我国大型铸钢件生产的现状与关键技术

介绍了我国大型铸钢件行业的现状及与国外先进企业的差距,以水电、冶金等重点工程为例分析了未来5～10年中我国大型铸钢件的市场需求情况。详细介绍了大型铸钢件生产中材料冶炼、铸造工艺、热处理工艺及计算机数值模拟技术等关键技术及其在大型铸钢件生产中的应用情况。     

Advanced manufacturing technologies of large martensitic stainless steel castings with ultra low carbon and high cleanliness

The key manufacturing technologies associated with composition,microstructure,mechanical properties,casting quality and key process control for large martensitic stainless steel castings are involved in this paper.The achievements fully satisfied the technical requirements of the large 700 MW stainless steel hydraulic turbine runner for the Three Gorges Hydropower Station,and become the major technical support for the design and manufacture of the largest 700 MW hydraulic turbine generator unit in the world developed through our own efforts.The characteristics of a new high yield to tensile strength (Rp0 2/Rm) ratio and high obdurability martensitic stainless steel with ultra low carbon and high cleanliness are also described.Over the next ten years,the large martensitic stainless steel castings and advanced manufacturing technologies will see a huge demand in clean energy industry such as nuclear power,hydraulic power at home and abroad.Therefore,the new high yield o tensile strength (Rp0.2/Rm) ratio and high obdurability martensitic stainless steel materials,the fast and flexible manufacturing technologies of large size castings,and new environment friendly sustainable process will face new challenges and opportunities.     

数值模拟技术在大型铸钢件生产中的应用

大型铸钢件在实际生产中易产生缩孔缩松、应力变形等缺陷。本文采用清华大学机械工程系开发的FDM／FEM集成分析系统，对马钢双板轧机机架及5000t油压机横梁凝固过程中的温度场、应力场进行了模拟分析，并根据模拟结果对工艺进行了改进。按照制定的工艺进行实际生产，均一次浇注成功。     

ESRC guide vanes of hydraulic turbine for Three Gorges project

1. IntroductionESRC is a special working method gathering refiningand casting of molten metal together. With its specialprocess, ESRC can counteract the weakness of commonsand castings, thus get high grade castings with goodinternal quality. In this project, a lot of research has beendone about key technologies of material, process andequipment, which are involved in making guide vane ofhydraulic turbine by ESRC, and the achievements havebeen used in practice.2. Material research2.1 Trial…     

ZG0Cr13Ni4Mo不锈钢铸件微观组织试验研究

以长江三峡水轮机叶片所用材料为研究对象，设计并浇注了两种类型的大型试件。用金相显微镜及扫描电镜观察了铸态下微观组织形态，测定了奥氏体晶粒大小、奥氏体晶粒内马氏体板条束个数和马氏体板条间距。分析了ZG0Cr13NiMo不锈钢铸件凝固相变过程，阐明了该材质最终微观组织的特点。试验结果和数值模拟结果对比，可以验证数值模拟结果的可信性。     

长江三峡水轮机转轮的翻身吊装

三峡电站水轮机转轮尺寸大,重量大,翻身吊装困难。通过采用主轴翻身法吊装工艺保证了三峡转轮顺利翻身。     

铸件凝固过程数值模拟的生产应用

以燃气轮机缸体、康明斯缸体和重152 t的大型铸钢件校直机架为例,介绍“华铸CAE”铸件凝固模拟软件的实际应用效果。通过凝固模拟,对铸造工艺进行改进,使难度较高的铸件一次试浇成功。     

我国大型铸锻件应坚持国产化之路

近年来,我国大型铸锻件行业技术水平有了较高的提升,但是整体技术水平还相当于上世纪90年代的国际水平,比较落后,面对我国对大量形状复杂、技术含量高、材料性能特殊的大型铸锻件日益迫切的需求,我国大型铸锻件行业应依托装备制造业调整振兴规划,坚持国产化道路,分享我国工业发展的巨大成果。     

Modeling and simulation of 3D thermal stresses of large-sized castings in solidification processes

When heavy machines and large scaled receiver system of communication equipment are manufactured, it always needs to produce large- sized steel castings, aluminum castings and etc. Some defects of hot cracking by thermal stress often appear during solidification process as these castings are produced, which results in failure of castings.Therefore predicting the effects of technological parameters for production of castings on the thermal stress during solidification process becomes an important means. In this paper, the mathematical models have been established and numerical calculation of temperature fields by using finite difference method (FDM) and then thermal stress fields by using finite element method (FEM) during solidification process of castings have been carried out. The technological parameters of production have been optimized by the results of calculation and the defects of hot cracking have been eliminated. Modeling and simulation of 3D thermal stress during solidification processes of large-sized castings provided a scientific basis, which promoted further development of advanced manufacturing technique.     

A real-time measuring technology for studying distortion of hydraulic turbine blade castings during heat treatment process

During heat treatment process, the distortion behavior inevitably appears in hydraulic turbine blade castings. In this research, a technology was developed for real-time measurement of the distortion in hydraulic turbine blade castings at the still air cooling and forced air cooling stages during heat treatment process. The method was used to measure the distortion behavior at the cooling stages in both normalizing and tempering processes. At the normalization, the distortion at the blade corner near outlet side undergoes four stages with alternating bending along positive and negative directions. At the tempering stage, the distortion could be divided into two steps. The temperature difference between the two surfaces of blade casting was employed to analyze the distortion mechanism. The measured results could be applied to guide the production, and the machining allowance could be reduced by controlling the distortion behavior.     

热物性值对铸钢件温度场数值模拟计算精度的影响

本文研究了铸件和铸型的热物性值对铸钢件凝固过程温度场数值模拟精度的影响,指出铸型的热物性值较铸件的热物性值对模拟计算精度的影响更大。计算时,必须正确掌握不同铸造工艺条件下确切的热物性值。     

铸件充型数值模拟的研究进展

铸造过程计算机数值模拟技术是当今材料科学的重要前沿领域。本文从铸件充型数值模拟的发展过程、软件的开发状况、计算方法及验证方法等四个方面介绍了国内外铸件充型过程计算机数值模拟的概况。     

大型铝合金铸件水力模拟与数值模拟的研究

为保证大型铝合金铸件的质量,通过水力模拟和数值模拟两个途径优化铸造工艺;水力模拟依据相似理论,建立水力模型,选出最佳浇注系统,防止吸气、浇不足等缺陷;数值模拟通过计算铸件动态温度场,来预测缩孔、缩松等缺陷,据此来改变冒口、冷铁的尺寸及数量,控制铸件凝固顺序,保证铸件内部质量,最后,综合水力模拟和数值模拟结果。确定了合理的工艺方案,确保铸件一次浇注成功。     

电渣熔铸模拟三峡真机导叶组织性能研究及应用

主要介绍了电渣熔铸模拟三峡真机导叶各部位组织与性能及真机导叶的批量生产情况.模拟三峡真机导叶内部无缩孔、气孔、裂纹等铸造缺陷,残余夹杂物细小、均匀分布,有害元素S含量降低约1/3,钢液纯净,组织致密,大截面(590mm)中心部位成分偏析轻微,力学性能完全符合三峡导叶的技术条件要求.24件三峡真机导叶的力学性能与模拟真机导叶的相比,其韧性及塑性指标有不同程度的提高,表面质量也得到改善.     

三峡水轮机叶片用不锈钢的熔炼

一重公司通过对钢包精炼炉进行真空氧脱碳(VOD)改造(安装水冷氧枪和真空加料系统),成功地熔炼并浇铸出碳含量在0.03wt%以下且气体含量很低的三峡水轮机用不锈钢叶片。所制叶片不仅化学成分、冶金质量均达到了设计要求,而且比以往工艺降低生产成本约13%,技术经济效益十分可观。     

双相不锈钢复合钢板的焊接

举世瞩目的三峡工程在排砂钢管的制作安装中,选用了双相不锈钢复合钢板,这在国内水电建设中尚属首次.而双相不锈钢复合钢板的焊接在金属结构制作安装中要求高,难度大.为此进行了大量的工艺评定、焊工培训以及产品焊接等应用研究.较全面地掌握了双相不锈钢复合钢板的焊接技术,保证了三峡工程金属构件的制造安装.     

特厚大砧座铸件的铸造技术研究

结合计算机凝固模拟技术的应用,对厚大砧座铸钢件的铸造工艺及技术进行了研究,成功完成了厚度达到2 350 mm且需要进行整体超声检测的外贸特厚大铸钢件的铸造。     

大型铸钢件用醇基锆英粉涂料的研制与应用

介绍了大型铸钢件用醇基锆英粉涂料的组成、生产工艺路线及其工艺性能特征,研究了醇基铸造涂料的选材、生产工艺等对涂料性能的影响。该涂料抗粘砂能力强,悬浮性、刷涂性、流平性优异,一次刷涂所得涂层厚度高,适用于各种铸钢件尤其是大型铸钢件的生产,可有效地防止粘砂等缺陷,获得表面质量优良的铸件。     

大型风电球墨铸铁件的生产实践

以轮毂为例,介绍对大型风力发电机球墨铸铁件生产工艺进行的试验研究。通过优化铸型工艺,采用适当的浇注系统和低温石墨化退火工艺,选择合理的化学成分,控制球化处理与孕育处理,可生产出各项性能指标合格的风电铸件。     

铸钢件凝固过程计算机模拟技术应用研究

介绍清华大学开发的计算机三维数值凝固模拟软件FT—Star的功能及其在二重集团公司的工艺性试验和应用研究。解决了软件实际应用于铸钢件凝固过程中出现的一些问题,摸索出一些计算经验和规律。对不同铸钢件如何恰当地剖分网格、确定缩孔缩松判据参数、优化补贴工艺设计等都进行了深入研究,保证了计算机数值模拟结果的精确、可靠。实现了铸造缩孔缩松缺陷的预测,避免过去靠经验来进行铸造工艺设计,使工艺设计更具有科学性,大大降低了铸造生产成本。