标准对真空热处理温度均匀性的新要求

对真空热处理温度均匀性的新要求 New NADCAP Requirements for Temperature Uniformity for Vacuum Heat Treatment according to AMS 2750D NADCAP依据AMS2750D 标准对真空热处理温度均匀性 的新要求 Janusz Kowalewski – Vice General Manager SECO/WARWICK Tianjin Industrial Furnaces Tianjin China 亚诺 . 斯基---赛科/沃克公司天津工业炉有限公司 副总经理 注NADCAP 是―国家航空和国防承包商认证程序‖的缩写 In conjunction with constant technological development in the aerospace industry field the requirements set for equipment for heat treatment have increased particularly in the area of temperature uniformity precision the repeatability of results and the proper archivization of results. Much attention is also being given to processes for facilitating the attainment of the proper balance between advanced technologies and their economic aspects. This places new demands in the coming years on the suppliers of vacuum furnaces and it creates the need to adapt furnace design to the changing requirements and expectations of the market。 配合航空工业领域技术的不断发展对热处理设备的要求也相应提高特别在 温度均匀性精度、热处理结果的重复能力、以及适当的其结果编档保存方面。人们 更关注设备程序上要达到技术先进和其经济上合理的平衡。近几年真空炉的制造商 都将这些作为新的要求迎合对炉子的改进和市场的期望而创造出相应的提高。 The majority of world manufacturers and contractors operating in the aerospace industry are associated with the international program Nadcap which was begun in 1990 by the PRI Performance Review Institute an outgrowth of the SAE organization. This program was designated initially as NADCAP an acronym for National Aerospace and Defense Contractors Accreditation Program. Currently in order to lend the program an international character only the acronym Nadcap is used. 航空工业方面大多数的世界 制造商和承包商在国际NADCAP规划下组织一起这个组织是1990年由PRI性能审查 协会开始的是SAE美国汽车工程师学会派生形成的。它最初定名为NADCAP是国家 航空和国防承包商认证程序的缩写。现在为了借用这个程序的国际性质仅用其首字 母缩写为Nadcap. Within the Nadcap framework the primary manufacturers of aerospace equipment aim toward technological development and increase the quality of products among their contractors subcontractors by imposing strict process and procedures requirements. The Nadcap development plan establishes the total elimination of unaccredited contractors in this program over the course of the next few years. Growing number of subcontractors worldwide stimulated by new production programs e.g. the Airbus A380 the Boeing 787 Dreamliner requite adaptation of strict quality procedures. 在Nadcap的构架下主要的航空设备制造商的目的是提高技术再者就是严格程序和 步骤的要求使承包商转包商提高产品的质量。在以后的几年 1Nadcap发展计划确定 排除全部未经认可的承包商。受新生产规划例如空客 A380 波音 787 梦班机的激 励不断增加的转包商也要求其严格的质量步骤。 In the field of heat treatment the program of annual Nadcap audits is based on inspection list AC7102 prepared in compliance with the SAE AS7102 standard National Aerospace and Defense Contractors Accreditation Program -- REQUIREMENTS FOR HEAT TREATING which were developed in 1993 and were revised in 1995: 在热处理领域年度Nadcap审查以检查 AC7102目录为基础遵从SAE AS7102标准国家航空和国防承包商认证程序---热处理 要求其是1993年实施并在1995年修改的 AS7001 National Aerospace and Defense Contractors Accreditation Program NADCAP - Program Description NADCAP-程序描 述 AS7002 National Aerospace and Defense Contractors Accreditation Program NADCAP- Rules for Implementation NADCAP-执行规则 AS7003 National Aerospace and Defense Contractors Accreditation Program NADCAP- Program Operation NADCAP-程序操作 AS7101 NADCAP-Requirements for Accreditation of Materials Test Laboratories NADCAP- 对材料检测条件的要求 AS7102/1 NADCAP-Requirements for Heat Treating Accreditation Programs- Brazing Requirements NADCAP -对热处理鉴定程序要求—钎焊要求 AMS 2750D Pyrometry 测高温 AMS2801 Heat Treatment Titanium Alloy Parts 热处理钛合金部件 AMS 3025 Polyalkylene Glycol Heat Treatment Quenchant 聚二醇、乙二醇热处理淬火ant ARP1820 Chord Method of Evaluating Surface Microstructural Characteristics 评价 面显微组织特征的弦方法 ARP1962 Certification of Heat Treating Personnel. 热处理 人员资质 Aerospace standard AS7102 defines requirements for contractors working toward Nadcap accreditation in the field of Heat Treatment issued according to the following algorithm: 航空标准AS7102详细说明承包商的热处理工序要遵从Nadcap 的要求根据以下的运算法则发布 2Contractors who are seeking to acquire Nadcap accreditation develop internal operating procedures based upon the recommendations of the AS7102 standard. These recommendations cover: 希望获得Nadcap鉴定合格的承包 商在内部操作步骤上要符合AS7102标准的建议。这些建议是 ?? development of internal Quality System procedures 内部质量系统程序的发展 ?? planning and inspection of Heat Treatment processes 热处理程序的计划和检测 ?? training and evaluation of personnel 员工的培训与评估 ?? managing customer materials designated for heat treatment and safeguarding them properly 对顾客热处理材料的合理设计和维 护 ?? researching surface hardness metallographic hardness micro hardness and the like 研究表面硬度金相硬度显微硬度等等 ?? servicing inspection and maintenance of heat treatment furnaces. 热处理炉的服务检测和保养维修 3 AS 7102 标准 INTERNAL QUALITY SYSTEM PROCEDURES 内部质量系统程序 PLANNING AND INSPECTION OF HEAT TREATMENT PROCESSES 热处理程序的计划和检测 TRAINING AND EVLUATION OF PERSONNEL 员工的培训与评价 MANAGING AND SAFEGUARDING HEAT TREATMENT MATERIALS 热处理材料的管理和维 护 HARDNESS AND METALLOGRAPHIC RESEARCH 硬度和金相研究 INSPECTION AND MAINTENANCE OF HEAT TREATMENT FURNACES 热处理 炉的检查和维护 DETAILED REQUIREMENTS OF RELATED STANDARDS AMS2750D 相关标准的详细要求 AMS2750D In the field related directly to heat treatment furnaces requirements have been defined primarily related to: 直接与热处理 炉相关的方面主要基本详细要求是 ?? guaranteeing and documenting the precise heating speed the holding temperature and the cooling speed of heat-treated materials or parts 保证和归档记载准确的加热速度热处理材料或部件的保温温度和冷却速度 ?? periodic inspection of temperature distribution uniformity in the usable area of the furnace 定期检查使用期间炉子各个区域的温度分布均匀性 ?? inspection of the accuracy of the measuring system temperature sensors test tracks and reading regulating and recording equipment 4检查测量系统的精确性温度传感器、测试轨迹和读数、校 准和记录设备 ?? periodic calibration of testing equipment 周期性校准检测设备 ?? inspection of buildup pressure increase for vacuum furnaces 检查由于压力增加真空炉 的杂质 ?? inspection of purity of cooling gas for vacuum furnaces with gas cooling 对 于带有气冷的真空炉检查冷却气体的纯度 ?? planning of periodic prevention reviews and their scope and documentation. 定期的预防/评估计划及其范围和文件 In the area of requirements related to the accuracy of temperature regulation and uniformity standard AMS2750 Aerospace Material Specification is used most often. It was issued by SAE Society of Automotive Engineers in 1980. The most recent revision AMS2750D appeared in September 2005. It introduces stricter requirements for temperature measurement inspection and recording equipment in furnaces installed after September 2006. 关于温度校准精度和均匀性的要求通常在AMS2750航空材料性能标准中已经 有所说明。它是SAE汽车工程师学会在1980年公布的。在2005年9月推出了最近修订 版AMS2750D。在2006年9月后介绍了有关对炉子安装后的温度测量、检查和记录仪 的严格要求。 It is worth noting that a classification for furnaces was introduced in the AMS2750D with regard to minimum requirements for temperature uniformity in the work area: 值得说明的是在AMS2750D里介绍了对各级别炉子分类、而对工作区温 度均匀性的最小要求。 5Furnace class 炉子分类级别 Temperature uniformity ?C 温 度均匀性 1 ? 3 2 ? 6 3 ? 8 4 ? 10 5 ? 14 6 ? 28 The equipment developed to date at standard ?5oC was thus in class two. Thus furnace manufacturers are now faced with the obligation to meet the class 1 requirements in their standard products. 到目前为止分类 在级别2的炉子其温度均匀性标准在?5oC。那么炉子制作商现在面临的任务是使炉 子的温度均匀性标准符合级别1的要求。 Photo. 1 Temperature distribution study in accordance with the requirements of standard AMS2750D. Seco/Warwick 10.0VPT-4050/60HV universal vacuum furnace with usable area dimensions of 36‖Wx32‖Hx60‖L 900x800x1500mm. 照片1 符合AMS2750D标准要求温度分布的 研究。赛科/沃克10.0VPT-4050/60HV型通用真空炉其有效使用尺寸是 36‖Wx32‖Hx60‖L 900x800x1500mm. In its revised version standard AMS2750D imposes upon furnace users the duty of periodically inspecting the accuracy of the temperature measuring system. The so-called SAT System Accuracy Test tests are done with a frequency that depends upon the furnace class and the type of measuring equipment used in it quotAquot or quotEquot. In the case of the vacuum furnace type classed as 2D the SAT test should be performed weekly. End users of vacuum furnaces from the aerospace industry are expecting a new design solution in the area of measuring sensors recording and thermocouple feedthroughs in order to optimizing this procedure. 在修订版里AMS2750D标准加强对使用者在炉子运行期间检查温度系统精确度的责 任要求。所谓SAT检测系统精确度的检测其操作检测的频率主要依据炉子的级别和 测试设备的类型A 或E而定。在真空炉子类型级别分类为 62D的情况下SAT要求每 周检测一次。航空工业真空炉使用者希望设计一个新检测传感器、记录仪和热电偶 馈入装置等的方案这样是为了优化完善这个步骤。 Photo. 2 Dual quotSquot type thermocouple Controlling and Over-Temperature adapted to the requirements of SAT inspection procedure in compliance with AMS2750D. 图片2 双芯―S‖型热电偶控制和 超温适合 SAT检测的要求并符合AMS2750D标准。 Photo 2 presents one of the solutions used in Seco/Warwick furnaces. The so-called quotnonresidentquot SAT thermocouples may be inserted at any time including during the course of the production process into an impermeable thermo-well built into the regulatory-safeguarding thermocouple in the illustration. 照片2展示1个赛科/沃克炉子的解决方法。所谓的―非 固定‖SAT热电偶可以随时插入炉中。包括在生产过程中插入密闭的热-井结构中可 调整-保护式热电偶。如图所示。 The use of a tight cork safeguards the heating chamber of the furnace against oxidization in the event of a mechanical failure of the thermo-well. 使用密闭塞子装置在热-井结构发生机械故障事件时防止炉子加热室氧化。 Vacuum furnaces for materials or subassembly heat treatment utilized in the aerospace industry should also meet the following general requirements 1: 航空工业领域的真空炉对材料 或部件热处理时要符合以下常规要求1 ?? maximum vacuum empty and cold furnace after degassing in the range of 10-6 Torr 极限真空度排气后空炉和冷炉在10-6 乇的 范围 ?? working vacuum at a level of 10-4 - 10-5 Torr 工作真空10-4 - 10-5乇水平 ?? high accuracy of regulation and temperature uniformity during heating and cooling 在加 热和冷却时高精度调节和温度均匀性 7?? heating capacity of furnace sufficient for heating the charge through the range of temperatures of technological utilization with a speed of 20oC/min to 400C/min for example. 炉子对工件有充足的加热能力在技术使 用范围中实际加热速度是每分钟摄氏20-40度。 ?? cooling time of the charge from a temperature of 11000C to 540oC for example for the array of parts used in these industries at a maximum level of 6 min which is normally reached in furnaces with a cooling gas pressure of 1.5 bar abs. 例如在炉中排列的工件在1.5巴绝对压力冷却气体 下工件从温度1100度冷却到540度的冷却时间最多用6分钟。 ?? cooling of the charge with inert gas most often argon Ar with a purity of at least 99.999. 用惰性气体冷却工 件通常是纯度至少99.999的氩气 In the figure inserted below sample results of temperature uniformity researched in compliance with AMS2750D are presented during the segments of heating and holding at a given temperature. 如下图所示在给定温度菜 单下加热和保温的工件呈现的温度均匀性符合AMS2750D标准。 5506006507007508008509009501000105014:00:0414:04:0414:08:0414:12:0414:16:0414:20:0414:24:0414:28:0414:32:0414:36:0414:40:0414:44:0414:48:0414:52:0414:56:04t/c 1t/c 2t/c 3t/c 4t/c 5t/c 6t/c 7t/c 8t/c 9min. Temp 6694 Cmax. Temp 6950 CΔT256 Cmin. Temp 7472 Cmax. Temp 7733 CΔT261 Cmin. Temp 8587 Cmax. Temp 8755 C ΔT168 C6 min.min. Temp 901.9 C max. Temp 904.8 min. Temp 900.7 C max. Temp 904.8 C ΔT4.1 C 8The standard vacuum furnace for the aerospace industry yields results of approx. ?10?C in temperature uniformity during the course of heating and below ?3?C during the holding segment. The temperature stabilization time following the beginning of the holding segment is approx. 5 min until the range of ?5?C is reached and another 5 min. until total temperature stabilization at a level below ?3?C is achieved. This feature is especially important for a quality brazing processes. 航空工业 领域的标准真空炉在加热时温度均匀性大约是?10?C、而在保温时温度均匀性小于 ?3?C。温度稳定的时间从保温阶段开始计算约5分钟后达到?5?C温度均匀性范围然 后再经过一个5分钟获得整体温度均匀性好于?3?C水平。这个特性对工件钎焊质量 方面很重要。 Heat-retentive alloys of nickel and cobalt austenitic and martensite stainless steels and titanium alloys are use in the aerospace industry. 镍/钴硬磁性合金、 奥氏体和马氏体不锈钢、和钛合金都用在航空工业上。 For brazing processes two furnace designs are currently offered: furnaces with metal shield insulation or furnaces with insulation made up of graphite composites. 在钎焊处理中通常提供设计两种炉子 带有金属隔热屏的真空炉、或是带有石墨隔热屏的真空炉。 Photo. 3 Seco/Warwick type 6.OVP-4050/48MHV vacuum furnace with 6 bar cooling capability and all metal insulation and moly heating elements. 照片3 赛科/沃克6.OVP-4050/48MHV型真空 炉、6巴冷却压力、全金属隔热屏和钼镧加热元件 9A typical feature of vacuum furnaces with metal insulation is somewhat higher heat losses at a high temperature for example1200oC heat losses are approx. 10-11 kW/m2 in comparison to graphite chambers. After a certain period of utilization depending upon the quotpurityquot of heat treat processes these losses increase to a level of up to 15-16 kW/m2. Such changes in heat losses over time means that it is significantly more difficult to maintain the temperature uniformity and increases energy consumption during heat treatment cycles. The design of heating zones heating elements and for the manner of placement of heating elements are of key significance to the technological properties of these furnaces. 与石 墨隔热屏炉室相比较、全金属隔热屏真空炉的一个典型特征是在高温下损失的热量 会多一些例如1200oC热量损失是大约10-11 kW/m2 。炉子经过一段时间的使用后决 定于热处理过程的―净化‖程度这个损失增加到15-16 kW/m2 。随炉子使用时间延长 而热损失的这些变化意味着在热处理周期保持炉温均匀性是相对很困难的、并增加 了能量消耗。因此炉室加热区的设计、加热元件在加热室中的布置是决定这些炉子 技术性能的关键重点。 The cost of a heating chamber with all metal insulation is higher than that of a heating chamber with graphite insulation. Moreover to ensure the certainty of obtaining a temperature distribution over a long period of utilization it is sometimes necessary to use zone regulation adding heating elements to the door and the back wall will increase the investment and utilization cost. With the proper quality of materials for the insulation wall and properly selected vacuum pumps graphite insulation likewise ensures the level of the working vacuum at the level of 10-4 ? 10-5 Torr and the maximum vacuum of even at 10-6 Torr range. 全金属隔热屏加热室的成本要比石墨隔 热屏加热室的成本高。而且为了确保长期使用后获得一定的温度均匀性分布有时必 须对加热区进行校准、另外在炉门和炉后墙增加加热元件这样会增加炉子的投.