新型高强高韧钢G99的穆斯堡尔谱研究

测量了Ｇ９９钢淬火、退火及不同温度回火态的穆斯堡尔谱，分析了超精细场与合金元素分布之间的关系以及对力学性能的影响。研究结果表明，Ｇ９９钢的超精细场随回火温度的升高而变化，除回火过程中相间的转变外，主要是由合金元素Ｃｏ和Ｎｉ原子的扩散所引起的。Ｃｏ、Ｎｉ原子分布的变化对该钢的力学性能有一定影响。     

新型高强高韧钢G99的穆斯堡尔谱研究

测量了Ｇ９９钢淬火，退火及不同温度回火态的穆斯堡尔谱，分析了超精细场与合金元素分布之间的关系以及对力学性能的影响。研究结果表明，Ｇ９９钢的超精细场随回火温度的升高而变化，除回火过程中相间的转变外，主要是由合金元素Ｃｏ和Ｎｉ原子的扩散所引起的。     

奥氏体型Fe—Cr—Mn（M,V）合金相稳定性研究

通过形变加工和长期时效热处理，研究了（Ｃ＋Ｎ）复合强化的Ｆｅ－１３Ｃｒ－１７Ｍｎ（Ｍ，Ｖ）奥氏体合金的稳定性和相平衡特点，结果表明：在５００℃以下合金奥氏体稳定，不发生γ→α转变。采用（Ｃ＋Ｎ）复合添加晶粒细化，可有效抑制ε马氏体形成和σ相析出。５００～７００℃长期时效后形变诱发大量碳化物析出，Ｍｓ点提高，加快形变诱发α马氏体分解和再结晶，促使γ→α转变和σ相析出，合金奥氏体变得不稳定。     

高合金奥氏体铸造不锈钢析出相及腐蚀行为的研究

高合金奥氏体不锈钢铸态组织中有σ相存在，经８５０～１１２０℃热处理所形成的σ相包括：（Ｆｅ－Ｃｒ）σ相、（Ｆｅ－Ｍｏ）σ相、以及（ＣｒＮｉＳｉ）σ相。８５０℃左右有Ｍ６Ｃ型碳化物和ＮｂＣ析出。该钢经１１５０℃×２ｈ水冷固溶处理后，具有优良的抗均匀腐蚀、晶间腐蚀、点蚀和化学腐蚀性能。     

W6Mo5Cr4V2钢形变诱发析出碳化物及规律

对Ｗ６Ｍｏ５Ｃｒ４Ｖ２钢经１２４０℃奥氏体化后于１７０－１１５０℃形变０－６５％直接淬火过程中诱发析出的碳化物进行了研究。结果表明，在７５０－１１５０℃热形变淬火迁程中均诱发析出直径约１－２μｍ，具有立方ＮａＣｌ晶型的ＭＣ型碳化物；碳化物的分在民形变温度有关，高温形变呈随机分布，而低温下则趋于沿Ｆ１１１Ｇγ滑移面析出呈方向性分布；碳化物的析出量主要由形变温度和该表变温度下热变形奥氏体的组织状态...     

EFFECT OF PRESSURE ON GRAIN SIZE OF CRYSTALLIZED PHASE α-Fe(Mo,Si)IN AMORPHOUS (Fe_(0.99)Mo_(0.01))_(78)Si_9B_(13)ALLOYS

在压力为３－６ＧＰａ和温度为７２３－９３３Ｋ范围内，对非晶（Ｆｅ０．９９Ｍｏ０．０１）７８Ｓｉ９Ｂ１３合金等温晶化形成的纳米α－Ｆｅ（Ｍｏ，Ｓｉ）晶粒尺寸随温度和压力的变化进行了研究。发现其晶粒尺寸随压力变化主要取决于压力对成核速率手影响，其根本原因是压力对熔点的作用。     

WC—8（Fe／Ni／Co）R硬质合金的研究

用Ｆｅ、Ｎｉ部分取代ＷＣ－８Ｃｏ合金（牌号ＹＧ８）中的粘结剂Ｃｏ,再添加微量稀土Ｒ制得ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金,测试了其物理机械性能,研究了粘结剂各种成份比例及烧结温度对硬质合金的影响。结果表明：ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金的性能可以达到ＹＧ８的性能标准。利用扫描电镜（ＳＥＭ）及Ｘ射线衍射（ＸＲＤ）对其作了显微结构分析,同时探讨了影响ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ合金性能的     

18Ni马氏体时效钢时效机理的研究

采用小角Ｘ射线散射、Ｍｏｓｓｂａｕｅｒ谱、透射电镜等方法研究了１８Ｎｉ马氏体时效钢的时效过程。结果表明，１８Ｎｉ合金在固溶处理后５００℃等温时效过程中，首先发生调幅分解，然后在调幅组织的Ｎｉ－Ｍｏ－Ｔｉ富集区以原位形核方式析出含Ｆｅ的Ｎｉ３（Ｍｏ、Ｔｉ）型金属间化合物，随时效时间延长，Ｎｉ３Ｍｏ和Ｎｉ３Ｔｉ粒子聚集长大并部分溶解，同时析出球形Ｆｅ２Ｍｏ金属间化合物，并形成逆转变奥氏体。     

化学镀Fe—Mo—W—B非晶态合金的晶化

利用化学镀获得非晶态Ｆｅ－Ｍｏ－Ｗ－Ｂ四元合金镀层。用Ｘ射线衍射方法研究了镀层的结构和晶化过程。结果表明;Ｂ含量在９．８ａｔ％－２７．３ａｔ％范围内镀层为非晶态结构,该区域大于Ｆｅ－Ｂ二元合金镀层,但不如Ｆｅ－Ｍｏ－Ｂ三元合金镀层。观察到两步晶化过程：首先析出的晶化相为α－Ｆｅ,Ｆｅ３Ｂ和（Ｍｏ,Ｗ）２Ｂ;然后在较高温度出现Ｆｅ２Ｂ,（Ｍｏ,Ｗ）Ｂ和Ｆｅ（Ｍｏ,Ｗ）的衍射峰。     

高纯度Fe—C—Mo合金贝氏体相变和形貌特征

研究了高纯度Ｆｅ－０．０６％Ｃ－１．８％Ｍｏ和Ｆｅ－０．１９Ｃ－１．８１％Ｍｏ合金恒温贝氏体转变。结果表明，５５０－５８０℃转变是完全的。两种合金分别在６００℃和５８５℃左右保温时，转变中途会出现暂时停滞现象，而后恢复并加快转变。两合金ＴＴＴ图均有一明显稳定区。７５０℃保温形成铁素体和平行于奥氏体晶界的片状或杆状碳化物沉淀。７００－６００℃保温在较高碳量和钼量形成少量节瘤状贝氏体，７００℃保温转变     

ON THE STRENGTHENING MECHANISM OF HIGH Co-Ni ULTRAHIGH STRENGTH STEEL

ＯＮＴＨＥＳＴＲＥＮＧＴＨＥＮＩＮＧＭＥＣＨＡＮＩＳＭＯＦＨＩＧＨＣｏ－ＮｉＵＬＴＲＡＨＩＧＨＳＴＲＥＮＧＴＨＳＴＥＥＬＢ．Ｌｉｎｇ;Ｐ．Ｚｈｏｎｇ;Ｂ．ＷＺｈｏｎｇ;Ｚ．ＹＺｈａｏａｎｄＳ．Ｑ．Ｚｈａｎｇ（ＢｅｉｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＡｅｒ...     

回火温度对7Ni钢组织和性能的影响

利用OM、SEM、TEM和XRD试验方法,分析在两相区淬火+回火(QLT)工艺中,不同回火温度下7Ni钢组织形貌和逆转变奥氏体含量的变化,研究回火温度对7Ni钢低温强度和低温韧性的影响。结果表明:随着回火温度升高,7Ni钢抗拉强度逐渐提高,而低温韧性呈现先升高后降低的趋势。回火温度从560 ℃提高到620 ℃过程中,7Ni钢马氏体组织由粗大转变为均匀弥散细小,抗拉强度逐渐提高。当回火温度较低时,钢中马氏体回复不充分,析出的逆转变奥氏体量较少,低温韧性偏低。随着回火温度升高,7Ni钢逆转变奥氏体含量不断升高,但稳定性下降,大量不稳定的逆转变奥氏体在低温下发生转变,不利于钢低温韧性的改善。7Ni钢低温韧性随着回火温度升高呈现先升高后降低的趋势,并在580 ℃时获得最好的低温韧性。     

Elevated-temperature properties of one long-life high-strength gun steel

The hardness, tensile strength and impact toughness of one quenched and tempered steel with nominal composition of Fe-0.25C-3.0Cr-3.0Mo-0.6Ni-0.1Nb (mass fraction) both at room temperature and at elevated temperatures were investigated in order to develop high-strength steel for long-life gun barrel use. It is found that the steel has lower decrease rate of tensile strength at elevated temperature in comparison with the commonly used G4335V high-strength gun steel, which contains higher Ni and lower Cr and Mo contents. The high elevated-temperature strength of the steel is attributed to the strong secondary hardening effect and high tempering softening resistance caused by the tempering precipitation of fine Mo-rich M2C carbides in the aaaaaaaaaaaaaaaa-Fe matrix. The experimental steel is not susceptible to secondary hardening embrittlement, meanwhile, its room-temperature impact energy is much higher than the normal requirement of impact toughness for high strength gun steels. Therefore, the steel is s     

On the formation of the structure of a carburized layer during cementation of a low-carbon martensitic steel 12Kh2G2NMFT

The process of production and subsequent strengthening of a gradient carburized layer on a low-carbon martensitic steel 12Kh2G2NMFT has been investigated. It has been shown that the structure and properties of the carburized layer and of the base of the steel can be optimized by quenching from the intercritical temperature range after a preheating or high-temperature tempering. In the carburized layer, reverted austenite with a high hardness equal to or even exceeding the hardness of martensite has been obtained. The strengthening of the austenite occurs due to the precipitation of dispersed carbides during heat treatment following cementation.     

Effect of single and double austenitization treatments on the microstructure and mechanical properties of 16Cr-2Ni steel

Double austenitization (DA) treatment is found to yield the best combination of strength and toughness in both low-temperature as well as high-temperature tempered conditions as compared to single austenitization (SA) treatments. Obtaining the advantages of double austenitization (DA) to permit dissolution of alloy carbides without significant grain coarsening was attempted in AISI 431 type martensitic stainless steel. Structure-property correlation after low-temperature tempering (200 °C) as well as high-temperature double tempering (650+600 °C) was carried out for three austenitization treatments through SA at 1000 °C, SA at 1070 °C, and DA at 1070+1000 °C. While the increase in strength after DA treatment and low-temperature tempering at 200 °C is due to the increased amount of carbon in solution as a result of dissolution of alloy carbides during first austenitization, the increased toughness is attributable to the increased quantity of retained austenite. After double tempering (650+600 °C), strength and toughness are mainly found to depend on the precipitation and distribution of carbides in the microstructure and the grain size effect.     

回火温度对Cr5NiMoVNb支承辊用钢组织与性能的影响

为了研究回火温度对Cr5NiMoVNb支承辊用钢显微组织及力学性能的影响,采用扫描电镜、X射线衍射仪、洛氏硬度计、拉伸试验机和冲击试验机对不同回火温度下Cr5NiMoVNb钢进行了测试.结果表明:Cr5NiMoVNb钢的回火态组织以回火马氏体为主,并含有少量的残留奥氏体.回火过程中伴随有碳化物的析出和马氏体相变.随着回...     

淬火冷却工艺对F460钢调质厚板组织与性能的影响

对120 mm厚的F460钢调质厚板采用相同的淬火回火温度,不同的淬火冷却速度处理,之后对钢板进行组织与性能对比,寻找该钢种的最佳热处理工艺。采用2 ℃/s冷速进行冷却的钢板,回火后强度最高,但是冲击性能不佳;适当降低淬火冷却速度后,钢板回火后强度有一定下降,但是冲击性能得到明显提升;继续降低淬火冷却速度,钢板回火后强度进一步下降,但是冲击性能提升有限。经组织分析,2 ℃/s冷速进行冷却淬火时,钢板回火后的组织为铁素体+贝氏体组织,组织中主要是贝氏体;冷却速度降低以后,钢板回火后组织为铁素体+退化珠光体组织,铁素体含量的增加,有利于钢板韧性的提升,残留奥氏体回火后形成的珠光体组织比较细小,能有效保证钢板的强度。通过对钢板的连续冷却转变曲线进行分析,钢板在冷却过程中先开始进行铁素体相变,溶质元素向奥氏体迁移。在钢板冷速较快时,铁素体中的碳化物迁移较少,奥氏体低温时转变成马氏体或者贝氏体;在钢板冷速较慢时,碳化物迁移到奥氏体内,提高奥氏体稳定性并保留到室温,形成残留奥氏体。残留奥氏体在后续的高温回火过程中,转变成珠光体。块状转变形成的铁素体组织与回火过程中形成的细小珠光体有利于钢板的强韧性匹配。     

SECONDARY HARDENING OF BAINITE IN HIGH SPEED STEEL

The mechanical properties and structure of bainite and martensite after tempering m 6-5-4-2high speed steel have been investigated.It was found that the secondary hardening effect andresistance to heat softening as well as impact toughness are higher in the bainite than in themartensite.TEM observations show that the(Fe,M)_3C precipitated in the martensite aftertempering at temperature near the peak of hardness-tempering temperature curve.However,no(Fe,M)_3C but the dispersive MC and M_2C precipitated in the ferrite and austenite ofbainite after tempering at the same temperature.This indicates that the diffusion of alloy ele-ments forming carbide might exist during the process of bainite growing.     

新型铸造热锻模具钢强韧性本质的探讨

采用微观分析方法探讨了新型铸造热锻模具钢（CHD钢）的强韧化机理,研究表明,CHD钢具有较高的强韧性和高温稳定性,其组织为具有高密度位错的板条马氏体和贝氏体的复合组织,板条界连续分布着许多薄膜状残留氏体,CHD钢在回火过程中弥散析出细小的碳化物V3C4,Mo2C,这些亚结构的配合是CHD钢具有高强韧性的本质。