氢化钛—铝混合粉机械合金化研究

用ＳＥＭ，ＸＲＤ，ＤＴＡ方法研究了氢化钛与铝的混合粉在搅拌球磨过程中粉末的形貌和物相变化，实验结果表明，球磨４８ｈ后出现非晶化，氢化钛可以降低球磨初始阶段的过分冷焊现象，在搅拌球磨过程中氢化钛发生脱氢反应，脱氢后的Ｔｉ易与球磨气氛中残余氮气形成氮化物。     

低钛含量钢电渣重熔保钛工艺研究

讨论低钛含量钢30CrMnMoTiA电渣重熔保钛工艺。通过对TiO2渣料的加入方式和配比的改进进行保Ti，并对其他化学成分进行分析比较，认为在重熔过程中连续均匀加入TiO2不仅能保钛，亦能使电渣锭在轴向高度上的钛含量更趋均匀。     

模具材料DT—40钢结硬质合金的显微组织特色

对于ＤＴ－４０钢结硬质合金进行了细致的微观分析，其原始组织中出现的亮区与暗区分别由大块硬质相与细小碳化的密集分布相间而成，经在９６０－１１００℃宽范围内加热淬火均可获得细的马氏体组织，此材料碳化物数量众多并具有大、中、小三种不同尺寸的分布。其微观组成单元上的显微硬度测量及分析结果与宏观洛氏硬度值之间有很好的对应。     

RE—B对Si—Mn铸钢强韧性的影响

稀土，硼，稀土－硼加入Ｓｉ－Ｍｎ铸钢能够细化铸态组织，制或消除针状网状铁素体，并增加铁素体数量，经高温淬火代温回火，能改善马氏体的亚结构，增加回火碳化物数量，并在马氏体板条间出现残余奥氏体薄膜，从而改善了Ｓｉ－Ｍｎ铸钢的力学性能，尤其是韧性。     

2.8%Ni—Mo—V钢组织遗传与晶粒细化

用实验方法研究了２．８％Ｎｉ－Ｍｏ－Ｖ钢组织遗传粒细化工工艺，实验结果表明６５０℃回火和７７０℃退火可使该钢的粗大奥氏体晶粒细化，淬火回火后获得较高的冲击值。     

含镉铸造铝铜合金的微观组织

当ＺＬ２０１Ａ中加入微量元素镉时，合金微观组织随着镉量的增加，在１７５℃时效时，金相组织由α加θ”逐渐变成α加θ”加θ’相。当含镉量为０．３％左右时，合金抗拉强度达到峰值，微观组织为α＋θ”＋θ’。研究表明镉的含量不同、θ”、θ’相的大小、数量及配比均不相同。本文还分析讨论了过渡相析出的惯析面。     

微量钛对低碳硼钢冲击韧性的影响

研究了微量钛对低碳硼钢冲击韧性的影响．结果表明：在－６０℃～＋２０℃范围内，加入微量钛的低碳硼钢的冲击韧性普遍较好，随着温度升高，冲击韧性值增大，但其冲击韧性值变化幅度不大．在－６０℃～＋２０℃范围内，必须的钛含量超出时，这些过剩的钛对低碳硼钢的冲击韧性没有明显影响．     

包钢低碳铝镇静钢的冶炼与浇铸

介绍了包钢炼钢厂小方坯连铸机开发生产新钢种以及转炉采用新型复合脱氧剂生产低碳铝镇静钢的工艺路线,采用新型工艺路线及脱氧剂脱氧合金化后,Al收得率平均提高1倍以上,钢中氧的质量分数控制在10×10-6～50×10-6,低碳铝镇静钢的炼成率达99%以上,铸坯质量合格.     

Microstructural evolution and tensile properties of low-carbon steel with martensitic microstructure during warm deforming and annealing

For preparing large-scale nano-grained and ultrafine-grained steel sheets by warm rolling and annealing,the effects of de- forming temperature on both the flow stress and the microstructure evolution of 09MnNiD steel with lath martensitic microstructure were studied by warm-compression test and transmission electron microscopy(TEM)observation.Thereafter,the steel with the lath martensitic structure was multi-pass warm-rolled and then annealed.TEM results indicate that nano-grained and ultrafine-grained steel sheets are formed by warm rolling at 400℃and annealing at 400-600℃.In comparison with the as-warm-rolled specimen,the tensile strength at room temperature changes a little when the rolled samples are annealed below 450℃,and the tensile strength is greatly lowered as the annealing temperature increases to above 550℃.     

钛在钢水中的行为

介绍了钛在钢水中行为的研究结果,包括钛在钢中的脱氧能力、脱硫能力以及对非金属夹杂物的影响,这些研究结果对于冶炼含钛钢,控制钢中夹杂物的形态,提高连铸坯质量,制定钢的轧制和热处理工艺都具有重要意义。     

Metal magnetic memory signals from surface of low-carbon steel and low-carbon alloyed steel

In order to investigate the regularity of metal magnetic signals of ferromagnetic materials under the effect of applied load, the static tensile test of Q235 steel and 18CrNiWA steel plate specimens were conducted and metal magnetic memory signals of specimens were measured during the test process. The influencing factors of metal magnetic memory signals and the relationship between axial applied load and signals were analyzed. The fracture and microstructure of the specimens were observed. The results show that the magnetic signals corresponding to the measured points change linearly approximately with increasing axial load. The microstructure of Q235 steel is ferrite and perlite, whereas that of 18CrNiWA steel is bainite and low-carbon martensite. The fracture of these two kinds of specimens is ductile rupture; carbon content of specimen materials and dislocation glide give much contribution to the characteristics of magnetic curves.     

Ultra-high cycle fatigue behavior of high strength steel with carbide-free bainite/martensite complex microstructure

The ultra-high cycle fatigue behavior of a novel high strength steel with carbide-free bainite/martensite (CFB/M) complex microstructure was studied. The ultra-high cycle fatigue properties were measured by ultrasonic fatigue testing equipment at a fre-quency of 20 kHz. It is found that there is no horizontal part in the S-N curve and fatigue fracture occurs when the life of specimens exceeds 107 cycles. In addition, the origination of fatigue cracks tends to transfer from the surface to interior of specimens as the fa-tigue cycle exceeds 107 , and the fatigue crack originations of many specimens are not induced by inclusions, but by some kind of "soft structure". It is shown that the studied high strength steel performs good ultra-high cycle fatigue properties. The ultra-high fa-tigue mechanism was discussed and it is suggested that specific CFB/M complex microstrueture of the studied steel contributes to itssuperior properties.     

高硼铸钢衬板的组织和性能

针对高锰钢衬板初始硬度低,在中、小型球磨机的工况条件下不能充分发挥加工硬化效应的情况,研制了高硼铸钢衬板。该衬板是在低碳钢中加入硼合金元素的同时添加少量其他合金元素,可以获得一定数量的高硬度Fe2B化合物,基体是强韧性好的板条马氏体,综合力学性能与耐磨性良好,硬度大于58 HRC,冲击韧性大于12 J/cm2,适用于小能量多冲击的凿削磨损型工况条件。用于替代高锰钢制造球磨机衬板,寿命比高锰钢提高2倍以上,且价格相当,经济效益好。     

Effect of fast cooling rate on the microstructure and mechanical properties of low-carbon high-strength steel annealed in the intercritical region

The effect of fast cooling rate on the microstructure and mechanical properties of low-carbon high-strength steel annealed in the intercritical region was investigated using a Gleeble 1500 thermomechanical simulator and a continuous annealing thermomechanical simulator. The results showed that the microstructure consisted of ferrite and bainite as the main phases with a small amount of retained austenite and martensite islands at cooling rate of 5 and 50 ℃/s, respectively. Fast cooling after continuous annealing affected all constituents of the microstructure. The mechanical properties were improved considerably. Ultimate tensile strength(UTS) increased and total elongation(TEL) decreased with increasing cooling rate in all specimens. The specimen 1 at a cooling rate of 5 ℃/s exhibited the maximum TEL and UTS×TEL(20% and 27 200 MPa%, respectively) because of the competition between weakening by presence of the retained austenite plus the carbon indigence by carbide precipitation, and strengthening by martensitic islands and precipitation. The maximum UTS and YS(1 450 and 951 MPa, respectively) were obtained for specimen 2 at a cooling rate of 50 ℃/s. This is attributed to the effect of dispersion strengthening of fi ner martensite islands and the effect of precipitation strengthening of carbide precipitates.     

钛微合金化高强度耐候钢成分设计及熔炼

在普通耐候钢Q450NQR1成分的基础上,通过理论计算,设计出一种钛含量为0.04%～0.10%、屈服强度为520～750 MPa的高强度耐候钢。按照成分设计要求,采用高频真空感应炉在1 873 K条件下熔炼钢样,并对不同钛加入量的钢样进行成分和组织结构分析。结果表明,熔炼的钢样中氧含量为（17～26）×10-6,氮含量为（12～66）×10-6,钛含量为0.006 1%～0.059 0%;钢样组织主要由铁素体和珠光体构成,随着钢中钛含量的增加,晶粒明显细化,钢组织渐趋均匀。SEM分析表明,钢中长方体的TiN夹杂,是以球形的Al2O3、MgO和钛氧化物夹杂为核心生长的,必要时在微合金化处理之前将钢中的氧含量降低到一定程度。