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轧制开坯钼丝退火点设置浅析 总被引:2,自引:0,他引:2
轧制开坯钼丝采用粉末生产的坯条或棒坯经轧制→旋锻→拉伸进行加工。因其具有变形均匀、单重大等优点,与传统旋锻开坯的钼丝相比,具有良好的加工性能和稳定性。但钼丝材的缺点是,在加工过程中易引起金属加工硬化,故生产中常出现断丝现象。轧制开坯钼丝拉伸加工较大规格时,上述现象更为突出,因此,须进行适当的退火,以消除应力,降低变形抗力,提高塑性。轧制开坯钼丝的简单工艺路线如右图所示。1 实验方法按以上工艺路线进行A、B两种工艺试验,如表1所示。其中A工艺在φ1.9 mm ~φ0.8mm拉伸工序中设置退火点,退火分别在φ1.4mm或… 相似文献
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采用800和960℃两种温度条件将Zr-4合金进行热轧开坯至2.2mm厚度,经中间退火后用带材轧机冷轧加工至1.2mm,再经过中间退火后冷轧成0.6mm厚的带材,研究轧制工艺对Zr-4合金带材织构取向因子的影响,并测试不同开坯温度制备的相同厚度的冷轧带材在400℃、10.3MPa过热蒸汽中72h的腐蚀性能。结果表明,相同冷轧加工率条件下,960℃热轧开坯所制备带材横向织构总是大于800℃热轧开坯所制备带材,而其法向织构总是小于800℃热轧开坯所制备的带材;相同热轧开坯温度条件下,冷轧加工率越大,横向织构越小,法向织构越大;经800℃热轧开坯制备的0.6mm厚的Zr-4合金带材的蒸汽腐蚀性能优于经960℃热轧开坯制备的Zr-4合金带材。讨论认为,可以在经济、稳定的工艺条件下相对精确地控制和计算Zr-4合金带的横向织构取向因子,但应关注工艺实施对成品带材腐蚀性能的影响。 相似文献
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金平安 《稀有金属材料与工程》1986,(2)
本文研究了钼粉的粒度、粒度组成、成型和烧结工艺参数对钼锭质量的影响以及烧结锭坯组织结构特征与性能的关系。同时,在提高烧结锭坯质量的基础上调整锻造开坯工艺参数,从而解决了锻坯表面微裂纹的现场问题,提高了钼板的质量与成材率。 相似文献
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文章通过控制TC11厚板材的轧制温度和开坯变形量,测试不同工艺板材的组织和力学性能,认为β单相区开坯的热态组织为理想的网篮组织,57.2%以上大变形量开坯是得到均匀网篮组织的关键。同时研究了轧制温度和变形量对TC11钛合金组织和性能的影响,经β相变点以上开坯61.2%大变形的TC11板材热态组织为均匀的网篮组织。退火后得到细小的双态组织,综合力学性能良好。成功研制出了激光成形基板用TC11钛合金厚板,为增材制造TC11钛合金大型复杂结构件奠定了基础,填补了国内TC11钛合金增材制造基板的研究和制造空白,推进了钛合金增材制造工业的发展。 相似文献
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Disk splats are usually observed when the deposition temperature exceeds the transition temperature, whereas thick oxide layer will reduce the adhesion resulting from high deposition temperature. In present study, single molybdenum splats were deposited onto polished molybdenum substrates with different preheating processes to clarify the effect of surface oxidation on the splat formation. Three substrate samples experienced three different preheating processes in an argon atmosphere. Two samples were preheated to 350 and 550 °C, and another sample was cooled to 350 °C after it was preheated to 550 °C. The chemistry and compositions of substrate surface were examined by XPS. The cross sections of splats were prepared by focus ion beam (FIB) and then characterized by SEM. Nearly disk-shaped splat with small fingers in the periphery was observed on the sample preheated to 350 °C. A perfect disk-shape splat was deposited at 550 °C. With the sample on the substrate preheated to 350 °C (cooling down from 550 °C), flower-shaped splat exhibited a central core and discrete periphery detached by some voids. The results of peeling off splats by carbon tape and the morphology of FIB sampled cross sections indicated that no effective bonding formed at the splat–substrate interface for the substrate ever heated to 550 °C, due to the increasing content of MoO3 on the preheated molybdenum surface. 相似文献
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It has been established that molybdenum sesquisulphide, not molybdenite, is in equilibrium with molybdenum metal and sulphur vapor in the vicinity of 1100°C. The S2 pressure for this system has been obtained using the Knudsen orifice method and the standard free energy for the dissociation of S2. 相似文献
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