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研究了热壁加氢设备用焊条的特征、熔敷金属的韧性、抗回火脆性及影响回火脆性的因素,通过严格筛选原材料,控制熔敷金属的杂质含量,采用优化设计的先进手段设计出了R407A热壁加氢设备的专用焊条,对R407A焊条进行了回火脆性试验和脆性转变温度等试验,焊条的各种性能完全达到了日本CMA-106N焊条的水平,可以取代同类进口焊条。 相似文献
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T91钢高温变形特性研究 总被引:9,自引:1,他引:8
利用Gleeble-1500热模拟试验机,研究了9Cr-1Mo-V-Nb-N铁素体耐热钢在850℃~1250℃,接近实际生产变形速率时的高温塑性,做出塑性图和再结晶图。并通过分析真应力—真应变曲线,用Marquardt法回归出试验T91钢的变形抗力数学模型 相似文献
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针对BA-302炉的技术改造要求,就炉管更换材料进行发焊接工艺性评定试验,通过试验数据的分析,选择了钨极氩弧焊封底,手弧焊盖面的焊接工艺,焊接材料分别采且TGS-TCM焊丝与R507焊条。还介绍了焊后热处理的工艺及缺陷返修工艺。 相似文献
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研制了超低氢高韧性和接头全位置立向下焊条E8016-G。与进口焊条Philips27P进行管线钢现场施焊对比,表明研制焊条在工艺性能上接近,而内在性能优于进口焊条,适用于X65-X70管线钢焊接,可代替相应的进口焊条。 相似文献
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本文针对21/4Cr-1Mo与0Cr19Ni9异种钢的焊接问题,提出两种方案进行焊接工艺评定试验,经过一系列试验,确定了较佳的焊接材料,采用TIG焊TG-82焊丝封底,A412焊条盖面,所得试件的各项性能指标符合要求,实践证明,采用氩弧焊封底,镍基时材盖面或采用基焊材堆焊过渡层,25Cr-20Ni盖面进行异种钢的焊接,可以保证高温管道的安全运行。 相似文献
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研制了一种用于对辊破碎机耐磨堆焊焊条,通过反复调整焊条药皮成分,找到了适合对辊破碎机机齿堆焊的合金来,通过堆焊层的金相显微分析及X射线物相分析表明:新研制的对辊破碎机耐磨堆焊焊条组织为马氏体+碳化物+残余奥氏体,堆焊层的硬度在HRC64-65之间,耐磨试验和工业试验证明,对辊破碎机堆焊合金的耐磨性能优良,是35CrMoTi钢的8.6倍,比未堆焊的破碎机使用寿命提高7.8倍。 相似文献
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Prestressing steels can be exposed in prestressed concrete structures in construction stage (ungrouted duct) to environmental conditions causing formation and growth of hydrogen induced cracks with brittle fracture of the steel. The risk of this hydrogen induced stress corrosion cracking can be minimized by appropriate treatment, but there is a requirement for construction to approve only prestressing steel having no enhanced susceptibility to stress corrosion cracking. The paper describes the historical development of the different test methods proposed in the past and gives an overview on the general requirements for a suitable test method to assess the hydrogen‐induced stress corrosion susceptibility of prestressing steels. Since 1982, based on investigations on construction sites and transfer of the results into laboratory tests, a test method is available enabling realistic estimation of suitable application possibilities of prestressing steels. This so called DIBt‐test is approved to distinguish between prestressing steels susceptible to hydrogen induced stress corrosion cracking and those suitable and therefore approvable steels at practical environmental conditions. Furthermore the test enables estimation of corrosion risk for newly developed prestressing steels with higher strength. 相似文献
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迄今,核电设施的焊接用镍基合金电焊条都依赖进口。为此,成功研制了核级ENiCrFe-7镍基合金电焊条,并在低合金钢板上制备了约20mm厚的堆焊层。随后检测了焊缝金属的宏观和微观形貌及室温和350℃力学性能,并对其进行了弯曲试验、剪切试验、晶间腐蚀试验和STF(strain-to-fracture)试验。结果表明:焊缝金属的宏观质量、微观组织、力学性能和耐晶间腐蚀性能均符合第三代先进压水堆核电站的要求,并且对高温失塑裂纹(DDC)不敏感。新研制的核级ENiCrFe-7镍基合金电焊条的综合性能与进口焊条的相当,有望替代进口的焊条。 相似文献
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本文利用G-BOP 试验方法探讨了铌含最对低合金钢手工电弧焊焊缝氢裂纹敏感性及其显微组织的影响。结果表明,增加焊缝中的铌含量会增大焊缝氢致裂纹的敏感性,但当铌含量低于0.03%时,看不到这种有害倾向.降低焊缝中的氢含量能有效地降低焊缝的氢裂倾向。但随铌含量增高,这种效应减弱。铌能抑制焊缝中晶界铁素体生长,促进铁素体与第二相(即魏氏组织)形成。本文讨论了其机理,并提出了新的设想.通过回归分析得出焊缝氢致裂纹率Pc 与铌含量、焊接线能量E、焊缝含氢量H_(?w)以及母材预热温度T_0之间的关系式。 相似文献
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《Science & Technology of Welding & Joining》2013,18(6):516-522
AbstractA low transformation temperature (LTT) welding consumable has been developed to prevent cold cracking in high strength steel welded joints without preheating. In the LTT welded joint, the residual tensile stress is reduced by martensitic expansion of weld metal formed by the LTT consumable. In the weld cracking tests, cold cracking in the LTT weld metal is successfully prevented under high restraint conditions, but cold cracking occurs at very low joint restraint strength in case the weld metal is fully martensitic. Chemical compositions of the consumable are designed to retain austenite in martensite in the newly developed weld metal to absorb the diffusible hydrogen into the austenite to prevent cold cracking. In the newly developed LTT weld metal, cold cracking is almost fully suppressed without preheating under every joint restraint condition. 相似文献
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采用连续可变拘束热裂纹试验方法研究了在A302、A402焊条配方中改变Cr/Ni比对焊缝抗热裂纹性能的影响,并探讨了该比值的变化对焊缝形成双相组织的作用.使所研制的焊条在异种钢焊接中得到了成功的应用. 相似文献
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Stress corrosion cracking of the magnesium alloy Elektron 21 (ASTM–EV31A) and AZ91E was studied using constant load test in 0.1 M NaCl solution (saturated with Mg(OH)2), and slow strain rate test using glycerol, distilled water and Mg(OH)2 saturated, 0.01 M and 0.1 M NaCl solutions. Slow strain rate test indicated that EV31A was less susceptible to stress corrosion cracking than AZ91E. Under less intense loading of constant load, EV31A was found to be resistant to stress corrosion cracking. Fractography of EV31A specimens showed little evidence of hydrogen embrittlement. The superior resistance of EV31A is attributed to a more robust oxide/hydroxide layer. 相似文献