A Review of Influencing Factors of Damping Properties of High Manganese Steel

High manganese steel has wide prospects in industry due to their excellent mechanical and damping properties. The quenching structures of high manganese steel are ε-martensite, γ-austenite and α'-martensite. Researches show that the damping properties of high manganese steel are related to these microstructures. Besides, there are many ways to improve the damping property of damping alloys. This paper reviews the damping mechanism and the influences of the ad-dition of alloying elements, heat treatment, pre-deformation and other factors on their damping performance, hoping to provide methods and ideas for the study of damping properties of high manganese steel. .

WELDING BETWEEN HIGH MANGANESE STEEL AND HIGH CARBON STEEL

Manuscript received 30 July 1999 Abstract The shielded metal arc welding (SMAW) of a manganese steel part as a crossing of railway track to a carbon steel part as the rails of the railroad is the welding of dissimilar steel. It are was known that it is not possible to the the rail of railroad directly to the cross- ing of railway track made from a steel containing about 14% of manganese (wt. ) because of so many differences between the two kinds of steels such as composition, microstructure,mechanical properties and weldability.A method was used to solve the problem by presetting an intermediate layer on each side of the joint and other special procedures were used.The result of test indicated that a good weld joint was obtained.

NUMERICAL SIMULATION OF TEMPERATURE FIELD ON FLASH BUTT WELDING FOR HIGH MANGANESE STEELS

An axial symmetry finite element model coupled with electricity-thermal effect was developed to study the temperature field distribution in process of the flash butt welding （FBW） of frog highmanganese steel. The influence of temperature dependent material properties and the contact resistance were taken into account in FEM ＇simulation. Meanwhile, the lost materials due to .splutter was resolved by using birth and death element. The result of analyzing data shows that the moddel in the FBW flashing is reasonable and feasible, and can exactly simulate the temperature field distribution. The modeling provides reference for analysis of welding technologies on the temperature field of high-manganese steel in FBW.

Influence of Impact Energy on Impact Corrosion-abrasion of High Manganese Steel

The impact corrosion-abrasion properties and mechanism of high manganese steel were investigated under different impact energies. The result shows that the wearability of the steel decreases with the increase of the impact energy. The dominant failure mechanism at a lower impact energy is the rupture of extrusion edge along root and a slight shallow-layer spalling. It transforms to shallow-layer fatigue flaking along with serious corrosion-abrasion when the impact energy is increased, and finally changes to bulk flaking of hardened laver caused by deeo work-hardening and heaw corrosion-abrasion.

Effect of RE-Modifier on Microstructure and Mechanical Property of High-Carbon Medium-Manganese Steel

The effect of RE-modifier on the microstructure and mechanical properties of high carbon-medium manganese steel has been investigated in present work.The results showed that the RE-modifier can refine the crystalline grain of high-carbon medium-manganese steel.The shape and distribution of carbides are improved and the columnar grains and phosphide in grain boundary are eliminated.Consequently,the impact toughness of the steel is increased by more than one time,compared with no addition of RE-modifier.

BEHAVIOUR OF Ti IN AS-CAST MEDIUM MANGANESE AUSTENITIC STEEL

The majority of Ti is found to be preferentially precipitated in the form of TiC from medium manganese steel melt.The TiC may contribute to the heterogeneous nuclei of fine austenite crystallization,to the retardation of dislocation movement as well as to pile-up and proliferate the dislocations,thus,the matrix of the as-cast steel will be effectively strength- ened.It was also found that the TiC can be acted as the heterogeneous nuclei of the nodular eutectic carbide formation and caused the dispersion o fan abundance of the carbide in the interstices between austenite dendrite arms.

Hot workability of high manganese transformation induced plasticity steel

The hot deformation behavior and microstructure evolution of high manganese transformation induced plasticity steel(Fe - 20Mn - 3Si - 3Al) were investigated by using hot compression test in a temperature range from 800℃to 1 050℃and strain rate ranging from 0.01 s^(-1) to 5.0 s^(-1).The effects of temperature,strain rate,and true strain on the flow behavior and microstructures of high manganese transformation induced plasticity steel were discussed.The results show that the dynamic recrystallization occurs only at higher temperature and lower strain rate.Hot deformation behaviors of high manganese transformation induced plasticity steel were sensitive to temperature and strain rate.The apparent stress exponent and the apparent activation energy of the investigated steel were about 4.280 and 463.791 kJ/mol, respectively.The apparent activation energy of the high manganese transformation induced plasticity steel was approached to the austenitic stainless steel(400 -500 kJ/mol).The hot working equation is obtained. Hot deformation peak stress increased with increasing of the value of lnZ.Peak stress and InZ exhibits a linear variation,the linear correlation coefficient was 0.988 9.The results show that the dynamic recrystallization was prone to occur when lnZ≤43.842 26 and Z≤1.098×10^(19),and better hot deformation properties would be obtained under this condition.

Hot deformation behavior and hot-metal-gas-forming process of V micro-alloyed high manganese steel

The hot deformation behavior of a newly designed V micro-alloyed high manganese steel(HMnS)was investigated in order to guide the development of the hot-metal-gas-forming process.Single-pass hot compression experiments were conducted in the temperature range of 950–1100°C and the strain rate range of 0.05–10 s^(−1),and the stress–strain curves and the corresponding softening mechanism of the V micro-alloyed HMnS were analyzed.Results show that two types of stress–strain curves,representing the work hardening(WH)-dynamic recovery(DRV)-dynamic recrystallization(DRX)mechanism and the WH–DRV mechanism,respectively,occur during the deformation process.Moreover,the WH–DRV–DRX mechanism gradually transforms into the WH–DRV mechanism with the increasing strain rate and decreasing deformation temperature.Two types of constitutive models considering the softening mechanism difference were established and verified by additional hot-deformation experiments.Hot processing map of the HMnS was established and correlated well with the microstructure evolution result.Based on the constitutive models and processing map,the optimal processing parameter range and flow stress of HMnS for the hot-metal-gas-forming were determined.

As-cast Medium Mn Steel with Nodular Carbide Modified by Y-base Heavy RE Compound

1.IntroductionMedium Mn steel was developed be-cause the wear resistance of Hadfield steel(Mn13)is poor under low or medium im-pact and extrusion abrasion[1-4].In theforegoing investigations[2-4]we found thatwith the increase of C content,theneedle-like and network carbide in mediumMn steel increased(as shown in Fig.1(a)and(c)).Although its wear resistance was largelyimproved,its impact toughness was greatlydecreased.In order to increase toughness,along-term high temperature heat-treatmentwas needed.But the treatment caused cracks

激光送丝熔覆高锰钢涂层的显微组织及超声滚压硬化机理

为了维持高锰钢部件优异的形变硬化能力,提出了高锰钢涂层的激光送丝熔覆技术。使用激光送丝熔覆技术在Mn13钢板上制备了高锰钢涂层,并通过超声滚压技术对熔覆层表面进行形变硬化处理。分析了超声滚压前后高锰钢熔覆层的显微组织、相组成和力学性能,揭示了高锰钢熔覆层的超声滚压硬化机理。研究结果表明,激光送丝熔覆高锰钢涂层的显微组织为枝晶结构,且在枝晶间存在Mn、C元素的成分偏析;超声滚压过程中未出现相变,超声滚压后涂层的硬度、耐磨性均大幅提高;初始高锰钢涂层内部存在的C、Mn的枝晶偏析、位错和孪晶在超声滚压过程中严重阻碍了位错的运动,从而增大了位错的密度;由于高锰钢的孪晶诱导塑性变形效应,超声滚压后涂层内部会产生大量的形变孪晶,形变孪晶之间的相互作用进一步增强了高锰钢熔覆层的形变硬化能力。激光送丝熔覆为大型高锰钢部件表面的高性能修复提供了技术基础。

固溶处理对新型全奥氏体高锰低温钢微观组织、力学性能及摩擦性能的影响

针对新型奥氏体高锰低温钢在LNG (Liquefied natural gas)储罐应用中的磨损问题,本文中研究了不同固溶处理温度对微观组织、力学性能和耐磨性能影响以及三者之间的关联性.将25Mn高锰钢分别在950、1 000、1 050以及1 100℃下固溶处理0.5 h,并采用光学显微镜、白光干涉仪、扫描电子显微镜及能谱仪对试样的微观组织、磨损轮廓和磨痕形貌进行了表征.结果表明:随着固溶处理温度的升高,高锰钢的表面硬度逐渐下降,1 100℃固溶处理后钢材硬度降到最低,约为261 HV.另外,钢材的抗拉强度随固溶温度升高先增大后减小,其中在1 000℃下展现出最优的抗拉强度、屈服强度及应变硬化速率.在摩擦性能测试结果中可以看出,高锰钢表面平均摩擦系数随着固溶处理温度先增大后减小再增大,在1 000℃时因发生氧化摩擦而降到最低,约为0.39,磨损率为0.49‰,表现了最优的耐磨性能.这主要是由于1 000℃热处理后的高锰钢磨痕表面密布颗粒均匀的碳化物,导致磨损后的硬度增大近50.6%,磨损机理从颗粒磨损与疲劳磨损结合转变为黏着磨损为主,颗粒磨损为辅.

高锰奥氏体低温钢发展现状、成分设计及热处理焊接工艺分析

以价格低廉的Mn替代价格较为昂贵的Ni,研发新型无Ni低温钢,已成为液化天然气(LNG)储罐用钢当前研究的新热点。本文依次介绍低温钢的概念和特点,以及高锰奥氏体低温钢国内外的发展现状,并详细列举了国家与团体标准中关于高锰奥氏体低温钢成分及性能的要求。综合分析不同元素对高锰奥氏体低温钢力学性能的影响,表明Fe-24Mn-0.45C-3Cr-0.5Cu系高锰奥氏体低温钢综合性能优异,可作为高锰奥氏体低温钢成分体系优化设计参考依据。研究表明,适当热处理可有效提升高锰钢低温韧性,而采用保护金属电弧焊后的焊缝低温韧性要优于埋弧焊,尽管两者屈服强度和抗拉强度无较大差别。

轻质耐磨高锰钢的研究进展

在“碳达峰”、“碳中和”成为全社会共识的背景下,轻质耐磨高锰钢因具有良好的强韧性、耐磨性以及较低的密度在冶金、矿山等行业中具有广阔应用前景。本文综述了轻质耐磨高锰钢的成分轻量化设计进展,以及基体组织、析出相以及表面改性对其耐磨性能影响,并展望了轻质耐磨高锰钢未来的发展趋势,以期为高锰钢轻量化及耐磨性能的协同提升设计提供参考。

疏浚用Q235钢和高锰钢冲刷腐蚀机理研究

目的对比传统疏浚用Q235钢和新型高锰奥氏体钢的冲刷腐蚀行为,分析2种钢冲刷腐蚀耦合损伤机理。方法利用射流喷射装置分别对Q235钢和高锰钢的纯磨损和冲刷腐蚀行为进行研究,采用电化学阻抗和质量损失测量方法对冲刷腐蚀耦合分量进行解耦,最后结合形貌表征分析冲刷腐蚀耦合损伤机理。结果纯磨损结果显示,在高流速沙砾冲击下,Q235钢和高锰钢都有较高的损失,Q235钢的纯磨损速率是高锰钢的2倍。冲刷腐蚀结果显示,Q235钢冲刷腐蚀总损失速率大于高锰钢的2倍,2种钢的冲刷腐蚀损失中磨损都占据了主导地位,Q235钢腐蚀加速磨损速率占据总损失速率的25.9%,大于高锰钢所占比例18.3%。结论通过对比分析2种钢宏观和微观损伤形貌,发现虽然高锰钢的硬度远高于Q235钢,但其变形能力同样很高,这使得高锰钢拥有比Q235钢更优异的抗磨性能。此外,Cr和Al元素的添加也进一步提升了高锰钢的抗腐蚀性能,最终使得高锰钢的抗冲蚀性能也远优于Q235钢。

混合稀土La、Ce对铸造高锰钢组织及夹杂物变性的影响

采用微量稀土La-Ce微合金化对高锰铸钢进行变质处理,借助金相显微镜、扫描电镜、能谱仪、冲击试验机、显微硬度计等检测手段,研究了La-Ce混合稀土对铸造高锰钢显微组织、夹杂物和力学性能影响。结果表明:微量的稀土La-Ce使高锰钢铸态组织柱状晶区缩短,等轴晶区扩大,二次枝晶间距减小,晶界碳化物细化;同时钢中夹杂物变性,由原来多边形的Ti N、Al_(2)O_(3)与Mn S复合夹杂转变为椭球状或球状的含稀土复合夹杂。稀土La-Ce改善了铸态高锰钢的冲击韧性及显微硬度,在0℃、-20℃、-40℃试验温度下横向冲击功分别提升32.3%、67.5%,170.0%,低温韧性提升更加显著;显微硬度HV10由221提升至238。

高锰钢表面耐磨蚀镀层研究

研究了不同化学镀工艺对高锰钢镀层组织和性能的影响。得出化学镀Ni-P的最佳参数为:NiSO_(4)·6H_(2)O质量浓度30 g/L;NaH_(2)PO_(2)·H_(2)O质量浓度35 g/L;pH值4.7。非晶态Ni-P镀层致密,厚度约25μm。镀层硬度由330 HV提高到600 HV以上,磨损体积减少。镀层的腐蚀电流密度从基体的8.51 mA/cm^(2)降低到1.82 mA/cm^(2)。镀层明显提高了高锰钢基体的表面硬度、耐磨性能和耐腐蚀性能。

TiN纳米陶瓷对ZGMn13微观组织和力学性能影响

为细化ZGMn13的组织,并提升其使用效果。采用TiN纳米陶瓷作为添加剂,以ZGMn13为基体材料,采用吹氩法制备了添加TiN纳米陶瓷的ZGMn13试样,并对试样进行了固溶处理;使用扫描电子显微镜观察了TiN纳米陶瓷对ZGMn13试样微观组织的影响;使用布氏硬度、冲击和磨粒磨损等试验设备,对试样的力学性能、摩擦磨损性能进行测试与研究。结果表明:通过吹氩法加入的TiN纳米陶瓷对ZGMn13的晶粒起到了明显的细化作用,同时组织中的连续网状碳化物也被明显地分散和隔断。添加TiN纳米陶瓷的ZGMn13试样的冲击吸收能量和硬度均有所提升。在试验条件下,添加TiN纳米陶瓷的ZGMn13试样的磨损量降低21.1%,耐磨性明显提高,摩擦磨损性能得到改善。

高锰钢辙叉淬火冷却过程模拟及淬火设备优化

高锰钢导热性能较差,导致辙叉在淬火时心部冷却速度较慢,容易在心部产生超标碳化物。通过热模拟试验和有限元数值模拟分析了高锰钢冷却过程中的显微组织和温度变化情况。热模拟试验结果表明:随着冷却速度增加,高锰钢析出碳化物逐渐减少,在5℃/s冷却速度下,析出碳化物级别为X2级。根据有限元模拟结果改进了冷却设备,使改进后的高锰钢心部冷却速度达到5℃/s,心部析出碳化物级别由X3级提升到X2级,力学性能得到提高,从而提高了高锰钢辙叉的产品质量。

热变形条件对高锰钢组织与性能的影响

高锰钢是一种常用的工程材料,其组织和性能与热变形条件密切相关。高锰钢连铸凝固过程中柱状晶发达、粗大且溶质显微偏析严重,具有显著的裂纹倾向和各向异性。本研究是针对高锰钢材料,在不同的压缩速率以及不同的温度下,采用热模拟试验、金相观察等方法探讨了其应力应变以及与金相组织的关系,找到最适合的热变形速率及温度,为保证高锰钢连铸坯生产顺利完成提供最佳热变形参数。对高锰钢材料来说,在不同的热变形条件下,可以明显改善高锰钢的晶粒大小,使得其组织与性能也有很大不同,试样的晶粒越粗大,相同应变下所需的应力越小,即压缩时变形越容易,当试样的晶粒越细小时,相同应变下所需的应力越大,也就是压缩时变形越困难。

磷、碳质量分数对粉末冶金高锰无磁钢组织与性能的影响

在高锰钢合金粉中添加不同质量分数Fe3P粉和石墨粉,采用压制烧结方法制备Fe–Mn–P–C无磁钢平衡块零件,研究了磷、碳含量(质量分数)对高锰无磁钢组织与性能的影响,并比较了Fe–Mn–P–C高锰钢与Fe–Mn–Cu–C高锰钢的性能。结果表明:添加Fe3P粉到高锰钢粉末中可以制备出组织均匀的无磁高锰钢。烧结件的密度和硬度随Fe3P添加量的增加而增大,当添加Fe3P质量分数超过2%之后,烧结件的密度基本保持不变;添加质量分数3%Fe3P的烧结件硬度最大,达到HRB 95左右。添加Fe3P质量分数小于1%的烧结件呈现无磁特性,添加Fe3P质量分数为2%时,烧结件呈现弱磁特性,添加Fe3P质量分数为3%时,烧结件呈现强磁特性。烧结件的密度和硬度随着石墨添加量的增加而增大,添加质量分数0.30%石墨时,烧结件的密度超过7.30 g·cm^(-3);石墨添加量小于0.30%时,烧结件呈现无磁特性;石墨添加量为0.60%时,烧结件呈现弱磁特性;石墨添加量超过0.75%时,烧结件呈现强磁特性。与Fe–Mn–Cu–C高锰钢相比,Fe–Mn–P–C高锰钢的密度相对较低,硬度和磁性与Fe–Mn–Cu–C高锰钢相当,但力学性能均优于Fe–Mn–Cu–C高锰钢。