无碳化物贝氏体耐磨钢板组织与性能的研究

研究了无碳化物贝氏体耐磨钢板组织、力学性能及焊接性能。结果表明,在低碳贝氏体钢基础上,通过加入一定量的硅元素,利用其在贝氏体组织转变过程中抑制碳化物析出作用,得到由非等轴铁素体加马氏体和残余奥氏体(M-A)岛或由板条状铁素体及其板条间残余奥氏体(Ar)膜组成的无碳化物贝氏体组织,以此得到既具有高强度、高硬度,又具有较高的低温冲击韧性,同时具有较好的焊接性能。     

准贝氏体组织及新型系列准贝氏体钢

新型钢中的准贝氏体由贝氏体铁素体和分布其上的残余奥氏体膜组成,处于贝氏体转变的初期阶段。新型准贝氏体钢具有优异的综合力学性能和简单易行的工艺性能,应用前景广阔。     

包钢NM400级高强度耐磨钢板问世

目前,包钢与北重集团签署协议,包钢生产的NM400级高强度耐磨钢板获准用在北重矿山用载重汽车上,此举标志着包钢NM400级高强度耐磨钢板研发取得了巨大突破。当前,国内现有耐磨钢的产能远远不能满足市场需求,特别是HB400以上强度级别的耐磨钢大量依赖进口。     

一种新型贝氏体组织的研究

作者研制的新型高碳硅锰低合金超高强度钢,经280～360℃等温处理,获得一种新型贝氏体组织——板条束状过饱和铁素体与薄膜状富碳奥氏体交替排列的奥氏体—贝氏体双相组织。本文从组织结构特征及转变温度等方面对新型贝氏体与常见的贝氏体组织进行了分析对比,探讨了钢的化学成分及转变温度对贝氏体组织结构的影响。     

一种超高强度贝氏体钢的研制

设计了一种具有优良综合力学性能的中碳Ｓｉ－Ｍｎ－Ｍｏ系超高强度贝氏体钢。给出了成分－性能关系，测定了ＣＣＴ图，考察了低温回火对性能的影响。组合分析表明，该钢在轧态下是一类以无碳化物的特殊贝氏体－准贝氏体为主的组织，此种组织的获得是设计钢种具有超高强度及良好韧塑性配合的主要成因。     

新型耐磨贝氏体钢的研制及应用

采用廉价的硅锰元素为主合金化，开发空冷贝氏体耐磨钢。新钢种在获得高强度和硬度的同时，可保证有较高的韧性。贝氏体组织中板条间膜状奥氏体是保证该钢有强韧性配合的原因。该钢种制造的磨球、锤头、颚板工业应用表面其具有良好的使用效果，是一种值得推广的新钢种。     

贝氏体抽油杆钢性能的研究

介绍了FG20高强度抽油杆钢的化学成分、热处理工艺、力学性能、组织特点及强韧化机理。在FG20钢的成分基础上通过去钒提钛和降低碳、锰含量提高硅含量两种方式调整化学成分，使试验钢得到典型的粒状贝氏体组织，与FG20钢相比，抗拉强度差别不大，而伸长率和断面收缩率明显提高。通过降低回火后冷却速度和时效处理两种热处理工艺，使FG20钢伸长率和断面收缩率显著提高。     

1500MPa级超高强度耐磨钢板淬透性改善工艺实践

针对1 500 MPa级超高强度耐磨钢板淬透性不足的问题,利用微观组织分析的方法,对问题产生原因从淬火温度、保温时间、化学成分、冷却速度等角度进行了分析和研究。通过优化成分、改善热处理条件等措施提高淬透性,实现了批量生产,产品实物质量得到极大提升。     

无碳化物贝氏体组织与性能的研究

研究了无碳化物贝氏体的组织与机械性能。结果表明，在低碳贝氏体钢基础上，通过加入一定量的硅元素，利用其在贝氏体组织转变过程中抑制碳化物析出作用，得到由非等轴铁素体加马氏体和残余奥氏体(M—A)岛或由板条状铁素体及其板条间残余奥氏体(Ar)膜组成的无碳化物贝氏体组织，既具有高强度、高硬度，又具有较高的低温冲击韧性。     

Effect of Heat Treatment on Microstructure and Mechanical Properties of HB400 Grade High Strength Abrasion Resistant Steel

High strength abrasion resistant steel plates are widely used in mining,construction and agricultural machineries.The plates are,however,usually poor in impact toughness.An attempt is made to improve the impact toughness of HB400 grade abrasion resistant steel by controlling quenching and tempering of the plates.Optimized combination of the strength and the toughness has been achieved by choosing best fit set of quenching and tempering condition.Mechanism underlying the achievement has been investigated in terms of the microstructure consisting of tempered lath martensite,retained austenite and precipitated carbides.     

稀土对低合金耐磨铸钢组织和性能的影响

采用扫描电镜分析,硬度测试和摩擦性能测试等手段,研究了稀土对低合金耐磨铸钢组织和性能的影响。结果表明,在低合金耐磨铸钢中添加0.15%稀土,可细化合金铸态组织,增加铸态组织中的铁素体数量,减少珠光体数量,同时可细化热处理后合金的贝氏体组织,使铁素体形态和大小分布均匀,马氏体数量减少。添加稀土后可使铸态合金硬度提高9.4%,摩擦系数由0.136 9减小为0.081 9。     

HB450低合金超高强耐磨钢回火过程中的组织性能演变

  利用透射电镜（TEM）、扫描电镜（SEM）等试验方法,研究了新型低成本HB450低合金超高强耐磨钢在不同回火条件下组织和性能演变规律,并分析了其强韧变化机制。结果表明：回火对试验钢的硬度和强度均有较大影响。在200~250℃回火,试验钢表现出良好的强韧性配合,满足国标工程机械用高强度耐磨板GB/T24186—2009中NM450级别要求;在250℃回火时,试验钢出现硬化迹象。透射电镜分析表明,在该温度下回火,析出物中除了有大量弥散分布的ε 碳化物外,还出现了少量30~50nm的（Nb,Ti）（C,N）粒子,该2类粒子对试验钢的强化起着较大的作用。     

大厚度420MPa级高性能钢板的组织控制及性能均匀性

研究了不同合金成分对大厚度尺寸高性能钢板力学性能的影响,对比研究了30、60、80 mm厚钢板中心部和1/4厚度处的组织和性能的均匀性,通过适当的合金化和/或回火工艺可改善大厚度尺寸钢板心部力学性能,使大厚度钢板的组织性能更均匀化,并且使60~80 mm厚度的钢板的心部强度达到420 MPa以上。     

Mechanical Properties and Microstructure of X120 Grade High Strength Pipeline Steel

A new ultrahigh strength pipeline steel with high yield strength and high impact toughness was fabricated in this work,and mechanical properties and microstructure of the steel were investigated.The steel exhibited outstanding mechanical properties with yield strength levels of up to 951 MPa and tensile strength levels up to 1023 MPa.The sharp notch toughness with absorbed energy values of 227 J/cm2 at-30 ℃ and shear area of up to 95% in drop weight tear test(DWTT)at temperature of-20℃ were achieved.It was found that microstructure of the steel comprises a majority of low-carbon lath bainite with different sublaths and sub-sublaths,meanwhile there is a high density of dislocation between laths and the dispersed film-like martensite-austenite(M-A)constituents.Most of the precipitates in this steel are duplex type containing Nb and Ti with characterized morphology of cap with the range of precipitation size from a few to tens nanometers.     

高强度低合金耐磨钢NM400的强韧化机制

采用控轧控冷工艺生产的高强度低合金耐磨钢NM400,具有高强度、高硬度和较高的韧性,其屈服强度为1 170MPa,抗拉强度为1 369MPa,平均硬度为403HB,伸长率为23%,-20℃冲击功为47J。光学显微镜观察发现,NM400的组织为回火马氏体,淬透性良好;透射电镜下观察发现,钢中存在大量纳米尺寸级析出物,能谱分析表明,析出物为Ti,Nb的碳氮化物。分析结果表明,耐磨钢NM400的强化机制主要为位错强化、细晶强化和析出强化;细晶强化是韧性提高的主要原因。     

Microstructure and Mechanical Properties of Precipitation Strengthened Fire Resistant Steel Containing High Nb and Low Mo

Through the thermo-mechanical control process(TMCP),a high Nb low Mo fire resistant steel with the yield strength(YS)of 521 MPa at room temperature(RT)and 360 MPa at elevated temperature(ET)of 600 ℃was developed based on MX(M=Nb,V,Mo;X=C,N)precipitation strengthening.A series of tensile and constant load tests were conducted to study the mechanical properties at ET.The dynamic continuous cooling transformation(CCT)as well as precipitation behavior of microalloy carbonitride was investigated by means of thermal simulator and electron microscopy approaches.Results showed that the failure temperature of tested steel was determined as 653 ℃,and the granular bainite was obtained when the cooling rate was higher than 10 ℃/s.In the rolled state,a certain amount of M/A islands was observed.During heating from RT to ET,M/A islands disappeared,and cementites and high dense compound precipitates(Nb,Mo,V)C with size of less than 10 nm precipitated in ferrite at ET(600 ℃),which resulted in precipitation strengthening at ET.     

Effects of Al on Microstructure and High-Temperature Wear Properties of Austenitic Heat-Resistant Steel

 Microstructure and high-temperature dry sliding wear at 600 ℃ in ambient air of austenitic heat-resistant steel ZG40Cr25Ni20 with different contents (mass percent) of Al (0 to 710%) have been investigated. The results show that microstructures of 468% and 710% Al addition content consist of the matrix and reinforcement of intermetallic compound γ′ and carbide, while microstructures of ZG40Cr25Ni20 without Al and with Al of 168% are absent of γ′. Higher wear resistance than the original ZG40Cr25Ni20 alloy is achieved in alloys with higher content of Al under the same high-temperature wear test condition. The wear rates of Fe-25Cr-20Ni-710Al and Fe-25Cr-20Ni-468Al are only 2083% and 4583% of that of Fe-25Cr-20Ni, respectively. Heat-resistant steels with higher contents of Al (472% and 710%) have higher hardness than those with lower contents of Al (168% and 0). Wear mechanisms of ZG40Cr25Ni20 are considered as severe plough plastic deformation and slight adhesive. However, wear mechanisms of Fe-25Cr-20Ni-468Al are light micro-cutting and oxidation-wear, while that of Fe-25Cr-20Ni-710Al are severe adhesive transfer and oxidation-wear.