EN AW 6082 forging stock for the manufacture of EN AW 6082 suspension components was investigated.EN AW 6082 billets cast over a cooling plate offer a fine uniform structure that can be forged even without a separate homogenization treatment.This is made it possible by the limited superheat of the melt at the start of casting and the fractional solidification that occurs already on the cooling plate.Suspension parts forged from cast and homogenized billets with or without Cr all showed a umform structure,and the hardness reached HV 110 after the standard artificial ageing treatment.

Influence of forging and heat treatment on wear properties of Al-Si and Al-Pb bearing alloys in oil lubricated conditions

The tribological behaviours of aluminium-based bearing alloys with different compositions, forged and heat treated materials, were investigated in oil lubricated conditions. Tested materials were Al-8.5Si-3.5Cu and Al-15Pb-3.7Cu-1.5Si-1.1Fe. The effects of hardness, heat treatment and forging on wear behaviours of the tested materials were investigated. In forging process, 10%-20%strains were applied. Heat treatment （T6） was performed to the materials. The wear tests of all specimens were performed with a pin-on-disc wear test machine. Forging process increased hardness value of the tested materials. A forging strain of 10%-20%has no significant effect on mass loss.

Influence of T6 heat treatment on A356 and A380 aluminium alloys manufactured by thixoforging combined with low superheat casting

The effects of T6 heat treatment on thixoforged A356 and A380 aluminium alloys were studied.Low superheat casting(LSC)technique was carried out to prepare proper specimens for thixoforging process.The samples were poured at 20°C above their liquidus temperatures which provided the formation of equiaxed grains instead of dendritic growth.Produced billets were reheated for varied time from 20 to 80 min and thixoforged with 50%deformation rate.After thixoforging process,the samples were T6 heat treated for both A356 and A380 alloys.The microstructural evaluation and hardness alteration of thixoforged,solution treated and aged specimens were examined comparatively by using optical microscopy,scanning electron microscopy with energy-dispersive X-ray spectroscopy and Brinell hardness equipment.T6 heat treatment provided relatively uniform microstructure with newly formed precipitates that are Mg2Si and Al2Cu for A356 and A380 billets,respectively.Accordingly,hardness after artificial aging was increased considerably and reached HB 93 for A356 and HB 120 for A380 alloys.

Effect of T6-treatments on microstructure and mechanical properties of forged Al-4.4Cu-0.7Mg-0.6Si alloy

Transmission electron microscopy(TEM),scanning electron microscopy(SEM),hardness tests and tensile tests were performed to investigate the effect of aging on microstructure and mechanical properties of forged Al-4.4Cu-0.7Mg-0.6Si alloy.The results show that the alloy exhibits splendid mechanical properties with an ultimate tensile strength of504MPa and an elongation of10.1%after aging at170°C for16h.With tensile testing temperature increasing to150°C,the strength of the alloy declines slightly to483MPa.Then,the strength drops quickly when temperature reaches over200°C.The high strength of the alloy in peak-aged condition is caused by a considerable amount ofθ'and AlMgSiCu(Q)precipitates.The relatively stable mechanical properties tested below150°C are mainly ascribed to the stability ofθ'precipitates.The growth ofθ'and Q precipitates and the generation ofθphase lead to a rapid drop of the strength when temperature is over150°C.

接管锻件的质量控制

本文从设备监理的角度对接管锻件制造工作做了一个梳理,并对接管锻件制造过程中出现的质量问题进行了总结和简要分析,特别是对材料熔炼、非金属夹杂进行了分析,包括对标准的理解,对生产工艺、制造元素的解读,对国产新工艺、新技术的认知及对材料学专业基础的再学习,旨在提高接管锻件制造质量控制力度。

兰州石油化工机器厂

兰州石油化工机器厂是中国第一个五年计划期间建成的生产石油钻采机械和炼油化工设备的大型骨干企业。经过30多年的发展,如今已经成为国内规模最大的石油钻采机械和炼油化工设备的制造基地。工厂现有职工1.1万余人,拥有主要生产设备2100余台。 兰州石油化工机器厂下属压力容器分厂、钻采机械分厂和化工机械分厂,以及铸钢、铸铁、精铸、锻造热处理、橡胶、板式换热器。

锻锤轰鸣写人生——全国机械行业劳动模范李茂春的追求

李茂春同志现为兰州石油化工机器总厂锻造热处理厂总工程师。自1958年参加工作以来,一直从事锻造方面的工艺、模具设计及锻压机械设计工作,在不同时期、不同岗位,为兰石厂的锻造生产机械化、机电一体化、开发新产品,占有市场份额做出了突出贡献。 八十年代初,为了改变自由锻锤耗能高、效率低、劳动条件差的落后状况。

铁路车轴

铁路车轴是公司规模化经营的主导产品。20世纪70年代末,经国家有关部委批准同意,在某军品锻造热处理生产线基础上,总投资600万元,开始了车轴的开发和生产。1979年9月,第一批车轴顺利下线,成为当时国家重点“保军转民”项目中成果较大的一项。 “七五”至“九五”期间,为满足国内铁路运输事业飞速发展的需要,同时也为不断巩固“保军转民”的战略成果,先后累计投资2.3亿元分两期对车轴生产线进行了全面技术改造,形成了生产9万根的生产能力。截止目前。