中碳低铬多元合金衬板的研究

中碳低铬多元合金钢是一种综合性能较好的耐磨材料，经热处理后的金相组织为隐针马氏体＋下贝氏体＋少量残余奥低体，硬度ＨＲＣ５３－５７，冲击功为８０Ｊ，耐磨性是ＺＧＭｎ１３的３倍，将其用在球磨机衬板等铸件上，具有很大的推广价值。     

含钒高铬铸铁衬板的研制

研究了采用铸态速冷方法获得的ＫｍＴＢＣｒ１５ＷＶＴｉ铸铁的特性，以及钒含量对其组织，机械性能，耐磨性的影响。结果表明：用该材料制得的烧结机衬板，在常温部位作用，其寿命是ＺＧ５０Ｍｎ２ＣｒＭｏＶ烧结机衬板的４－６倍，取得了较大的经济效益。     

反击式破碎机锤头新材质研制

研制出ＺＧＣｒＭｎＣｕ反击式破碎机锤头，经装机试验，其使用寿命为现役锤头（Ｍｎ１３）的５倍，硬度值ＨＲＣ达５３，冲击韧性ａｋ值达２４Ｊ／ｃｍ＾２。     

中碳马氏体耐磨铸钢的研究与应用

本文通过利用ＲＥ－Ｂ复合变质剂，变质处理ＺＧ３０ＣｒＭｎ２Ｓｉ，使其性能，特别是韧性明显提高，无缺口试样的ａｋ≥１００Ｊ／ｃｍ＾２，为用来制作破碎中等硬度物料的耐磨件提供了可靠的依据。     

热处理工艺和爆炸预硬化对高锰钢ZGMn13VTiMoRE组织和耐磨性的影响

运用金相、透射及扫描电镜和冲蚀磨损等试验方法，研究了不同水韧及时效工艺处理和爆炸预硬化对高锰钢组织和耐磨性的影响，提出了优化热处理工艺。研究结果表明，经优化热处理工艺和爆炸预硬化处理后，使ＺＧＭｎ１３ＶＴｉＭｏＲＥ钢得到细小，均匀的奥氏体晶粒，弥散分布的第二相质点，一定厚度的预硬化层和存在于基体中的大量形变层错及孪晶等，其耐磨性可提高４０％。     

矿石,钢球,球磨机衬三者硬度对磨矿效率的影响

西方详细阐述了根据矿石硬度正确选用不同硬度的钢球和球磨机衬板，可以获得最低的单耗和最好的球磨机单机自理量。对高硬度矿石如何选用钢球，衬板提出了几点看法。     

少量Mn对Cu—15Ni—8Sn合金时效硬化的影响

本文对真空熔铸含Ｍｎ量为０．４６ｗｔ％的Ｃｕ－１５Ｎｉ－８Ｓｎ合金的时效硬化，形变时硬化过程及其组织变化作了研究。实验证明：（１）０．４６ｗｔ％Ｍｎ固溶于Ｃｕ－１５Ｎｉ－８Ｓ合金中；（２）含少量Ｍｎ的合金的时效硬化，形变时效硬化及组织变化的基本特征与不含Ｍｎ的Ｃｕ－１５Ｎｉ－８Ｓｎ的合金相类似，但少量Ｍｎ延缓合金的时效，形变时效过程，增加硬化效果。     

中碳低铬多元合金钢衬板的研究

中碳低铬多元合金钢是一种综合性能较好的耐磨材料，经热处理后的金相组织为隐针马氏体十下国氏体十少量残余奥氏体，硬度ＨＲＣ５３～５７，冲击功为８０Ｊ，耐磨性是ＺＧＭｎ１３的３倍，将其用在球磨机材板等铸件上，具有很大的推广价值。     

少量Mn对Cu－15Ni－8Sn合金时效硬化的影响

本文对真空熔铸含Ｍｎ量为０．４６ｗｔ％的Ｃｕ－１５Ｎｉ－８Ｓｎ合金的时效硬化、形变时效使化过程及其组织变化作了研究。实验证明：（１）０．４６ｗｔ％Ｍｎ固溶于Ｃｕ－１５Ｎｉ－８Ｓｎ合金中，（２）含少量Ｍｎ的合金的时效硬化、形变时效硬化及组织变化的基本特征与不含Ｍｎ的Ｇｕ－１５Ｎｉ－８Ｓｎ合金相类似，但少量Ｍｎ延缓合金的时效、形变时效过程，增加硬化效果。     

残余奥氏体的磨损硬化能力

采用显微硬度和Ｘ射线分析,研究了Ｍｎ－Ｃｕ－Ｍｏ白口铸铁中残余奥氏体（γＲ）的磨损硬化能力。结果表明：磨损面的显微硬度显示了γＲ固有的磨损硬化能力,其实质是γＢ晶粒内存在着微观应变、高密度位错以及亚晶和胞状亚结构。而γＲ的相变强化与磨损状况密切相关。     

耐高温耐磨抗冲击花格子的研究与应用

通过改变衬板结构形式和优化材质两个方面,研究了一种可在高温、高落差、高硬度物料运输过程中替代环冷机布料漏斗内衬板的耐高温耐磨抗冲击花格子。结果表明,将该花格子应用在单辊破碎机溜槽后,单辊破碎机溜槽的使用寿命至少提高了3倍,有效降低了破碎机溜槽的故障率,提高了烧结机的作业率,每年创效216.88万元以上。     

Comparison of the microstructures and abrasive wear properties of stellite hardfacing alloys deposited by arc welding and laser cladding

The microstructure of cobalt-based hardfacing alloys deposited by manual metal arc (MMA) welding, tungsten inert gas (TIG) welding, and laser cladding has been investigated as part of a study attempting to establish the relationship between microstructure and abrasive wear properties. For typical deposition conditions, the differences in freezing rates associated with the three processes are found to give rise to large differences in microstructure. The MMA process is found to lead to the largest degree of dilution of the hardfacing deposit; the TIG and laser deposits exhibited much lower levels of mixing with the base plate. For the deposition conditions used in this study and for the alloys examined, the scale of the microstructure decreases in the order MMA, TIG, and laser cladding, leading to an increase in the deposit hardness in the same order. It is found that with alumina as an abrasive, the wear rate persistently is higher with the MMA deposits (which have the coarsest microstructure with the lowest starting hardness), the weight loss being approximately linear with time. The laser and TIG deposits, which have more refined microstructures and slightly higher carbon concentrations, both are found to exhibit significantly lower wear rates. Initially, the TIG samples are the most resistant to abrasion, even though their microstructure compares with that of the laser samples; this is a consequence of their higher ductility associated with a lower rate of strain hardening. The laser samples, which contain a lower matrix iron concentration, strain harden more rapidly; consequently, they exhibit an initial decrease in wear rate. With the much harder silicon carbide abrasive, all samples show similar wear rates which do not decrease with time. The wear data are found to correlate with scanning and transmission electron microscopy observations, and it is possible to rationalize the interaction among microstructure, abrasive, and alloy deposition processes.     

中碳低合金钢的组织性能及应用效果

本文采用不同的淬火介质,调整C,Mn,Cr,Cu四种合金元素的含量,用正交试验法优选出较理想的组织和性能,以较佳的工艺方案制出球墨机衬板,其使用寿命是高锰钢衬板的1．5倍多。     

2Cr13冷作硬化板轧制工艺研究

2Cr13冷作硬化板开发的难度主要在硬度要求及板形控制两方面。通过对轧制工艺的优化，在生产中成功地解决了这两大难题．该产品的成功开发，在创造可观的经济效益的同时，也为我厂2Cr13板材的生产开辟了新的途径，具有较好的市场前景。     

Bake Hardening of Laser Welded Dual Phase Steel

The influence of bake hardening on the mechanical properties of laser welded dual phase steel was investigated. A remarkalbe increase of the hardness in the zone influenced by laser welding was observed. The fusion zone had a low carbon lath martensite microstructure. The laser weld region had a higher interstitial carbon content than the base material. The dual phase steel exhibited a clear bake hardening effect in both the as‐received and the laser‐welded conditions. The bake hardening effect is more pronounced in the prestrained laser welded condition. A pronounced decrease of the ductility was observed for prestrained laser welded DP steel.     

制样方法对IF钢纳米压入测试结果的影响

 对3种不同方法制备的IF钢试样进行了纳米压入表征,分析了制样方法对IF钢中铁素体纳米压入测试结果的影响。结果表明,制样方法对铁素体杨氏模量平均值影响不大,但对硬度平均值影响显著,机械抛光和机械抛光+化学侵蚀状态铁素体的硬度均高于机械抛光+电解抛光状态的铁素体。这主要是因为机械抛光对试样表面造成了明显的加工硬化层,而化学侵蚀处理不能完全去除硬化层,只有电解抛光才能起到有效消除硬化层的作用。机械抛光+电解抛光处理更有利于IF钢的纳米压入表征。     

我国Mn13轧制耐磨钢板的开发生产与应用

Mn13钢种在受到强烈的冲击或较大挤压载荷作用下,表面会瞬时产生加工硬化。随着这种硬化效果的快速积累,钢板表面的硬度迅速升高,而钢的基板始终保持奥氏体钢良好的冲击性能。目前Mn13广泛应用于我国机械设备制造中,是用途最广、用量最大的耐磨钢品种。Mn13轧制钢板现在尚处于推广发展的阶段,正逐步成为替代高锰钢铸件等品种的新一代材料。重点阐述了Mn13轧制钢板的生产工艺、产品用途和生产应用的建议。     

Bauschinger effect in Nb and V alloyed line-pipe steels

Abstract

The UOE process is used for cold forming of large diameter steel line-pipes. Pipe strength has been found to increase (work hardening) or decrease (Bauschinger effect) after the UOE process compared to the plate depending on the steel grade, plate and pipe processing history. The steel chemistry, through the presence of microalloy precipitates, and prior processing, through the size and distribution of microalloy precipitates and presence of retained work hardening, affects the magnitude of the Bauschinger effect. In this paper the microstructures of two (Nb and Nb–V alloyed) steel plates, in terms of (Nb,V)(C,N) particle distributions and dislocation densities, have been related to the Bauschinger parameters in the as rolled and annealed initial conditions. The Bauschinger stress parameter increases with microalloy particle number density and dislocation density increase and the relative importance of the two effects is discussed.     

Modeling the Case Hardening of Automotive Components

A generalized framework has been developed within ABAQUS to model the surface hardening heat treatment processes for automotive steel components. The macro-scale heat transfer and stress calculations during the heating and quenching are coupled with the microstructural phase calculations, defined through a user routine, to estimate key process parameters such as case depth and surface hardness. This model has been applied to predict these parameters in two key industrial processes, i.e., case hardening of crankshafts and case carburization of gears. The results of the case depth and hardness calculations have been validated with the literature and in-house plant data. The effect of varying quench conditions on the overall stress distribution changes within the component has been outlined.     

Microstructural modifications in an explosively welded Ti/Ti clad material: I. Bonding interface

Microstructural modifications of the bonding interface in an explosively welded Ti/Ti clad material using the preset angle standoff configuration with various flyer plate speeds have been studied. Explosive welding was completed at flyer plate speed over 420 m/s. The wavelength and amplitude of the wavy interface increased with increasing flyer plate speed up to 1060 m/s. The planar interface was obtained at flyer plate speed of 1150 m/s. The trace of melting was observed at the bonding interface in the present experimental conditions. It is concluded that the melting layer is responsible for the bonding of explosively welded Ti/Ti clad materials. An anomaly hardening zone was formed at the bonding interface in the clad material welded at flyer plate speed of 1150 m/s. The origin of the observed anomalous hardening has also been discussed. H. MINATO and J. SHUDO, formerly Graduate Students, Department of Materials Science and Resource Engineering, Kumamoto University.