17-4PH钢连续加热奥氏体化的动力学

研究了17-4PH钢连续加热条件下的相变行为。结果表明,17-4PH钢在连续加热条件下,相变临界点Ac1、Ac3都随加热速率的加大而提高,转变温区也相应向高温扩展。奥氏体转变量与温度的关系呈S形,转变速率df/dt非定值且存在一个峰值。通过Kissinger法计算,确定17-4PH不锈钢的奥氏体化相变激活能为47.3kJ/mol。     

日本开发高强度高韧性不锈钢——HSL180

日本白立金属公司开发了抗张强度比现有高强度不锈钢17-4PH、15-5PH高，耐蚀性比超高强度锕1340，300M优异与17-4PH钢相当且韧性高。     

17—4PH不锈钢断裂原因分析

本文通过对17-4PH不锈铜的化学成分、高低倍金相组织及硬度检验，对其钢材破断的原因进行了分析和讨论。得知17—4PH不锈钢材质由于其硬度偏高韧性较差及其键槽设计欠妥是造成17—4PH不锈铜断裂的主要原因。     

EAF-VOD-2.5 t ESR-锻造流程生产Φ350 mm 17-4PH不锈钢

采用EAF -VOD工艺冶炼17-4PH沉淀硬化不锈钢(%≤0.04C、16.20～16.50Cr、4.50～4.70Ni、3.30～3.40Cu、0.25～0.40Nb),铁模下铸Φ320 mm电极,并电渣重熔(ESR)成2.5 t(Φ510～550 mm)锭,经800 t液压机或5 t蒸汽锻锤生产17-4PH钢Φ350 mm大规格锻材成品.工艺实践表明,控制停锻温度(蒸气锤980 ℃;液压机1050 ℃),将锻成的Φ350 mm 17-4PH钢成品材返回至室式加热炉(1130～1150 ℃)均热,缓冷至(1050±10)℃均热后,炉冷至420 ℃,并及时在650 ℃退火,有效地消除了该钢锻后炸裂现象.     

增材制造17-4PH马氏体不锈钢研究进展

17-4PH马氏体不锈钢具有高强高韧以及耐腐蚀等优异性能,在航空航天、核能和民用工业等领域得到广泛的应用。增材制造技术通过离散堆积的制备方法,能够实现复杂异形零部件的成形,满足装备迭代的需求。综述了国内外增材制造17-4PH的研究成果,针对增材制造微小熔池、快速熔凝、复杂热历史冶金特点,介绍影响增材制造17-4PH试样致密度的因素,阐述其相构成、微观组织和力学性能,简述后处理对17-4PH力学性能的影响规律,最后对增材制造17-4PH的发展进行展望。     

沉淀硬化不锈钢耐蚀抗磨性能的研究

用失重法测定了沉淀硬化不锈钢17-4PH在硫酸、石英砂固液两相介质中的腐蚀磨损速率,研究了介质浓度、冲刷速度和冲刷时间对17-4PH耐蚀抗磨性能的影响规律.试验结果表明,介质浓度越高、冲刷速度越大,17-4PH腐蚀磨损失重越大;而随着冲刷时间间隔的延长,腐蚀磨损失重越小.     

17-4PH马氏体沉淀硬化不锈钢表面防护技术研究进展

17-4PH马氏体沉淀硬化不锈钢具有良好抗衰减性能、抗腐蚀和抗空蚀性能以及优异的力学性能,在核能、海洋和航天等工业领域有广泛应用。由于长期服役于高温、腐蚀、冲击和摩擦的复杂环境中,17-4PH零部件表面受到水蚀、空蚀、腐蚀和摩擦磨损等严重破坏,亟需开展针对性防护研究。为此综述了目前17-4PH不锈钢表面防护的研究进展,主要从表面强化、表面改性和表面涂敷3个角度分析其优缺点、应用现状,并对其未来发展趋势进行展望。     

17-4PH马氏体沉淀硬化不锈钢表面防护技术研究进展

17-4PH马氏体沉淀硬化不锈钢具有良好抗衰减性能、抗腐蚀和抗空蚀性能以及优异的力学性能,在核能、海洋和航天等工业领域有广泛应用。由于长期服役于高温、腐蚀、冲击和摩擦的复杂环境中,17-4PH零部件表面受到水蚀、空蚀、腐蚀和摩擦磨损等严重破坏,亟需开展针对性防护研究。为此综述了目前17-4PH不锈钢表面防护的研究进展,主要从表面强化、表面改性和表面涂敷3个角度分析其优缺点、应用现状,并对其未来发展趋势进行展望。     

17—4PH马氏体沉淀硬化不锈钢的生产工艺探讨

17—4PH 钢是属於马氏体沉淀硬化不锈钢,它是美国 ARMCO 钢公司在1949年发表的,其特点是强度高,耐蚀性好,易焊接,热处理工艺简单,缺点是延韧性和切削性能差,这种马氏体不锈钢与靠间隙元素碳强化的马氏体钢不同,它除靠马氏体相变外并在它的基体上通过时效处理析出金属间化合物来强化。正因为如此而获得了强度高的优点,但延韧性却差。     

钢铁中痕量硒的催化极谱测定

PH10.3～10.5的HClO_4—Na_2SO_3—NH_4Cl—NH_4OH—EDTA-动物胶-KIO_4体系中,硒于-0.8伏左右产生一个非常灵敏的催化波,方法的基本条件及其机理已有报导.本文将此法应用于钢铁中微量硒的测定.拟定在盐酸:高氯酸:水=3:2:1的介质中,以抗坏血酸还原重铬酸根等氧化剂,用三氯甲烷萃取硒的溴化物,使硒有效地与铁及其它元素分离.本法适用于MnNiCrB钢、10PNbVTiZr钢、硅钢及其生铁中10~(-6)%硒的测定.方法的相对标准偏     

Effect of Aging Temperature on Erosion-Corrosion Behavior of 17-4PH Stainless Steels in Dilute Sulphuric Acid Slurry

The effect of aging temperature on erosion corrosion （E-C） behavior of 17-4PH stainless steels in dilute sulphuric acid slurry containing solid particles was studied by using self-made rotating E-C apparatus. The effect of impact velocity on EC behavior of 17 4PH steels at different aging temperatures was analyzed. Surface micrographs of the specimens after E C test were observed by using scanning electron microscope （SEM）. The results showed that under the condition of the same solution heat treatment, when aging temperature ranged from 400 ℃ to 610℃, the hardness reached the highest value near the temperature 460℃. The characteristics of E-C for 17-4PH stainless steels at different aging temperatures were as follows： pure erosion （wear） was dominant, corrosion was subordinate and at the same time corrosion promoted erosion. The effect of aging temperature on E-C rate of 17-4PH steels was not significant at low impact velocity, but it was found that E-C resistance of 17-4PH steels aged near 460℃ was the most excellent due to the best precipitation strengthening effect of fine and dispersed e-Cu phase. With a prerequisite of appropriate corrosion resistance, the precipitation hardening could significantly improve the E-C resistance of the materials.     

17-4PH无缝管制管技术的研究

17-4PH是美国开发研制的马氏体沉淀硬化型不锈钢,对应的中国牌号为0Cr17Ni4Cu4Nb,本钢种的无缝钢管生产的关键是:热穿孔加热温度范围较窄,且热穿孔后管内存在较强的内应力,应马上进行热处理。冷加工时打头后也应马上进行热处理。在加工过程中,17-4PH处于不同状态,其耐腐蚀能力也不同,应采用不同的酸洗工艺。钢管通过采用不同的热处理工艺可得到所需的再加工性能和成品的使用性能。     

选择性激光熔化成形17–4PH不锈钢研究

选择性激光熔化技术具有一次成形、节省原材料、可成形任意复杂结构工件及性能优良等特点，是17–4PH不锈钢成形研究的新方向。本文综述了近几年选择性激光熔化制备17–4PH不锈钢研究现状，包括工艺参数对17–4PH不锈钢性能的影响，热处理和热等静压对17–4PH不锈钢力学性能的改善，不同成形方式和不同后处理17–4PH不锈钢的显微组织变化，以及在选择性激光熔化成形17–4PH不锈钢过程中出现的问题和发展趋势。     

17-4PH金属注射成形(MIM)材料缺陷的实验分析

研究了注射成形生坯厚度与缺陷产生的临界升温速度的关系。实验结果证明,热脱粘缺陷主要表现为开裂缺陷与气泡孔缺陷。注射成形时生坯中所形成的气孔和粘结剂中高分子聚合物组元热解产生的气孔是造成缺陷的主要原因。MIM17-4PH烧结坯中残留的微孔隙使制品难以完全致密化,并造成缺陷。采用溶剂萃取-热解二步脱粘工艺达到了无缺陷脱粘的目的。     

金属注射成形不锈钢

介绍了金属注射成形(MIM)不锈钢的工艺及其性能。其中包括注射成形用不锈钢粉末的制取方法;采用水溶性粘结剂或催化脱粘法制取MIM316L不锈钢的工艺;MIM304L和17-4PH不锈钢的制取工艺及其性能     

Effect of plasma nitriding parameters on corrosion performance of 17-4 PH stainless steel

This study investigates the effect of plasma nitriding parameters on corrosion susceptibility of 17-4 PH stainless steel in 3.5?wt-% NaCl solution. In this regard, 17-4 PH stainless steel was plasma nitrided at 400°C for 5 and 10?h, 450°C for 5?h and 500°C for 5?h. Cross-sectional images after nitriding process showed that a uniform nitrided layer has been formed on steel substrate. Depending on the temperature and time of the nitriding process, different phases were formed in the nitrided layer. This affected general corrosion and pitting corrosion performance of 17-4 PH stainless steel in 3.5?wt-% NaCl solution. While precipitation of chromium nitrides for nitrided specimens at 450°C and higher increased the susceptibility to pitting and general corrosion, formation of expanded martensite (EM) in nitriding at 400°C improved the pitting corrosion resistance of 17-4 PH stainless steel. This is believed to be due to the release of nitrogen atoms from EM phase to form ammonium ions and increase the pH of the solution, supressing pit growth.     

Microstructure characteristics of segregation zone in 17-4PH stainless steel piston rod

The segregation of Cu and Ni in a 17-4PH stainless steel piston rod has been confirmed to be responsible for the cracking after heat treatment.Further investigation showed that the segregation zone was composed of three layers,namely the fine grain martensitic layer,the coarse grain martensitic layer and the coarse grain austenitic layer from the matrix to the crack surface.Three button ingots with the same chemical compositions as those three layers have been prepared to evaluate the grain size distribution,microstructure and mechanical properties.The effects of Cu and Ni segregation on the microstructures of those three layers have been explored by thermodynamic calculation.Based on the microstructure and mechanical properties results,an intensive understanding of the cracking in the segregation zone was therefore reached.