Fractures of Structural Steels (Part 4)

Group II of fractures (in accordance with the earlier suggested classification [1]) is considered. This group is represented by fractures caused by discontinuities existing in the metal. The fractures are described and causes of their formation determined. Methods for prevention and elimination of fractures of this kind and their relationship with the mechanical properties of the steel are presented. Every kind of fracture is illustrated. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 34 – 39, June, 2005.     

Fractures of Structural Steels (Part 3)

The second part of group II of fractures (in accordance with the classification presented in the first paper [1]) is considered in detail. The deviations in the structure of these fractures from the fiber and crystalline patterns are caused by the action of high temperatures on the metal. The characteristics of fractures, the causes and conditions of their formation, and the interconnection with the mechanical properties of the metal are considered. Each kind of fracture is illustrated.     

Characteristics of Stages (Periods) of Load-Extension Curve of Structural Steels

Metal Science and Heat Treatment - Specimens of armco iron and steels 09GS and 37G2S possessing strongly different load-extension diagrams are studied. The σ = f (δ) curves are divided...     

Fracture Surfaces of Structural Steels

The kinds of fracture of standard process samples and impact specimens obtained due to single static or impact bending are classified in accordance with the conditions and causes of their formation. Group I of fractures in this classification is considered, namely, fiber and crystalline fractures of structural steels, their characteristics, conditions and causes of formation, and interrelation with mechanical properties. Every kind of fracture is illustrated.     

结构钢的加氧渗氮

对结构钢的加氧渗氮速度、硬度、硬度梯度和性能的影响及加氧渗氮机理进行了探讨。结果表明,加氧渗氮大大提高了渗氮速度,与纯氨渗氮相比可缩短渗氮时间60%以上。     

有关合金结构钢的标准

1　引言ＧＢ30 77- 1988《合金结构钢技术条件》自 1988 0 2 2 2发布 ,1989 0 3 0 1实施。 1999年国家有关部门对ＧＢ30 77-1988《合金结构钢技术条件》进行了修订 ,新标准号为ＧＢ/Ｔ30 77- 1999,标准名称为《合金结构钢》。2　新标准主要修改的内容ＧＢ/Ｔ30 77- 1999《合金结构钢》标准对下列技术内容进行了修改 :(1)标准名称改为《合金结构钢》 ;(2 )经供需双方协商 ,可提供 >2 5 0ｍｍ的棒材 ;(3)增加钢产品标记代号和牌号的统一数字代号 ;(4 )删除 30Ｍｎ2ＭｏＷ、2 0Ｍｎ2Ｂ、2 0ＳｉＭｎＶＢ、2 0Ｃｒ3ＭｏＷＶＡ、2 0ＣｒＶ等 5个…     

碳素结构钢新标准

碳素结构钢不是热处理的主要钢种,但本刊表面改性栏目中常有Q235钢渗铝或渗铬的文章出现,从标准化角度来看尚有不足,即缺少质量等级的表述.在GB/T 700-2006《碳素结构钢》发布和实施之际,撰写该文对碳素结构钢作一简介,以便更好地贯彻和执行新标准.     

升水·贴水(二)

两地之间期货的升、贴水 顾名思义,两地之间期货的升、贴水就是两地之间期货价格的基差变化情况.具体到我们铜行业,主要是指伦敦与上海之间的期货铜价格的升、贴水情况.     

Modern High-Strength Structural Steels for Aircraft Engineering

Main directions in the development of high-strength medium-alloy structural steels and production methods raising their strength characteristics without decreasing their operational capacity in aircraft structures are considered. The novel structural steels VKS-6, VKS-8, VKS-9, and VKS-12 possess high characteristics of toughness and ductility and resistance to corrosion cracking and fatigue with a strength of up to 2300 MPa.     

美国海军舰艇用钢板消耗量

美国海军舰艇用钢板从第二次世界大战后到20世纪50年代期间,根据水面战斗舰艇和潜艇发展的需要,以高强度钢HTS,屈服强度为340MPa的C—Mn钢为主。在20世纪50至70年代逐步发展了以Ni-Cr—Mo—V系为主的HY系列高强度高韧性钢,     

Combined Low-Temperature Chemicothermal Treatment of Structural Alloy Steels

It is recommended to raise the wear resistance of small arms and guns by a combined process of low-temperature chemicothermal treatment known as nicotriation. The antifriction properties of nicotriated steels are improved by holding (impregnating) them in an atmosphere of superheated vapors of ammonium molybdate. The authors study the variation of the effective friction coefficient ffr of impregnated nicotriated coatings in friction under the conditions of life-extending lubrication. The micromechanisms of seizure on rubbing microcontacts are studied with the use of the developed acoustic method for diagnostics of adhesion processes in the friction zone and the local friction coefficient.     

Structural Inheritance of Cast Steels for Road Tools

Mechanical properties and special features of structure of cast high-strength steel 23Kh3N2GFL used for the production of blades and dippers of road machines are considered. It is shown that castings from this steel have low impact toughness and ductility due to the structural inheritance that occurs in heating for quenching. It is suggested that steel 23Kh3N2GFL should be replaced by new grades of steel with a diminished nickel content, which possess high mechanical properties and are not susceptible to structural inheritance.     

结构钢组织和性能的计算机预测

介绍了结构钢组织和性能预测的数值方法，给出了预测过程所涉及的基本公式。作者利用这种方法建立了结构钢组织和性能预测的计算机软件包，给出了应用实例。     

抗地震用建筑结构钢的显微组织及成分设计

地震波谱分析表明，地震区建筑结构用钢受震时的主要失效形式是高应力低周疲劳损伤和断裂。提高建筑结构钢的抗震性，应在保证钢材具有较高强度的同时，提供其塑性和韧性。低碳微合金铁素体晶粒超细化钢、双相钢和低合金相变诱发塑性钢都具有良好的抗震性。本文对钢的抗震性、显微组织和成分设计进行了简要阐述。     

Structural Features and Application Prospects for High-Nitrogen Austenitic Steels

Metal Science and Heat Treatment - The particular features of structure formation in high-nitrogen austenitic steels characterized by intermittent decomposition of solid solution and...