新型微合金非调质钢的研究

研制了一种新型微合金非调质钢。通过合理设计合金成分,改善熔炼脱氧过程,控制钢中氧化物的组成、分布、形状和尺寸,在研制钢中形成微细的氧化物夹杂作为晶内铁素体最有利的析出位置。通过晶内铁素体的析出细化了晶粒,提高了钢的强度与韧性。将研制的新型微合金非调质钢用于拖拉机的牵引插销是可行且有效的。     

V的碳氮化合物析出对36Mn2V非调质钢组织性能的影响

在φ340机组上进行非调质36Mn2V和37Mn5油井管钢工艺试验,对比分析二者组织性能．研究36Mn2V钢中微合金元素V的碳氯化物析出对其组织性能的影响。结果表明。36Mn2V、37Mn5钢可分别用于高钢级N80-1和低钢级J55、K55油井管的生产,36Mn2V非调质钢在高温形变诱导下析出V（C、N）,促进了晶内细小铁素体和珠光体的析出,反之细晶铁素体析出促进了V（C、N）沿y／a界面弥散析出,故而显著改善了36Mn2V非调质钢组织性能。     

Nb含量对低碳微合金钢热处理组织与性能的影响

设计了3种含铌量不同的微合金试验钢,采用热处理模拟方法研究了900 ℃奥氏体化550 ℃等温处理后试验钢的组织、性能及第二相粒子的析出行为.结果表明,低铌钢热处理后组织为多边形铁素体加少量板条贝氏体铁素体加极少量珠光体,随着铌含量增加,试验钢组织中板条贝氏体铁素体含量明显增加,且组织细化;同时随着铌含量的增加强度提高,中高铌试验钢的屈服强度可达400 MPa,且屈强比较小(＜0.8).3种试验钢中均有铌的碳氮化物粒子析出,但析出量较少.     

600MPa级钛微合金化高强钢的组织与性能研究

采用光学显微镜、透射电镜以及能谱分析等对转炉CSP流程600 MPa级钛微合金化高强钢的组织及性能进行研究。结果表明,试验钢具有良好的综合力学性能,其典型组织为多边形铁素体加粒状贝氏体;位错和位错胞的强化作用成为钛微合金钢的主要强化机制之一;钢中M/A岛在增加试验钢强度的同时并未明显降低其韧性和塑性;试验钢中存在TiN、TiC和TiS等析出物,为钢的细晶强化和析出强化提供了保证;试验钢中存在大量纳米级铁碳析出物,其沉淀强化作用不容忽视。     

中碳空冷贝氏体钢在石油钻铤上的应用

本文对经不同冷速处理的30Mn_2CrSiMo钢进行了组织性能分析。结果表明:30Mn_2CrSiMo钢中的合金元素,能使铁素体、珠光体转变C曲线明显右移,可在模拟钻铤空冷的冷却速度范围内得到较多的粒状贝氏体组织;在试验规定的冷速范围内,钢的力学性能均满足技术要求。通过与42CrMo钢进行比较,肯定了用低、中碳贝氏体钢代替中碳调质钢制造石油钻铤是可行的。     

新型高强韧性奥—贝组织低合金钢的研究

作者应用新的合金设计思想,研制了一类新型高碳低合金超高强度钢。经适当热处理,获得贝氏体铁素体板条与奥氏体薄膜交替排列的奥氏体-贝氏体双相组织。文中研究了钢的组织、力学性能及其与转变温度的关系。     

钒,钛,稀土元素在正火钢中的存在

以添加V、V—Ti、V—RE等元素的中、低碳非调质钢为例,应用物理化学相分析及电子显微分析技术,研究了正火状态下合金元素的存在状态。表明950C正火后,钒、钛减少了碳化物总量,增加了铁素体的相对量。锰主要存在于铁素体中,仅少量溶入渗碳体和碳化钒中。钛主要以TiC、TiN形式存在。钒以VC形式存在,少量溶入渗碳体。V、Ti总有少部分滞留于铁素体中。稀土元素可固溶入钢中,增加过冷奥氏体的稳定性,影响分解产物的形态和性能。     

Mg-Ti复合脱氧对低碳微合金钢组织性能的影响

通过焊接热模拟和冲击韧性试验,研究了Mg-Ti脱氧和Al脱氧在大线能量焊接热循环条件下对低碳微合金钢粗晶区组织性能的影响。结果表明,Mg-Ti脱氧钢粗晶区的组织主要是针状铁素体（AF）和少量的多边形铁素体,Al脱氧钢粗晶区的组织主要是低碳贝氏体＋大量的块状铁素体。对Mg-Ti脱氧钢和Al脱氧钢在不同焊接热循环下的冲击韧性进行研究,结果表明随着焊接热输入量的增大,两种脱氧钢的冲击韧性都有所下降,但是从总体上来说Mg-Ti脱氧钢粗晶区的冲击韧性远远高出Al脱氧钢粗晶区的冲击韧性。     

合金元素Mo对冷轧双相钢组织的影响

分析Mo微合金冷轧双相钢和普通C-Mn冷轧双相钢在不同双相热处理工艺下微观结构,讨论Mo对冷轧双相钢组织变化规律的影响。实验结果表明：当两种双相钢以1700℃／s冷却时,均获得了铁素体、马氏体双相组织,马氏体均匀分布在铁素体基体上,随着加热温度的升高,普通C-Mn双相钢得到的马氏体体积分数多。当以5．4℃／s冷却时,Mo微合金双相钢得到的马氏体体积分数多;当加热到820℃保温结束后以5．4℃／s的速率冷却时,普通C-Mn钢的组织组成相为铁素体、珠光体、马氏体;Mo微合金钢的组织组成相为铁素体、贝氏体、马氏体;Mo对铁素体晶粒的细化作用不明显。     

Ce—Ca、Ce—Mg微合金化钢大线能量焊接热影响粗晶区组织与力学性能研究

研究Ce-Ca、Ce-Mg微合金化低合金钢大线能量焊接热影响粗晶区（CGHAZ）的力学性能、组织结构及夹杂物成分与形态。结果表明,Ce-Ca微合金化钢CGHAZ的力学性能优于Ce-Mg微合金化钢CGHAZ的力学性能;Ce-Ca微合金化钢CGHAZ中Ce、Ca的氧硫复合化合物夹杂物主要呈球状,Ce—Mg微合金化钢CGHAZ中Ce、Mg的氧硫复合化合物夹杂物主要呈扁条状;氧硫化物与奥氏体基体之间弹性模量和热膨胀系数差别大;氧硫化物近旁产生应变场是晶内针状铁素体（IAF）形成的主要控制因素。     

Nucleation and three-dimensional morphology of intragranular ferrite in a vanadium microalloyed steel

The formation of intragranular ferrite at inclusions was analyzed by SEM-EDX in a vanadium microalloyed steel with an excess amount of sulfur. The precipitation of MnS at aluminum oxides may result in Mn depletion, which, in turn, promotes the formation of intragranular ferrite. The morphology of intragranular ferrite changed with undercooling. At higher temperatures intragranular ferrite is nearly equiaxed whereas it is plate-like at lower temperatures.     

Relaxation of Deformed Austenite and Refinement of Bainite in a Nb-Containing Microalloyed Steel

By means of stress relaxation and strain-induced precipitation in deformed austenite, bainite with micron sheaves size was ob-tained in Nb-containing steel. Microstructures of deformed samples isothermally relaxed for various time followed by cooling in water were examined. Stress relaxation test and transmission electron microscopy (TEM) were employed to detect precipitation of microalloy elements, such as Nb, Ti, during isothermal holding after deformation. All the samples were constituted by lath-like bainite along with acicular ferrite, but the size of bainitic sheaves and the amount of acicular ferrite were changed with relaxation time. To achieve optimum refinement, relaxation should be confined in the stage when the precipitates have sufficiently grown and started to coarsen. The sample having not undergone relaxation does not exhibit obvious refinement despite of its higher dislocation density. These results indicate that relaxation promotes bainite to refine, which is because deformed austenitic grains are divided by dislocation walls formed during rela-xation and acicular ferrite formed before bainitic transformation.     

07MnNiCrMoVDR钢焊缝组织与低温冲击韧性分析

采用SMAW焊接工艺焊接低合金高强度07MnNiCrMoVDR钢获得焊接接头,通过焊缝显微组织观察、冲击断口分析、焊缝低温冲击试验,研究了07MnNiCrMoVDR钢焊缝组织与低温冲击韧性。结果表明,焊缝组织由沿晶界分布的先共析铁素体、晶内的针状铁素体和粒状贝氏体构成,针状铁素体以微夹杂物为核心生长。温度为－40 ℃时,不同部位焊缝冲击吸收功随试样截取深度的增大而减小;与近表面处相比,1/2厚度处焊缝冲击吸收功损失约67%,在1/4厚度处,焊缝冲击吸收功随着温度的降低而降低;焊缝的低温冲击韧性符合要求。焊缝冲击断口的表面由凹凸不平变得比较平整,断口的微观形貌由韧窝花样变成解理河流花样。     

Precipitation and Hetero-nucleation Effect of V(C,N)in V-Microalloyed Steel

The precipitation behavior of V(C,N) in steels microalloyed with vanadium was researched using a thermal simulator during single-pass deformation at 800-750 ℃.The V(C,N) precipitates and its nucleation effect on ferrite were investigated by TEM and EDS.The experimental results show that there are two remarkable heterogeneous nucleation effects of V(C,N) particles precipitated before y→αphase change:primary reason is that high coherency between V(C,N) and ferrite promotes V(C,N) to become a nucleating center of intragranular ferrite;secondary reason is that the coarsening of V(C,N) causes locally solute-poor region in austenite,thus expedites the nucleation of intragranular ferrites further.Furthermore,the relationship between the size and shape of V(C,N)was studied,and identification method was provided for distinguishing interphase precipitation and general precipitation to avoid erroneous judgment and misguide.     

微合金非调质40Mn2V钢管的变形抗力研究

采用Gleeble-1500热模拟实验机对微合金非调质40Mn2V钢管的变形抗力进行了研究。结果表明,变形温度越高,变形速率越低,钢管变形抗力越小。变形抗力对数值lnσ随着温度升高和变形速率对数值ln ε的增大,分别呈线性减小和线性增大,且变形抗力与变形程度呈非线性关系。采用Matlab软件拟合出了微合金非调质40Mn2V钢管的变形抗力公式,其拟合度R为0．9663。     

Effect of austenitizing temperature on microstructure in 16Mn steel treated by cerium

The change of inclusions and microstructure of 16Mn steel treated by Ce were observed,and the effect of austenitizing temperature on the microstructure was also examined.The results show that the inclusions are transformed from Si-Mn-Al composite oxide and MnS into AlCeO3,Ce2O2S,and MnS composite inclusions after being treated by Ce.Plenty of intragranular ferrites are formed in 16Mn steel conraining ～0.017wt％ Ce.A large amount of intragranular acicular ferrites are formed after being austenitized for 20 min at 1473 K.The prior austenite grain size fit for the formation of intragranular acicular ferrites is about 120 μm.     

HYE36海洋石油钻井平台钢的试制

通过采用多元微合金化成分设计,LF＋VD复合精炼,TMCP控轧控冷、正火等一系列技术,开发了高强度高韧性HYE36海洋石油钻井平台用钢.试生产表明,所开发的HYE36钢从成分设计到工艺过程控制均比较合理,铸坯质量和钢板综合性能良好,可以满足用户要求.     

微合金化铸钢处理状态的综合评判

本文试图用数学方法,确切地评价和认定微合金化铸钢处理状态的最佳方案。结果说明,将层次分析法和Fuzzy综合评判方法相结合,是能够满意地解决综合评价材料的处理状态的。