2Cr12NiMo1W1V不锈钢Φ180 mm棒材低倍中心黑色区缺陷分析和退火工艺改进

2Cr12NiMo1W1V钢Φ180 mm棒材的生产工艺流程为80 t BOF-VD-LF-ESR 6 t锭-锻造-900℃退火。2Cr12NiMo1W1V不锈钢棒材成品低倍组织中出现GB/T1979-2001《结构钢低倍组织缺陷评级图》中无对应类型的中心黑色腐蚀区域缺陷,分析得出,该钢退火后的正常组织为铁素体基体+碳化物,而中心区域为板条马氏体+托氏体,托氏体耐腐蚀性差,形成黑色区域。将原先的退火工艺优化为900℃-700℃等温退火工艺,可保证全截面组织的均匀转变。该工艺可消除和避免2Cr12NiMo1W1V钢棒材中心黑色区域。

汽轮机叶片用2Cr12NiMo1W1V不锈钢偏析缺陷成因分析及改善措施

汽轮机叶片用2Cr12NiMo1W1V不锈钢心部易出现偏析缺陷,影响产品合格率。通过试验研究和分析了偏析缺陷产生的原因。结果表明:试验钢出现偏析缺陷是由于其精炼后凝固过程中冷却速度和电渣重熔过程中熔池凝固速度均偏慢。通过改进冶炼工艺,将试验钢浇注温度和电渣重熔速度均降低,可有效改善偏析缺陷。

1Cr12Ni2W1 Mo1 V不锈钢金相组织的探讨

本文较为系统地探讨了 1Cr1 2Ni2W 1Mo1V不锈钢在各种状态下的金相组织 ,为进一步熟悉该钢性能提供了可靠依据。

X22CrMoV121V不锈钢锻件的生产试制

介绍了X22CrMoV121V不锈钢锻件制造工艺流程,通过在冶炼过程中严格按X22CrMoV121V钢的化学成分进行控制,制订合理的冶炼、锻造、热处理工艺制度,确保了锻件毛坯在锻造、热处理过程中可以承受较大的应力而不开裂,从而获得优良的综合力学性能。

新型环保纸模制品用不锈钢模具材料的开发

设计的试验钢(0.45C-12.5Cr-0.41Mo-0.22V钢和0.85C-10.5Cr-0.91Mo-0.25V钢)由50 kg真空感应炉熔炼并锻造成试验用钢样。试验研究了淬火温度(950~1150℃)、回火温度(一次回火200~400℃,二次回火500~600℃)对钢的组织、强度、延伸率、硬度和冲击功的影响。结果表明,1 050℃淬火+500℃二次回火处理后0.45C-12.5Cr-0.41Mo-0.22V钢的性能最佳:抗拉强度为1 712.3 MPa、屈服强度为1 476.5 MPa、延伸率为7.8%、HRC硬度值为69.3以及冲击功为7.3 J。二次硬化会提升模具钢的硬度值,而回火过程中碳化物的长大以及分布不均匀容易造成冲击韧性的降低。试验的新型不锈钢模具的强度指标高于普通商用模具钢42Cr3Mo2MnV1。

高强马氏体不锈钢疲劳性能及裂纹扩展的研究

通过疲劳试验研究1Cr12Ni2W1Mo1V马氏体不锈钢的疲劳性能和裂纹扩展,并对断口形貌进行扫描分析。结果表明:1Cr12Ni2W1Mo1V钢疲劳强度为518 MPa,疲劳裂纹门槛值ΔKth为3.619 8 MPa·m1/2,符合奥金格公式;断口处分布大量的韧窝和撕裂棱,表现为脆性断裂特征,但是在瞬断区可见撕裂棱,表现为韧性断裂特征。

An Effect of Temperature and Notch Geometry on Correlated Toughness of a Stainless Steel

To determine the toughness of materials, Charpy V notch test has been widely used over the world. Originally, the Charpy-V or U tests were used mainly as a quality control tests. In this paper, effects of temperature and notch geometry on variation of toughness/yield stress ratio were investigated. The experimental work has been performed on austenitic stainless steel 316L using Charpy tests and carried out at temperature range from 20 ℃ to 250 ℃ on different dimension of V- and U-notch specimens. Energy of fracture was determined directly from machine tests. Furthermore, Barsoum correlation has been applied to determine toughness/yield stress ratio as function of temperature. In addition, several parameters were investigated namely specimen thickness and notch cut angles. U-notch specimen offers a high resistance comparatively to the V-notch and that toughness depends on temper situation and orientation of notch relative to the rolling direction.