航天用新型无钴高强高韧钢G50研制

G50是我国自行设计的专利产品。本钢特点不含钴，属于低合金超高强度钢，但又具有含钴超高强度钢9Ni-5Co的性能。本文介绍该钢的化学成分及高纯熔炼冶炼技术，钢的热处理，力学性能及其钢的显微组织特性。     

高强高韧钢中奥氏体相电子结构的计算及其合金化行为

在紧束缚框架下用Ｒｅｃｕｒｓｉｏｎ方法计算了高强高韧钢中奥氏体相的电子结构,计算了替位和间隙固溶元素的局域态密度（ＬＤＯＳ）。通过总态」密度（ＴＤＯＳ）的积计算了体系的结果能及原子间的键级积分,讨论了闰和间隙固溶元素对合金钢奥氏体相物理性能的影响。     

超纯航天用高强度韧钢G99的研制

根据“８５”国家科技攻关项目的要求，由冶金部钢铁研究总院，川投长城特殊钢公司，航天部七０三所，东北大学四家共同承担了Ｇ９９钢的研制，而工业试制完全川投长城特殊钢公司进行。公司通过对Ｇ９９钢冶炼工艺，热加工工艺，热处理工艺及要点的研究，准确确定了Ｇ９９高强度韧钢的各项工艺制度与流程，并成功试制出了“具有高位错密度的亚组织结构，有呈黑白球型粒子存在的，以γ－Ｍｏ型及Ｔｉ－Ｎｂ型的碳化物弥散基体中的达到     

航天用新型无钴高强高韧钢G50研制

本文介绍了G50钢的研制。该钢是我国自行设计的专利产品。本钢特点不含钴属于低合金超高强度钢，但又具有含钴超高强度钢9Ni--5Co的性能。本文介绍钢的化学成分及高纯熔炼冶炼技术，钢的热处理，力学性能及其钢的显微组织特性。     

新型G99高强高韧钢中渗碳体的电子结构

应用Ｒｅｃｕｒｓｉｏｎ方针计算了新型Ｇ９９高强高专心钢中渗碳体、合金渗碳体的电子结构。给出了不同合金元素的电子态密度、原子价、轨道电子数和体系的费米能、结构能。讨论了渗碳体、合金渗碳体的价键性质及其对Ｇ９９钢性能的影响。     

高强高韧铝合金研究现状及展望

简要介绍了高强高韧铝合金的发展，对其组织性能进行了全面评述，着重讨论了断裂韧性和应力腐蚀的影响，并指出今后研究工作中所需解决的问题。     

高强高导电铜合金的研究及进展

高强高导铜合金在现代电子技术和电工等领域具有广阔的应用前景,因而成为铜合金材料的研究热点之一,综述了获得高强高导电铜合金的方法,介绍了发展该类使铁最新技术及其研究现状。     

新型高强高导接触导线用Cu-Cr-Zr系合金研究进展

总结了国内外电气化高速铁路接触网用接触导线的研究和使用现状,讨论了高强高导Cu-Cr-Zr系合金应用于新一代国产化接触线的必要性和可行性.分析了Cu-Cr系合金中所添加的Zr、Mg、Sn、Ti、Si及RE等不同元素对合金性能的影响,概述了当前对于Cu-Cr-Zr系合金导电率、强度、耐磨性和抗软化性等合金性能的研究现状,总结了高强高导Cu-Cr-Zr系合金在制备工艺方面的研究情况,提出几个亟待解决的问题及对进一步的研究做出展望.     

喷射成形制备Al-Zn-Mg-Cu系高强高韧铝合金的研究

采用喷射成形技术制备了Al Zn Mg Cu系高强高韧铝合金 ,对喷射成形工艺参数进行了优化 ,对沉积坯件的热挤压工艺、热处理工艺进行了探索 ,对材料的组织进行了分析并对不同状态的材料性能进行了比较。结果表明 :当喷射成形工艺参数合理时 ,沉积坯件具有良好的成形性与致密度 ,在随后的热挤压过程中 ,通过较低的挤压比即可使材料达到全致密 ;沉积坯件热挤压温度的降低有利于使材料获得更高的力学性能 ;同时 ,通过对合金热处理的优化 ,可以获得加工和使用性能更加优良的Al Zn Mg Cu系高强高韧铝合金材料     

车体外面板用高功能高强钢板

JFE开发了两种生产汽车车体外板面板用的高功能高强钢板。一种是SFG钢板,主要用于生产要求深冲性的侧面板部件,SFG钢通过精粒细化增大了强度,并且低屈服强度（低YS）,高n值（高兰克福特值）决定的高成形性使其成为精粒细化型高强钢板。另一种是“万能高强钢”,这种钢主要用于车门、车蓬等处,其优点在于拉伸性能好、表面形状质量高（耐表面变形性）,冲压成形后的烤漆可以加强钢的硬度,在尽可能保证耐电镀性基础上减少了厚度,又可称为低YS（低屈服强度）型440MPa级BH（烘烤硬化）钢。     

Optimization Evaluation Test of Strength and Toughness Parameters for Hot-Stamped High Strength Steels

Use of hot-stamped high strength steels (HSHSS) not only reduces the vehicle weight, but also improves the crash safety, therefore more and more mentioned steels are used to produce automobile parts. However, there are several problems especially the low ductility and toughness, which have restricted the application of HSHSS in automobile body. Suitable process parameters are very crucial to improve strength and toughness. In order to study the effect of austenization temperature, soaking time and start deformation temperature on strength and toughness of boron steel 22MnB5, an L9 (3⁴) orthogonal experiment which was analyzed by means of comprehensive evaluation was carried out based on Kahn tear method to obtain the value of fracture toughness. The results indicate that the excellent formability, high strength and toughness of boron steel 22MnB5 with 1.6 mm in thickness are obtained when the austenization temperature is in the range of 920 — 950 °C, the soaking time is 1 min and the start deformation temperature is in the range of 650 — 700 °C. The optimal parameters were used for typical hot stamping structural parts tests. Properties of samples such as tear strength, unit initiation energy and ratio of strength to toughness (RST) were improved by 10.91%, 20.32% and 22.17%, respectively. Toughness was increased substantially on the basis of a small decrease of strength.     

Shear Fracture of Advanced High Strength Steels

Failure experiments were carried out through a stretch-bending test system for advanced high strength steels, i.e. dual-phase （DP） steels and martensitic steels （MS）. The die radius in this system was designed from 1 to 15 mm to investigate the failure mode under different geometries. Two failure modes were observed during the ex- periments. As a result, critical relative radii （the ratio of inner bending radius R to sheet thickness t） for DP590 and DP780 steels were obtained. The stretch-bending tests of DP980 display some trends unlike DP590 and DP780 steels, and curve of DP980 in different thicknesses does not coincide well. High blank holder force exhibits more possibility of shear fracture tendency than low blank holder force. The unique character of high strength martensitic steel （1500MS） is that no shear fracture is found especially over small bending radius （R =2 mm） under the same experi- mental conditions. Microstructure analysis indicates that there are obviously elongated grains on shear fracture sur- face. It shows smaller diameter and shallower depth of the dimples than the necking failure.     

采用细小贝氏体改进大线能量高强度钢板的热影响区(HAZ)韧性

随着建筑物向大型化、厚度化和高强度化的方向发展，研究开发出了590MPa和780MPa级超大线能量焊接用钢板。自日本阪神大地震灾害以来，在提高建筑物安全性的背景条件下，对HAZ韧性的要求更加严格。即使是进行大线能量焊接时，也要求钢板具有良好的HAZ韧性。对大     

Effect of Sulfur Contents on Fracture Toughness of Wheel Steels for High Speed Train

The effect of different contents of S on fracture toughness of railway wheel steels for high speed train has been researched.The results show that there are kinds of non-metallic inclusion when O content retaining at about 10×10-6,such as Al 2 O 3 inclusions and Al 2 O 3 +MnS complex inclusions and single MnS inclusions.This is connected with S content level in steel.Fracture toughness of railway steel increase obviously because of Al 2 O 3 covered by MnS around when S content is increase to about 70×10-6.It shows that,after Al 2 O 3 covering by MnS around,stresses around complex inclusion decrease rapidly till disappear when analyzed by tessellated stresses theory.That is the reason of fracture toughness rise.     

稀土元素在高强韧钢中的作用及应用前景

深入分析了稀土在钢中的作用机理,阐明了稀土是钢的一种有效的深度净化和变质剂,固溶稀土的存在强烈影响微结构,可控制局域弱化,降低微结构的能态,有效抑制钢中有害元素和脆性相偏聚所造成的脆性断裂,稀土可望成为发展21世纪高强韧钢,提高高强钢韧性的重要元素。     

Effect of Boron on CGHAZ Microstructure and Toughness of High Strength Low Alloy Steels

Effect of boron on the microstructure and impact toughness in the coarse-grained heat-affected zone(CGHAZ)of two high strength low alloy steels,boron-free and boron-containing,was investigated by means of weld thermal simulation test.The result shows that,for the boron-free steel,a microstructure consisting of grain boundary ferrite degenerates pearlite and granular bainite for longer t8/5(the cooling time from 800 to 500 ℃),while lath bainite for shorter t8/5.For the boron-containing steel,granular bainite is dominant for a wide range of t8/5.Continuous cooling transformation(CCT)study on the CGHAZ indicates that the transformation start temperature decreases by about 50-100℃under different t8/5,for the boron-containing steel compared with the boron-free steel.The presence of boron suppresses the nucleation of ferrite at prior austenite grain boundaries and hence enlarges the range of t8/5for granular bainite transformation.However,the addition of boron deteriorates the impact toughness of CGHAZ,which may be due to a markedly increased fraction of martensite-austenite(M-A)constituents and decreased fraction of high angle grain boundaries.     

β钛合金的强韧化机制分析

β钛合金的合金成分、热处理工艺和显微组织决定了合金的强韧性.β钛合金的β稳定元素和中型元素Zr可以提高合金的强度,降低断裂韧性.细小的β晶粒不能有效提高时效态β钛合金的强度,可以降低Ti-15-3合金的断裂韧性,对β-C和Ti-1023合金的断裂韧性无明显影响.时效态β钛合金的强度主要取决于时效析出的次生α相的含量和尺寸,在含有同样初生α相的情况下,细小的次生α相可以显著提高合金的强度.初生α相的粗化以及初生相从球状转变为片状会导致β钛合金塑性降低,断裂韧性提高.β钛合金的双态组织具有良好的强度、塑性和韧性的匹配.     

The Tensile Response and Fracture Behavior of Four High Strength Specialty Steels

In this technical paper the role of alloy chemistry and secondary processing on tensile response and final fracture behavior of four high strength steels is presented and discussed. The conjoint influence of composition, secondary processing and intrinsic microstructural features in governing stress versus strain response and tensile properties is highlighted. The macroscopic mode and intrinsic microscopic features that result from final fracture of the four high strength steels is discussed. The intrinsic microscopic mechanisms governing tensile deformation and final fracture behavior of the high strength steels are outlined in light of the specific role played by composition, intrinsic microstructural effects and nature of loading.     

Crack Arrest Toughness of Two High Strength Steels (AISI 4140 and AISI 4340)

The crack initiation toughness (K _c ) and crack arrest toughness (K _a ) of AISI 4140 and AISI 4340 steel were measured over a range of yield strengths from 965 to 1240 MPa, and a range of test temperatures from -53 to +74°C. Emphasis was placed onK _a testing since these values are thought to represent the minimum toughness of the steel as a function of loading rate. At the same yield strengths and test temperatures,K _a for the AISI 4340 was about twice as high as it was for the AISI 4140. In addition, theK _a values showed a more pronounced transition temperature than theK _c values, when the data were plotted as a function of test temperature. The transition appeared to be associated with a change in fracture mechanism from cleavage to dimpled rupture as the test temperature was increased. The occurrence of a “pop-in” behavior at supertransition temperatures has not been found in lower strength steels, and its evaluation in these high strength steels was possible only because they are not especially tough at their supertransition temperatures. There is an upper toughness limit at which pop-in will not occur, and this was found for the AISI 4340 steel when it was tempered to its lowest yield strength (965 MPa). All the crack arrest data were identified as plane strain values, while only about one-half of the initiation values could be classified this way.     

影响高速钢韧性的因素

 分析了化学成分、冶炼方法、钢中碳化物和热处理工艺等因素对高速钢韧性的影响。结果表明：纯净度高、杂质元素含量低和夹杂物少的钢韧性较高;同一钢种随碳含量升高其韧性降低;在同一类型钢种中,通常W Mo系钢的韧性优于W系钢;碳化物分布均匀、颗粒尺寸细小的钢韧性高,而碳化物分布不均匀、粗大角状碳化物多的钢韧性差;粉末高速钢的韧性显著优于常规方法生产的高速钢。热处理是影响高速钢韧性的另一个重要因素：随淬火温度升高,钢的韧性下降;回火温度较低和回火程度不充分时,也会显著降低钢的韧性。