Effect of Rare Earths on Tensile Behavior of Hot Roller Steel 60CrMnMo and Estimation of Roll′s Fatigue Life

The effect of rare earth(RE) on tensile behavior of hot roller steel 60CrMnMo was investigated at the temperature when roll served The roll′s fatigue at 500 ℃ was estimated The results show that elongation δ of hot roller steel 60CrMnMo can be increased by adding RE It is possible to estimate the fatigue life with tensile behavior of hot roller steel 60CrMnMo

Effect of Rare Earth Elements on Low Frequency Fatigue Cyclic Softening of Hot Rolled Steel 60CrMnMo at High Temperature

The effect of rare earth (RE) on cyclic softening of low frequency fatigue of the hot rolled steel 60CrMnMo at high temperature was investigated. The hardness of specimens before thermal fatigue test and being cycled 180 times from room temperature to 650℃ was compared. The results show that by adding a certain amount of RE in steel 60CrMnMo, the cyclic softening during low frequency fatigue test at high temperature can be restrained considerly. The carbide particles were refined during tempering treatment and the agglomeration and growth of carbide particles can be obstructed during thermal cycle.

Effect of Rare Earth Elements on Low Frequency Fatigue of Hot Rolled Steel 60CrMnMo at High Temperature

The effect of rare earth(RE) on low frequency high temperature fatigue strength of hot rolled steel 60CrMnMo was investigated. The results show that by adding a certain amount of RE in steel 60CrMnMo, its serviceable life during low frequency fatigue test at high temperature can be improved.The number of cycles for fracture was increased by 18.5%～28.8%. The number of large inclusion particleswas reduced and the composition of inclusions and their shape were changed as well. The strip distances on fatigue fracture surface were decreased. It is concluded that the optimum amount of RE addtion is about 0.05 wt%～0. 10 wt%.

Effect of Rare Earth Elements on Growth Dynamics of Austenite in 60CrMnMo Steel

The growth dynamics of austenite grains was investigated in 60CrMnMo steel with different RE elements. The results show that austenite grains of 60CrMnMo steel can be refined and their growth can be restrained by adding a certain amount of RE. From the experimental results, the values of n and Q were evaluated.

60CrMnMo钢热疲劳裂纹生成与长大及稀土的作用

采用金相和扫描电镜等手段对６０ＣｒＭｎＭｏ钢热疲劳裂纹的萌生和长大规律进行了分析，并考查了稀土在钢中的作用。结果表明：热疲劳裂纹萌生于钢中夹杂物处；热疲劳裂纹的生长，不仅是裂纹自身发展的结果，更主要的是裂纹的相互联接。钢中加入稀土后，可以变质钢中夹杂物。

稀土对60CrMnMo钢奥氏体长大动力学的影响

研究了不同稀土加入量对６０ＣｒＭｎＭｏ钢奥氏体晶粒长大动力学的影响。结果表明，６０ＣｒＭｎＭｏ钢中加入一定量的稀土，能细化奥氏体晶粒并抑制其长大。根据实验结果，对奥氏体晶界迁移激活能（Ｑ）进行了计算，计算表明随稀土加入量增加，Ｑ值亦增加。

稀土元素对60CrMnMo热轧辊用钢抗氧化性能的影响

研究了６０ＣｒＭｎＭｏ钢中氧化对热疲劳裂纹萌生和长大过程的作用，同时对不同稀土加入量的６０ＣｒＭｎＭｏ钢试样在不同温度、不同保温时间进行了氧化增重对比试验，并采用金相、电镜和Ｘ射线衍射方法进行了氧化皮形貌观察和晶体结构分析。结果表明：随着稀土加入量的增加，试样的氧化速度降低，氧化物颗粒细化，从而抑制了热疲劳裂纹处的氧化，提高了热疲劳寿命。

稀土对60CrMnMo热轧辊钢塑性的影响及低周疲劳寿命的估算

研究了稀土对６０ＣｒＭｎＭｏ热轧辊钢在其工作温度下塑性的影响，同时对其在５００℃时的低周疲劳寿命进行了估算。结果表明，稀土元素能提高６０ＣｒＭｎＭｏ的延伸率，采用拉伸性能估算疲劳寿命是可行的。

热处理对60CrMnMo轧辊钢微观组织与硬度的影响

研究了一次正火、二次正火和油淬三种热处理工艺对60Cr Mn Mo轧辊钢组织与性能的影响,并对一次正火、二次正火和油淬后的试样进行560℃、580℃和600℃回火处理。运用金相显微镜、硬度测试机等手段对不同工艺处理后的试样进行组织和性能检验分析。结果表明:不论是否进行回火,油淬后的60Cr Mn Mo轧辊钢试样硬度高于正火态试样。对于560℃、580℃和600℃回火处理,一次正火和油淬后的试样硬度值呈现下降趋势,而二次正火后的试样是呈现先上升后下降变化趋势。热处理后的60Cr Mn Mo轧辊钢金相组织各不相同,一次正火后的组织为贝氏体,二次正火后的组织为珠光体和铁素体,油淬后的组织为马氏体和碳化物。

Y_2O_3对WC-B_4C激光合金化层裂纹与耐磨性能的影响

目前,有关稀土氧化物粉末粒度大小及含量对激光陶瓷合金化层裂纹及耐磨性能影响的研究较少。以近纳米级Y2O3-WC-B4C粉末对60CrMnMo钢表面进行激光陶瓷合金化,以提高其耐磨性能。采用金相显微镜、扫描电镜、X射线衍射仪、显微硬度计、轮式磨耗试验机分析、考察了Y2O3含量对合金化层的组织、物相、硬度及耐磨性能的影响。结果表明:Y2O3使合金化层表面更加平整、光滑,表面裂纹减少、变细;合金化层硬度随着Y2O3含量增加而降低;合金化层物相主要有Fe-Cr,Cr23C6,B2W,B13C2等;随Y2O3含量增加,树枝晶减少,合金化层组织更均匀致密,磨损量先减小后增大;Y2O3含量为4%时,合金化层组织最细、耐磨性最好。

60CrMnMo钢轧辊堆焊修复及热处理工艺

在分析60CrMnMo钢轧辊堆焊修复和热处理工艺的基础上,研制了局部堆焊修复的焊接材料。选择Stellite multipass224药芯焊丝和HJ107焊剂作为整体轧辊堆焊材料,通过焊前预热、局部焊补、轧辊表面埋弧堆焊、焊后热处理等措施,成功修复了尺寸为1150mm的60CrMnMo钢轧辊。实践证明,经该工艺处理后轧辊使用寿命提高0.5倍。