焦炭塔用14Cr1MoR材料焊接工艺分析

近几年国内大型炼厂焦炭塔常用的材料为15CrMoR.2008年我公司制造了两台以14Cr1MoR珠光体耐热钢(Cr-Mo系低合金耐热钢)为主材的焦炭塔.本文就此钢种材料的焊接性能及工艺,作如下介绍.     

14Cr1MoR制压力容器制造的关键点控制

针对14Cr1MoR材料的性能特点,介绍了由该材料制造的设备的材料控制、焊接、热处理、无损检测等关键点。     

12Cr1MoVG厚壁管道合理的焊接工艺及热处理工艺

通过实践研究表明,12Cr1MoVG厚壁管道在低温环境下进行焊接时,容易有裂纹缺陷存在于焊缝处,针对这个问题,就需要结合管道材质的焊接性能,对焊接工艺进行合理的选择。在生产当中,12Cr1MoVG厚壁管道冲击韧性较低,针对这个问题,就需要控制正火冷却速度,本文提出了水冷结合空冷的正火热处理工艺,希望可以提供一些有价值的参考意见。     

14Cr1MoR钢焊接工艺性研究及应用实践

14Cr1MoR低合金耐热钢焊接性较差,具有一定程度的淬硬性以及氢致裂纹和再热裂纹倾向。通过焊接工艺性研究及应用实践,制定合理的焊接工艺,避免产生危及影响焊接接头本质安全的缺陷。设计合理的坡口型式,选择合适的焊接方法,匹配相应的焊接材料,选择适宜的预热温度和道间温度,避免焊接大线能量的输入。采取焊后消氢处理以及消除应力热处理等预防措施,使其焊接接头获得良好的综合力学性能。     

14Cr1MoR制临氢压力容器焊接工艺评定理化试验项目探讨

将14Cr1MoR制临氢压力容器技术条件中有关焊接工艺评定理化试验项目要求的内容,与国内外相关标准、规范进行了对比和分析,对其中的一些不合理之处给出了个人建议,为设计人员和焊接技术人员提供了有益的参考.     

12Cr1MoVG、15CrMo异种钢焊接工艺分析及厚壁管道合理的焊接工艺及热处理工艺

12Cr1Mo VG属于常见的珠光体耐热钢,15Cr Mo属于低合金珠光体耐热钢,这两种异种钢都具有很好的抗氧化性与热强性,但这两种钢在进行焊接时,都容易出现冷裂纹等缺陷。针对这一问题,主要对12Cr1Mo VG与15Cr Mo异种钢的焊接工艺进行了分析,对厚壁管道合理的焊接工艺与热处理工艺进行了优化研究。     

层间温度对12Cr2Mo1R低合金钢焊接冲击韧性的影响

对加氢精制反应器用12Cr2Mo1R低合金钢进行焊接工艺评定。分析了层间温度对12Cr2Mo1R钢材焊接后力学性能的影响,制定了合理的焊接工艺及工艺参数,为获得可靠的焊接接头提供基础。     

00Cr18Ni5Mo3Si2+Q235复合不锈钢板的焊接

复合不锈钢以其良好的使用性和经济性被广泛应用于炼油和石化装置防腐耐高温压力容器和管道中。分析了复合不锈钢板其中一种 0 0Cr1 8Ni5Mo3Si2 +Q2 35的焊接性能 ,进行了焊接工艺试验 ,制定了合理的焊接工艺措施 ,在实践中取得了良好的效果     

Q345R和OCr18Ni12Mo2Ti复合板的堆焊工艺

对碳钢表面堆焊不锈钢进行了介绍,论述了此类管板堆焊的施工工艺。在施工过程中,通过焊接顺序、焊接工装和层间温度控制等措施来控制堆焊时的焊接变形。     

发电机组汽轮机主蒸气线Cr5Mo钢管焊接出现的问题及处理方法

Cr5Mo钢管对接焊缝经焊后无终断热处理24h后进行RT100%检测,发现在高空焊接水平固定焊口4～6～8点位置全部是冷裂纹,通过对材料的化学成分及焊接过程控制分析从材料本身的淬硬倾向,预热温度和层间的控制未能达到工艺要求,是产生冷裂纹的主要原因。文章从预热保持层间温度的方法等方面详细介绍了返修工艺并取得了很好的效果。     

改性沸石对废水中Cu2+、Cr3+的去除作用研究

用Na OH碱熔-水热法处理得到的改性斜发沸石作为吸附交换剂,对模拟废水中以Cu2+、Cr3+为代表的重金属离子进行吸附处理。研究了不同吸附时间、投加量以及初始浓度条件下,改性斜发沸石对Cu2+、Cr3+的去除效果。实验结果表明:改性沸石与水样中Cu2+、Cr3+的质量比分别为18.75∶1、13.33∶1时,对Cu2+、Cr3+的去除率分别达88.0%、87.4%,且为快速吸附平衡过程。此外,用Na Cl溶液和Na Cl溶液加氨水对吸附Cu2+饱和的改性沸石进行再生实验,再生率较高,改性斜发沸石可以多次重复利用。     

A~2/O+BAF集成技术处理煤化工污水研究与应用

针对陕西黄陵煤化工有限责任公司焦化污水情况,在原有A2/O工艺的基础上,引进曝气生物滤池(BAF)工艺,组合成A2/O+BAF法。采用A2/O+BAF污水处理工艺,处理后的水质达到国家一级排放标准,对COD、氨氮、酚的去除率均达到了95%以上,且将处理后的废水用于熄焦,解决了焦化生产过程中产生的废水对环境造成污染的问题,从而使焦化生产用水得到循环利用,实现零排放。另外,剩余污泥用于掺混炼焦,解决了污泥的处理问题。     

Negative thermal expansion of (Al1/3Fe1/3Cr1/3)2(Mo1/2W1/2)3O12 (AFCMW) and low thermal expansion of AFCMW-(Co1/2Ni1/2)(Mo1/2W1/2)O4 with high entropy

A₂Mo₃O₁₂ (A-Al, Fe, Cr) have large negative thermal expansion (NTE) coefficients and structural stability but high phase-transition temperatures (PTTs). Herein, we prepared (Al_1/3Fe_1/3Cr_1/3)₂(Mo_1/2W_1/2)₃O₁₂ (AFCMW), and found it to have a low NTE coefficient and a low PTT. Furthermore, combination of AFCMW with (Co_1/2Ni_1/2)(Mo_1/2W_1/2)O₄ (CNMW) afforded an AFCMW–CNMW composite with a low thermal expansion (LTE). We determined that the PTT reductions in A₂Mo₃O₁₂ are largely due to the high-entropy effect resulting from the introduction of different ions into its A and M sites. Moreover, we found that the low LTE of the AFCMW–CNMW composite is attributable to the opposite thermal expansion behaviours of AFCMW and CNMW. We suggest that the suppressed thermal expansion during the phase transition process of the AFCMW–CNMW composite could be derived from the high-entropy effect resulting from its increased diversity of polyhedra, the influence of Co²⁺ and Ni²⁺ dopants, and CNMW-induced lattice distortion.     

Effect of Ni Substitution on the Structural,Magnetic, and Electronic Structure Properties of Gd0.4Tb0.6(Co1−xNix)2 Compounds

The comprehensive research of magnetic and electronic structure properties of the new class of Gd_0.4Tb_0.6(Co_1−xNi_x)₂ compounds, crystallizing in the cubic Laves phase (C15), is reported. The magnetic study was completed with electrical resistivity and electronic structure investigations. The analysis of Arrott plots supplemented by a study of temperature dependency of Landau coefficients revealed that all compounds undergo a magnetic phase transition of the second type. Based on magnetic isotherms, magnetic entropy change (ΔS_M) was determined for many values of the magnetic field change (μ₀H), which varied from 0.1 to 7 T. For each compound, the ΔS_M had a maximum around the Curie temperature. Both values of the |ΔS_M^max| and relative cooling power RCP parameters increased with increasing nickel content. It is shown that structural disorder upon Co/Ni substitution influences some magnetic parameters. The magnetic moment values of Co atoms determined from different methods are quantitatively consistent. From the M(T) dependency, the exchange integrals J_RR, J_RT, and J_TT between rare-earths (R) and transition metal (T) moments were evaluated within the mean-field theory (MFT) approach. The experimental study of the electronic structure performed with the use of the X-ray photoelectron spectroscopy (XPS) was completed by calculations using the full-potential linearized augmented plane waves (FP-LAPW) method based on the density functional theory (DFT). The calculations explained experimentally observed changes in the XPS valence band spectra upon the Ni/Co substitution.