S45500冷轧薄板脆性问题探讨

本文通过S45500板材冷轧中出现脆性开裂现象的探讨，认识到S45500板材易产生氢脆，找到解决氢脆的办法。     

鞍钢重轨钢氢脆机制的研究

利用不同形变温度同速度,以及不同氢含量,我们研究了鞍钢产AP_1重轨钢的可逆氢脆机制。初步认为可逆氢脆的产生只有在一定形变温度,一定形变速度下位错的运动能成为运输氢原子的有效工具时,将足够数量的氢原子运到试样中的力学不稳定区后,AP_1重轨钢中此不稳定区可能是晶界,也可能是相界,并当此区中氢的浓度达到产生沉淀时便出现氢脆裂纹等,最后导致氢脆断裂。根据本文实验结果指出,只要拉伸应变率等于或小于2×10~(-5)/秒,AP_1重轨钢就会出现可逆氢脆,氢脆的敏感温度范围约在50℃到100℃之间。     

溶解氧变化对阴极极化下10Ni5CrMo钢氢脆敏感性的影响

摘要：为研究溶解氧质量浓度对10Ni5CrMo钢在阴极极化条件下氢脆敏感性影响规律，对10Ni5CrMo钢进行了阴极极化下的电化学交流阻抗谱测试﹑并采用慢应变速率拉伸实验和断口分析方法研究了海水中溶解氧质量浓度变化和不同阴极极化下10Ni5CrMo钢的氢脆敏感性。结果表明：溶解氧质量浓度变化对10Ni5CrMo钢强度几乎没有影响；同一溶解氧质量浓度下，随极化电位负移，断裂时间、伸长率、断面收缩率明显降低，氢脆系数增加，氢脆敏感性显著提高，极化电位达到-1000mV时，氢脆系数已超过安全区允许的最高值25%，进入危险区；同一极化电位下，随着海水中溶解氧质量浓度减少，材料塑性变差，断裂时间、伸长率和断面收缩率不断降低，氢脆系数增加，氢脆敏感性提高。     

铜冷却壁氢脆破坏现象的试验

 铜材氢脆现象是造成高炉铜冷却壁损坏的可能原因之一,但目前并未得到试验证实。模拟高炉工作环境对铜冷却壁材质进行了渗氢保温处理,在实验室条件下重现了高炉铜冷却壁氢脆现象,并采用金相显微观察、扫描电镜观察、氢氧质量分数检测及显微硬度测试等方法对铜冷却壁基体材质的微观形貌、元素质量分数及宏观使用性能等进行了表征。试验结果表明,在铜冷却壁异常工作条件下,将有可能产生铜材氢脆破坏作用;氢脆现象发生后,铜冷却壁内部将产生大量沿晶界分布的孔洞缺陷乃至晶界裂纹,且铜冷却壁宏观使用性能将出现显著下降;在炼铁生产中应严格控制铜冷却壁使用制度,防止氢脆现象发生以延长其寿命,保证高炉安全、稳定生产。     

固溶温度对2205双相不锈钢氢脆敏感性的影响

采用光学显微镜、慢应变速率拉伸、扫描电镜研究了2205双相不锈钢固溶温度与氢脆敏感性的关系。结果表明:随着固溶温度的升高,2205双相不锈钢中铁素体含量升高,奥氏体含量降低。奥氏体含量为48.8%时,2205双相不锈钢具有最低的氢脆敏感性,随着铁素体含量的上升,其氢脆敏感性逐渐升高。二次裂纹的产生和发展过程表明2205双相不锈钢氢脆敏感性是由奥氏体相的含量和晶粒尺寸所决定的。     

钢中的白点的检验

提出了检验白点时应区分不可逆氢脆白点和可逆氢脆白点，讨论了不可逆氮脆白点和发裂的关系，对检验白蹼的各种方法进行了评论。     

金属间化合物TiAl的氢脆本质

根据固体与分子经验电子理论分析计算了ＴｉＡｌ及含氢各相的价电子结构与解理能。结果表明，ＴｉＡｌ的氢脆是由于固溶氢减弱了含氢ＴｉＡｌ晶胞主干键并降低了解理能引起的。同时解释了有关ＴｉＡｌ氢脆的一些尚有矛盾的实验结果，并提出了一些解决其氢脆的实际方法。     

高强度钢氢脆机理研究进展

介绍了高强度钢氢脆机理的研究进展,并对各个机理的优缺点进行讨论,简述了影响合金氢脆的因素,同时着重分析几种钢的抗氢脆性能,并提出若干关于如何预防高强度钢氢脆的建议。     

轻型面包车车身开裂原因分析

以18台轻型面包车车身开裂为事实依据，通过对车身钢板的成分、组织、工艺进行分析检验，结果表明氢脆和应力腐蚀是造成车身开裂的原因。对车身产生应力腐蚀的条件进行了分析，提出了预防车身开裂的措施和工艺改进方法。     

Mn含量对超细晶C-Mn钢显微组织和力学性能的影响

石油压力容器在焊后热处理（PWHT）时存在一些热损失问题，诸如奥氏体不锈钢堆焊中σ相变和2．25Cr-1Mo钢的基本金属和堆焊界面问的碳化物析出等。另外，在诸如高温和高压氢气环境等工作状态发生氢脆。日本制钢所茅野林造等人。通过缺口拉伸试验对压力容器钢中的热脆和氢脆程度进行了测定。通过提高PWHT时的回火参数来降低抗拉强度和断裂延性。用光学显微镜观察拉伸试验试样横截面以检验PWHT后覆盖焊缝中的σ相变，通过对试样的显微组织和断口组织的观察来检验界面处的碳化物析出和氢脆。已经证实因为氢脆导致界面处碳化物层附近堆焊中裂纹穿过奥氏体晶界扩散。     

硅系耐热球铁的脆性研究

试验结果表明,铸态硅系耐热球铁固溶了一定数量的氢,它随硅原子溶入α-Fe而自发溶入,并在某些晶面形成偏析、导致氢脆。硅脆性与氢脆性的交互作用是硅系耐热球铁脆裂的实质。脆性裂纹多发生于石墨球／金属基体界面,这里也有氢的富集。     

35CrMo合金钢芯轴断裂失效分析

35Cr Mo合金钢芯轴在使用过程中突然断裂,对其化学成分、力学性能、显微组织、非金属夹杂、断口形貌等进行检测分析。结果表明,35Cr Mo芯轴的断裂以脆性断裂为主,主要是由于钢中的氢含量超标,在芯轴中心部位形成了大量白点,导致材料塑性显著下降,脆性急剧增加,从而引起了断裂。     

Internal hydrogen supersaturation produced by dislocation transport

A quantitative model is presented for the generation of internal supersaturations of hydrogen by kinetic rather than thermodynamic means. The maximum brittleness and slow strain rate limit is treated. The process invoked assumes hydrogen transport to deposition sites by dislocation drag, and reemission of the hydrogen by diffusion. The kinetic supersaturation is calculated from a balance between hydrogen arrival and departure rates, for internal and external hydrogen sources, and for smooth section and crack geometries. When applied to ferritic and austenitic steels, the model predicts that the kinetic supersaturations are extremely small in all realistic situations.     

Internal hydrogen supersaturation produced by dislocation transport

A quantitative model is presented for the generation of internal supersaturations of hydrogen by kinetic rather than thermodynamic means. The maximum brittleness and slow strain rate limit is treated. The process invoked assumes hydrogen transport to deposition sites by dislocation drag, and reemission of the hydrogen by diffusion. The kinetic supersaturation is calculated from a balance between hydrogen arrival and departure rates, for internal and external hydrogen sources, and for smooth section and crack geometries. When applied to ferritic and austenitic steels, the model predicts that the kinetic supersaturations are extremely small in all realistic situations.     

Edge defect analysis of high-strength corrosion-resistant steel

In this study,a 600 MPa hot-rolled corrosion-resistant steel plate produced by a specific company is investigated. Edge jagged defects and edge surface defects generated on both sides of the strip during production are characterized and analyzed. The results indicate that the distribution of reoxidation granules is located underneath the surface peel and that copper-containing granules diffuse along austenite grain boundaries. This phenomenon combined with the chemical composition and production parameters of a strip indicate that copper brittleness leads to edge jagged defects. However,the surface defects should be attributed to inherent defects on the surface of the strip. Measures that prevent surface oxidation and copper segregation at grain boundaries would likely eliminate these two types of edge defects.     

中温临氢钢12Cr2Mo1R回火脆性研究

对正火回火状态的中温临氢钢12Cr2Mo1R进行模拟最小程度焊后热处理试验,采用阶梯冷却加速脆化法,进行了回火脆化处理,并对12Cr2Mo1R钢的回火脆化敏感性进行了研究。试验研究结果表明:12Cr2Mo1R具有良好的抗回火脆化性能,该钢在阶梯冷却试验前后的组织形貌无明显变化。     

Effect of precipitated phase on resistance to hydrogen embrittlement of high Co- Cr- Mo- Ni bearing gear steel

High Co- Cr- Mo- Ni bearing gear steel was used as the test material, and hydrogen induced fracture process of the test steel was studied by TDS test, slow strain rate drawing and micro analysis. The results show that the high plasticity of the test steel is obviously decreased. Most of the hydrogen in the test steel is diffusible hydrogen, which is controlled by the weaker hydrogen trap. By comparing the grain size, the size of the strip, the number of residues, the dislocation density and the precipitation of the two kinds of test steels, the main influencing factors of the anti- hydrogen brittleness of test steel are the carbon density and distribution, and dispersed fine carbides are more conducive to improve hydrogen embrittlement resistance. The critical hydrogen concentration is obtained and the critical hydrogen concentration is deduced, which provides a reference for the high reliability and safe service of the components.     

注氢硅中微结构缺陷的TEM观察

通过透射电子显微镜观察到注氢硅片中存在损伤带，损伤带的位置和注人氢的分布几乎一致，推断损伤带是由于氢的注入引起的。损伤带内主要以平行于正表面的{111}面状缺陷为主，另外还有斜交于正表面的{111}面状缺陷以及{100}面状缺陷，这是由于氢朝能量低的位置的迁移聚集而形成的。在损伤带的中间还可见到晶格紊乱团块和空洞，这是由于损伤带中间存在高浓度的氢和高密度的面状缺陷面导致形成的。     

42CrMo4钢板冷弯曲中断裂原因分析

利用金相显微镜和扫描电镜等分析方法,对42CrMo4钢板冷弯曲中断裂原因进行分析。结果表明,断裂钢板内部存在严重的组织缺陷,钢板局部区域存在马氏体组织、孔洞、严重的组织偏析和较大尺寸的钛颗粒夹杂,这些因素导致该区域组织应力和脆性较大,成为钢板内部的裂纹源,在弯曲成形过程中的拉应力作用下产生裂纹,并不断扩展导致钢板断裂。