一项评估液压油能否混用的新规程——ASTM D7752-2011简介与评述

ASTM D7752-2011是一项用于评估液压油能否混用的标准规程,由ASTM D02石油产品和润滑剂技术委员会D02.N0.09相容性分技术委员会制定。该规程规定通过ISO 13357-1过滤性试验来评估液压油混合后的相容性,这是迄今为止液压油混用研究领域里的一项最全面、最完善的标准规程。依据ASTM D7752-2011原文对该标准规程进行了介绍,对涉及到的ISO 13357-1过滤性试验也给出了详细的操作说明,此外开展了该规程与国内同类方法 GJB 562-1998和Q/SHGQ 01.475-2002的对比分析。建议国内有关单位在进行液压油的混用操作前参考使用该标准规程。     

建筑幕墙气密性能检测方法国标美标异同分析

以一个检测人员的视角,从试件要求、测试程序、结果处理三个方面对GBT15227-2007和ASTME283-04规定的建筑幕墙气密性能测试方法进行了异同分析,供同行参考。     

煤矿井下用难燃液压传动介质综述

为推动煤矿用环境友好难燃液产品认证与应用,结合我国煤矿用难燃液的应用与研发现状,对比分析目前国际上有影响力的环境友好难燃液评价标准,提出牢固树立环境友好难燃液全生命周期管理理念、实现源头危害预防,系统研究国际标准、持续完善评价项目和方法体系,准确把握品质属性与环境属性关系、不断提升环保技术要求等建议。

     

管线钢带状组织有关评定标准的分析探讨

介绍了目前管线钢中带状组织常用的评定标准,即ASTM E 1268—2007《显微组织的取向或带状物等级的评定方法》和GB/T 13299—1991《钢的显微组织评定方法》。从制备试样方法、试样观察面位置和数量、试验结果取值范围和带状物评定参数等方面说明了ASTM E 1268—2007和GB/T 13299—1991的适用性。结果表明,这两个标准目前已不适用于管线钢带状组织的评级。最后给出了较为适合的评级方法,即“针状铁素体型管线钢带状组织评定方法”。     

The influence of thermomechanical treatment on the microstructure and mechanical properties of aisi 4130 steel

Ultra high strength AISI 4130 Steel samples were submitted to various rolling schedules in order to find the rolling conditions leading to the optimum combination of strength and toughness. Reheating temperatures between 900 to 1230°C and reductions between 15 to 90% were employed. Rolling temperatures above Ar3 and also between 620 and 700°C were used and in some experiments annealing was applied to the samples. The influence of the above parameters on the microstructure and mechanical properties of the samples was studied by measuring the variation of their hardness, tensile and impact properties as well as using optical and scanning electron microscopy. The results show that by a judicious control of reheat temperature, percent deformation, interpass time, finish rolling and annealing temperatures it is possible to obtain fine ferrite and nodular colonies of pearlite with small interlammelar spacing. The results are discussed in the frame work of classical nucleation theory and the possible mechanisms which may be responsible for the observed behavior are proposed.     

Use of TBM muck as construction material

Tunnel boring machines (TBMís) are widely used in tunnel construction in rock. The rock chips (muck) produced are rarely used for construction applications, however, because the suitability of the material is not well understood. Yet the cuttings appear to be of approximately the correct average size for some applications. If they are suitable in other respects, cost savings can be realized in tunnel construction, where aggregate is a common requirement. A review of standard construction aggregate specifications indicates that hardrock TBM much would be suitable for several construction applications with a minimum of processing: road pavement and structural concrete. Processing options also are discussed for cases where the raw TBM muck is nearly, but not quite, suitable. A 0.65 metric ton (1420 lb) cutting sample generated by a laboratory tunnel boring machine operating in a welded tuff is analyzed for suitability for different construction applications. In addition, numerous tunneling projects that use or have studied TBM waste for construction purposes are described.     

ASTM金属材料拉伸试样介绍

介绍了ASTME8和E8M标准中的金属材料拉伸试样的类型和尺寸，并与我国相应的标准试样进行了比较。     

塑料性能测试中一些问题的探讨

以熔体流动速率为例，阐述塑料性能测试条件应尽量接近生产和使用奈件。对一些易被曲解和误用的性能进行了讨论。还简要地探讨了CAD和CAE所需的性能数据、性能测试的价格，并对ISO与ASlM测试方法进行了比较。     

某台国产压水堆压力容器锻件材料断裂韧性韧脆转变的参考温度

摘要：采用紧凑拉伸c（T）试样测试了某台国产反应堆压力容器用508-Ⅲ锻件的主曲线参考温度死。为了方便今后在热室中进行辐照材料的断裂韧性试验,专门修改了c（T）试样的前端面设计。有限元分析和采用修改、未经修改的C（T）试样的试验结果均表明,对试样的修改不会影响断裂韧性试验。发现C（T）试样测得的瓦值与前期采用三点弯曲SE（B）试样确定的％值仅相差约1℃。为此详细探讨了ASTME1921标准第1．3和5．7条款有关试样形式对％的影响,试验结果印证了这些条款的阐述,所测得的r,n试验值接近材料的％平均值。     

ASTM 4130钢的局部脆化研究

利用焊接热模拟试验以及金相和透射电镜技术研究了中碳调质钢ASTM 4130钢的组织转变与冲击性能的关系。结果表明,一次热循环的粗晶区和二次热循环的临界粗晶区是调质态ASTM 4130钢焊接热影响区的2个局部脆化区,相对母材韧性损失分别达94.5%和96.6%。粗晶区脆化的主要原因是大量上贝氏体和未回火马氏体的生成以及晶粒粗大;沿晶分布的"项链"状M-A组元和块状铁素体的存在是临界粗晶区脆化的主要组织因素。