两种抗氢钢临氢500h的抗氢性能分析

对2．25Cr-1Mo钢和3Cr-1Mo-0.25V钢在550℃、20MPa（氢分压16MPa）的条件下进行500h的充氢处理,然后测试其拉伸性能,在光学显微镜下观察金相组织和脱碳层,在电子显微镜下观察断口形貌和甲烷气炮,结果表明,两种钢都具有良好的抗氢蚀性能,而且含钢的抗氢性能更好。     

工业用钢2.25Cr-1Mo与2.25Cr-1Mo-0.25V的性能对比分析

主要从化学组成、力学性能及焊接性能等方面阐述工业用钢2．25Cr-1Mo与2．25Cr-1Mo-0．25V的性能差异,通过分析．表明2.25Cr-1Mo-0．25V钢在一定的焊接条件下具有良好的焊接性,其抗回火脆化性能能力远优于2．25Cr-1Mo钢。     

2．25Cr-1Mo-0．25V钢加氢反应器开发与制造中的一些问题

由于对尺寸增大和高设计参数加氢反应器的需求，促使要制造更大、更重的高温钢加氢反应器。20世纪80年代开发了2．25Cr-1Mo-0．25V钢。钢中添加V后影响到焊接与热处理时的氢陷阱、氢扩散与应力松弛。制造规范需要进行调整，以防止焊接接头发生硬度高、韧性低以及持久强度低和开裂等问题。本文扼要介绍了以往2．25Cr-1Mo-0．25V钢容器制造过程中发生的一些问题及国外研究工作的进展，对国内需进行的工作提出了建议。     

2.25Cr-1Mo-0.25V钢焊缝扩散氢分布试验

阐述了焊后不同后热处理工艺时2. 25Cr-1Mo-0. 25V钢焊缝中扩散氢的分布数据测量,结果表明,焊后不同后热处理后,2. 25Cr-1Mo-0. 25V钢焊缝中距离盖面层以下15～20 mm扩散氢含量最高,且随着后热温度的提高、保温时间的加长,扩散氢含量呈下降趋势,为2. 25Cr-1Mo-0. 25V钢制容器焊后消氢的合理性提供参考。     

微量元素对2(1/4)Cr-1Mo钢与3Cr-1Mo钢性能影响的研究

近来日本川崎钢铁公司广泛地研究了各种微量元素含量对21/4Cr-1Mo与3Cr-1Mo钢的抗氢腐蚀、蠕变断裂应力、高温强度与再热裂纹倾向等性能的影响。试验证明,适当地选择微量合金元素含量并降低杂质元素可获得优异的钢的性能。经研究认为,适当调整21/4Cr-1Mo钢的成份,可使其各种性能均不低于3Cr-1Mo钢,但价格比3Cr-1Mo钢便宜。 1.试验用钢的成份与热处理     

2.25Cr-1Mo钢和FV520B钢的氢脆敏感性对比试验研究

通过电化学充氢和慢应变拉伸试验以及SEM断口形貌观察对2.25Cr-1Mo合金结构钢和FV520B马氏体沉淀硬化不锈钢的氢脆敏感性做出了评价。结果表明,在充氢环境中两种材料表现出了相似的抗氢脆性能,两种材质试样的断面收缩率与未充氢试样相比均呈现出相同的下降趋势;氢对缺口强度的影响也比较接近,2.25Cr-1Mo钢和FV520B钢充氢后的强度衰减率分别为9.2%和8.6%;SEM断口分析结果显示：两种材料充氢后的断口形貌均表现出了相似的韧窝状断裂特征,它们的破坏形式并没有因为充氢而发生改变。由此可见,两种材料的抗氢能力处于同一等级,具有成本优势的2.25Cr-1Mo合金结构钢可以和FV520B沉淀硬化不锈钢一样用于氢介质条件下运行的透平式压缩机中。     

2．25Cr-1Mo-0．25V纯净钢简体锻件的工艺与性能

为了制造千吨级煤液化反应容器，满足更高温度(482℃)和更高的强度等级(σ0．2≥415MPa)，减少筒体锻件的重量，在原采用的2．25Cr-1Mo钢的基础上，开发出了加V钢。针对煤液化装置(或大型热壁加氢反应器)用2．25Cr-1Mo-0．25V纯净钢筒体锻件的特点及理化性能要求，分析了冶炼、锻造、热处理等工序的难点，在进行大量的国内、外资料查寻以及材料和工艺试验的基础上，制定出并实施了制造工艺，经过筒体锻件的解剖及理化检验，证明所采用的工艺方法是非常有效的，完全满足煤液化装置用钢2．25Cr-1Mo-0．25V的质量要求。     

我国热作模具钢性能数据集（续Ⅱ）

(2 )　 5Cr Mn Mo Si V钢5Cr Mn Mo Si V钢是无镍多元合金化热锻模钢 ,它在 4Cr Mn Mo Si V钢的基础上增加碳的含量 ,和含有少量钒所以比 5Cr Ni Mo钢具有更好的淬透性和强韧性 ,在 40 0 mm× 40 0 mm截面上可以完全淬透。与5Cr Ni Mo钢相比热疲劳性能几乎相当 ,除可切削性和高温伸长率较低及锻造变形抗力较高外 ,其冲击韧性和断裂韧性、高温强度、抗回火稳定性、热磨损性和抗氧化能力都有较大的提高。如要获得同样硬度其回火温度比 5Cr Ni Mo钢约高 1 0 0°C。适宜制作大型复杂的重载锤锻模。但是此钢的热强性和耐磨性同样不如高…     

2．25Cr-1Mo-0．25V钢的硫化氢应力腐蚀试验研究

为了解2．25 Cr-1 Mo-0．25 V钢材料性能,利用慢应变速率法,在常温湿硫化氢环境下,给出了不同浓度硫化氢溶液对2．25Cr-1Mo-0．25V钢应力腐蚀的敏感性指数值;采用恒定位移法,将2．25Cr-1Mo-0．25V钢用线切割方法做成了楔形张开加载预裂纹试样,在确认了加载载荷和位移量后,在不同浓度的H2S溶液中,确定了2．25Cr-1Mo-0．25V钢应力腐蚀裂纹扩展速率和腐蚀临界应力强度因子。     

2.25Cr-1Mo-0.25V钢加氢反应器的研制

2.25Cr-1Mo-0.25V钢是当前设计温度454℃以上高压临氢设备首选用材，具有强度高、抗氢侵蚀能力强、抗氢脆性能显著、回火脆化倾向小、抗氢致剥离性能优良等特点。本文通过首台产品研制，介绍了2.25Cr-1Mo-0.25V钢锻焊结构热壁加氢反应器制造技术。     

高温长期运行Cr-Mo钢断裂性能微试样测试实验研究

开展采用小冲杆微试样试验技术评定材料断裂性能的研究.针对2.25Cr-1Mo钢(脆化态和脱脆态)及1.25Cr-0.5Mo钢,将小冲杆试验测试结果与常规冲击韧度及断裂韧度试验结果相关联,得到小冲杆试样变形过程中消耗的总变形能与常规夏比冲击功间的对应关系经验公式,以及小冲杆试样等效断裂应变与材料延性断裂韧度间的关联式,说明可以直接采用小冲杆试验结果估算材料的冲击及断裂韧度值,为无法取标准试样进行材料抗断裂性能测试场合提供了一种可行的间接测试技术.     

2．25 Cr－1 Mo和2．25 Cr－1 Mo－0．25 V钢加氢反应器材料和制造经验

介绍了ASME规范和API标准对2．25Cr－1Mo钢和2．25Cr－1Mo－0．25V钢材料和制造方面的规定,梳理总结了国内外专利商技术文件对2．25Cr－1Mo钢和2．25Cr－1Mo－0．25V钢焊材和母材在回火脆性、力学性能、再热裂纹等方面的要求。     

Mechanical behavior of erosion-corrosion scales on steels as characterized by single-particle impacts

Samples of 2.25Cr-1Mo (less than 0.5 Si) and 2.5Cr-0.55Mo-1.4Si steels were eroded-corroded at 450 and 650 °C using fluidized bed combustor bed particles at velocities of 10 and 20 m s⁻¹. The steel with higher silicon content showed significantly lower metal loss rates under all conditions.

The samples were subsequently subjected to single-particle impacts using spherical WC particles at velocities around 50 m s⁻. The impact response of the scales could be explained in terms of a combination of substrate hardness and scale morphology effects but could not be consistently related to the superior erosion-corrosion resistance of the steel with higher silicon content. All scales were composed of oxidation product and deposited bed material erodent. Samples eroded-corroded at 450 °C had denser, more mechanically stable scales which could be associated with the generally lower erosion-corrosion rates at this temperature. At 650 °C the scales were more loosely packed, especially at the lower erosion-corrosion velocity, which resulted in apparent ductility by permitting them to densify under impact. Scales were either segmented or continuous in appearance. Thick continuous scales maintained their integrity under the lower velocity conditions of the erosion-corrosion tests, thus leading to low metal losses, but spalled catastrophicaliy under the single impacts. Segmented scales spalled in smaller pieces under single impacts. It is proposed that the segmented scales would exhibit significant failure under low velocity conditions, thus providing less protection to the steels than continuous scales under similar conditions.     

Experimental study of grinding fluids for abrasive-belt grinding of stainless steel

A number of ferritic stainless steels with high corrosion resistance have recently been developed, but these steels are known to be difficult to grind in coated abrasive-belt grinding operations. In order to formulate or select an optimum oil-based grinding fluid with which such stainless steels can be successfully ground, an optimum base oil was first experimentally selected, and then additives were evaluated for their effect in improving abrasive-belt grinding performance. A paraffinic mineral oil having a certain viscosity was found to be suitable for the base oil. Chemical grinding oil additives were found markedly effective in improving the abrasive-belt grinding performance for both 19Cr-2Mo ferritic stainless steel and SUS 304 austenitic steel, with those containing sulphur or chlorine being superior to those containing phosphorus, fatty acid or alcohol. Among all the additives tested, chemically active oils, such as sulphurized mineral oil, exhibited the best performance. Effects of chlorinated paraffins on the grinding performance could be perceived but were not so great as those of sulphur-series additives. The addition of TCP (tricresyl phosphate) to the grinding oil containing sulphur reduced metal removal in the case of 18Cr-2Mo ferritic stainless steel (SUS 444). In the case of SUS 430 ferritic stainless steel, however, TCP increased metal removal for a comparatively low sulphur concentration, but, above an optimum concentration of 0.4 wt% S, metal removal was reduced by TCP addition. A comparison of sulphur-series additives added to a sulphurized paraffinic mineral oil showed that nonyl polysulphide was superior to any other additives for improving the grinding performance in 19Cr-2Mo steel (SUS 444) and SUS 430. Excess addition of sulphurized fatty oil to a grinding fluid lowered the cutting ability of abrasive grains.     

小冲杆试验评价材料的断裂韧度

为了评价材料断裂韧度，通过小冲杆试验对2．25Cr1Mo的回火脆态、脱脆态、焊缝区以及1．25Cr0．5Mo钢进行了试验研究，并对所得的小冲杆试验数据进行了分析。结果表明小冲杆等效断裂应变εe与小冲杆能量Esp之间存在重要的线性关系；同时发现断裂点的小冲杆能量值与材料的断裂韧度值线性相关。该方法为无法获取标准试样进行材料抗断裂性能评价场合提供了一种可行的测试技术。     

石化容器用2.25Cr-1Mo-0.25V钢的CMT电弧熔丝增材制造工艺及组织性能研究

为探索大型石化筒体根部止口的制造新工艺,采用新研发的2.25Cr-1Mo-0.25V合金丝材,使用CMT电弧熔丝增材制造技术首次堆积2.25Cr-1Mo-0.25V直壁墙,探索增材后的最佳热处理工艺,以改善沉积态显微组织与力学性能。实验发现：增材成形的直壁件内部微观组织主要为板条贝氏体、粒状贝氏体和部分马氏体,堆积方向组织差异明显,显微硬度浮动剧烈,拉伸强度远高于母材,但断裂延伸率较低。对增材后的直壁件施加“消氢处理+去应力处理”和“模拟最小焊后热处理”,发现后者能将其塑性提升至与母材相当。根据显微组织分析,经过“最小焊后热处理”,沉积态的板条贝氏体和部分马氏体可转变成均匀分布的粒状贝氏体,组织间的各向异性显著降低。实验证明,应用新研发的2.25Cr-1Mo-0.25V丝材在最佳的CMT电弧熔丝增材工艺参数下成形直壁件并结合“最小焊后热处理”能够最大程度地改善显微组织和力学性能,最终满足石化容器筒体根部止口的服役指标。相比浇铸-锻造成形止口的工艺,开发的CMT电弧熔丝增材新工艺有望大幅节约生产成本,提高制造效率。     

耐高温腐蚀材料制热高分罐制造技术

阐述了1．25Cr-0．5Mo—Si钢及相匹配的焊接材料的主要特点和设备结构，重点论述了设备的焊接工艺性试验、堆焊工艺、技术特点及过程质量控制要求。     

接管对接TIG自动焊工艺研究

针对加氢反应器制造中接管或弯管的对接焊缝,以1.25Cr-0.5Mo材料为例进行焊接试验,探究一种合理的自动TIG焊工艺。