| 详细介绍：
40crnimo棒料-40crnimoA价格//江苏40crnimo棒料-40crnimoA价格
苏州倍徕斯特殊钢事业部主要加工销售进口国产宝钢、东北特钢(抚顺特钢)、长钢、首钢、马钢、沙钢、杭钢、南钢,以及进口钢厂德国蒂森克虏伯钢铁、韩国浦项钢铁、德国撒斯特、日本新日制铁、美国钢铁、日本大同/日立、美国芬可乐、奥地利百禄、瑞典一胜百等各大著名钢厂的优质钢材,长期大量供应现货：
碳素结构钢Q235、Q345(A/B/C/D),SS300,S185等;
优质碳素结构钢65Mn,C10E,等;低合金高强度结构钢Q295,S690Q,550,等;
合金结构钢cr、mn、crmo、crmn、crni、crnimo、crmov、crmnmo、crmnsi、crnimov等系列合金钢：20cr~40cr、12~15crmo、20crmo、30crmo、35crmo、40~42crmo，42crmo4、20crmo4、4140、4118、4135、SCM415、SCM420、SCM430、SCM435、SCM440、12crmov、12cr1mov、35crmov、25cr2mov、25cr2mo1v、38crmoal、21crmov5-7、31crmov9、SACM645、41cralmo7、15crmn、20crmn、16mncr5、20mncr5、20crmnti、30crmnsi、35crmnsi、20crmnmo、40crmnmo、30crmnti、20crni、40crni、45~50crni、12crni2、12crni3、14nicr14、14nicr10、SNC415、SNC815、20crni3、30crni3、SNC631、37crni3、SNC836、15nicr13、12cr2ni4、20cr2ni4A、3316、3325、8640、4720、14nicr18、20crni2mo、sae4320、SNCM420、SNCM220、20crnimo、SAE8620H、aisi4340、SNCM439、40crni2mo、40crnimo、36crnimo4、34crnimo6、36crnimo16、40crnimo6、45crnimov、18cr2ni4wA、25cr2ni4wA、SAE8720等
易切削钢Y12、Y12Pb、Y15、Y15Pb、12L14、1215，9smn28、9smn28K、11smn30、Y40mn、Y20,等;
弹簧钢65Mn,60si2mn、60si2cr、SUP7SUP2,SUP10,6150等;
轴承钢Gcr15、G20crnimo、Gcr18、Gcr18mo、100Cr6,52100,9Cr18Mo等;
合金工具钢9SiCr,3cr2w8v、SKD11,SKD61、4crw2si、5crw2si、6crw2si、9cr2mo、9cr2、cr12、
cr12mov、5crnimo、90sicr5、3cr2mo、3cr2nimo、H13、SKD5、5crmnmo等;
碳素工具钢SM55,S45C,T7A、T8A、T8Mn，T10A,SM45,SM48等;
高速工具钢6542,W18cr4v、YXR3、YXM1、ASP2023、T4,SKH2,T15等。
40CrNiMo钢齿轮轴断裂原因分析
摘要：通过化学成分分析、力学性能测试、光学显微镜分析、扫描电镜和X射线能谱仪，对40CrNiMo钢齿轮轴断裂原因进行分析。失效分析结果表明，齿轮轴断裂为疲劳断裂，调质热处理不当及机加工缺陷是齿轮轴断裂的主要原因。关键词：40CrNiMo钢齿轮轴；失效分析；疲劳断裂；中图分类号：TG162.71 文献标识码：A
前言 某企业齿轮轴在使用较短时间后发生突然断裂，该轴是齿轮轴，断裂位置为齿轮轴大小直径的台阶处。在断裂过程中，齿轮轴一直在转动，所以断面被严重磨损和污染，接受样品时表面已经锈蚀，如图1所示。该轴的材质为40CrNiMo
钢，热处理状态为调质处理。
2理化检验 2.1化学成分 对断裂齿轮轴取样进行化学成分分析，检测结果表明，该轴的化学成分符合GB/T3077-1999标准中的对40CrNiMo钢的技术要求，如表1所示。说明轴的材质符合规定。 表140CrNiMo钢齿轮轴的化学成分（wt%）
Table
1Chemicalcompositionof40CrNiMosteelgearshaft（wt%）
项目 C Si Mn Mo P S Cu Cr Ni
实测值0.41 0.24 0.62 0.18 0.018 0.0048 0.20 0.71 1.36
标准值 0.37-0.44 0.17-0.37 0.50-0.80 0.15-0.25 ≤0.025 ≤0.025 ≤0.25 0.60-0.90 1.25-1.65
40NiCrMo钢是典型的调质钢，因其回火索氏体组织具有良好的强度、硬度、塑性、韧性而广泛用于轴类零件。断裂齿轮轴的化学成分符合标准GB/T3077-1999的要求，低倍组织观察未发现明显的中心疏松、一般疏松、偏析、一般点状偏析、皮下气泡、晶间裂纹，夹杂物评定结果合格。硬度检测结果表明，试样的表层硬度低于内部。齿轮轴内部碳含量高，外表面碳含量低，致使硬度值中心高、表面低。标准要求该轴的硬度小于269，而检测的几个点平均后的硬度值为282，高于标准要求。硬度偏高的原因可能是调质处理的回火温度偏低或保温之间过短。拉伸检测结果表明，齿轮轴的抗拉强度、屈服强度低于标准要求，原因可能是淬火过程中，没有得到尽可能多的马氏体组织。断面收缩率和冲击吸收能量偏小表明材料的塑性、韧性较差。 综上，在拉伸、硬度和冲击等性能的结果中，只有断后伸长率一项是合格的。由于该轴材质符合标准，力学性能不合格主要是由热处理不当引起。齿轮轴断面有裂纹源区、疲劳裂纹扩展区和瞬断区3个明显区域，属于典型的疲劳断裂。瞬断区约占断裂面60%，较大的瞬断区说明轴在服役中承受较大的拉应力。机加工浅槽台阶处的不规则的机加工缺陷则容易产生应力集中，触发早期裂纹。
Fracture analysis of 40CrNiMo steel gear shaft
Abstract: by chemical composition analysis, mechanical property test, optical microscope analysis, scanning electron microscope and X ray energy spectrometer, the causes of the fracture of 40CrNiMo steel were analyzed. Failure analysis shows that the fracture of the gear shaft is fatigue fracture, and the improper quenching and tempering heat treatment is the main cause of the fracture of the gear shaft. Key words: 40CrNiMo steel gear wheel axle; failure analysis; fatigue fracture; TG162.71
The gear shaft of the enterprise is suddenly broken after a short period of time, which is the gear shaft and the position of the fracture position is the diameter of the gear shaft. In the course of the fracture, the gear shaft is rotating, so the cross section is badly worn and polluted, and the surface of the sample has been corroded, as shown in Figure 1. The material of the shaft is 40CrNiMo
Steel, heat treatment state for conditioning treatment.
Chemical composition analysis of the chemical composition of the fractured gear shaft was carried out in 2 chemical test 2.1 chemical components. The results show that the chemical composition of the shaft is in accordance with the technical requirements of the 40CrNiMo standard, as shown in Table 1. The material of the shaft is in accordance with the regulations. Table 140CrNiMo chemical composition (wt%) of the steel tooth wheel axle
Table
1Chemicalcompositionof40CrNiMosteelgearshaft (wt%)
Item Si Mn Mo P S Cu Cr Ni C
Measured value 0.24 0.62 0.18 0.018 0.0048 0.71 1.36 0.20
The standard value of 0.37-0.44 0.17-0.37 0.50-0.80 0.15-0.25 = 0.025 0.60-0.90 1.25-1.65 = 0.025 = 0.25
40NiCrMo steel is a typical quenched and tempered steel, because of its high strength, hardness, plasticity, toughness and widely used in the shaft parts. The chemical composition of the fractured gear shaft meets the requirements of the standard GB/T3077-1999, and the low magnification observation has not found obvious central porosity, general porosity, segregation, general segregation, subcutaneous bubble, intergranular crack, inclusion assessment results are qualified. Hardness test results show that the surface hardness of the specimen is lower than that of the sample. The internal carbon content of the gear shaft is high, the external surface carbon content is low, resulting in the high hardness value center, the surface is low. The hardness of the shaft is less than 269, and the average hardness of the shaft is 282, which is higher than the standard. The reason of the high hardness of the high temperature and low temperature or heat preservation is the reason of the high hardness. Tensile test results show that the tensile strength and yield strength of the gear shaft are lower than the standard. The reason may be that the quenching process is not as much as possible. Section shrinkage ratio and impact energy of the impact of the small to show that the material is plastic, toughness is poor. In summary, the tensile, hardness and impact properties of the results, only the elongation is a qualified. As the shaft material is in conformity with the standard, the mechanical properties of the material are mainly caused by improper heat treatment. There are 3 distinct regions of the crack source area, the fatigue crack propagation zone and the transient zone in the gear shaft section, which are typical fatigue fracture. The transient zone is about 60% of the fracture surface, and the larger the stress of the shaft is in the service. The machining of the irregular machine with the shallow slot of the machine is easy to produce the stress concentration, and the early crack is triggered.
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