N对V-微合金化钢15MnVq的组织和性能的影响

通过100 kg真空感应炉,分别添加V-N合金和V-Fe合金熔炼成15MnVNq钢(%-0.15C、1.71Mn、0.11V、0.019 ON)和15MnVq钢(%:0.15C、1.72Mn、0.11V、0.003 3N),并轧制成14 mm钢板.试验结果表明,15MnVq钢中加入0.019%的N促进V(C,N)析出和明显细化钢的组织,钢的屈服和抗拉强度分别由393 MPa和578 MPa提高至510 MPa和660 MPa,-20℃冲击功AKV由21.9 J提高到101.8 J;同时加N后明显降低了15MnVq钢的时效敏感性.     

锰含量对15MnV钢组织性能的影响

采用热膨胀、热模拟和控轧控冷试验,研究了不同锰含量对15MnV钢相变点、组织和性能的影响。测试了不同锰含量钢的临界点、等温转变开始时间,观察了显微组织。确定了化学成分与15MnV钢临界点的回归公式,找出了锰含量及控轧后的终冷温度与组织细化的关系,并在此基础上进行了控轧控冷试验。试验表明,通过合适的控轧控冷,降锰后的15MnV钢性能可达原15MnV钢的水平。     

15CrMoR钢的显微组织与时效冲击性能

 为探索原始组织形态对15CrMoR钢时效过程低温冲击性能的影响,明确15CrMoR钢具有高时效冲击性能稳定性的原始组织形态,通过控制奥氏体化后的冷却方式获得了15CrMoR钢的3种原始组织,使用OM、SEM、EPMA和EBSD等材料结构表征方法和低温冲击测试研究了15CrMoR钢的显微组织和时效态低温冲击性能。结果表明,15CrMoR钢奥氏体化后分别以炉冷、空冷和风冷的方式冷却至室温,分别获得了粗大铁素体+片状珠光体组织、铁素体+退化珠光体组织和粒状贝氏体组织。片状珠光体组织中碳化物主要呈层片状,退化珠光体中的碳化物主要呈断续短杆状和颗粒状,粒状贝氏体中的富碳M-A岛主要沿晶界分布。3种原始组织形态的15CrMoR钢在循环时效过程中均发生了晶界碳化物析出和长大,导致低温冲击性能不断恶化。当晶界碳化物呈链状分布时,15CrMoR钢的低温冲击性能较差。粗大的铁素体+片状珠光体组织晶界面积较少,导致晶界碳化物容易呈链状分布;粒状贝氏体中主要沿晶界分布的富碳M-A岛也容易导致晶界碳化物呈链状分布。因此,原始组织为铁素体+退化珠光体的15CrMoR钢在循环时效过程中具有较好的冲击性能稳定性,经历6次循环时效后,-10 ℃平均冲击吸收功仍高达196 J;而原始组织为铁素体+片状珠光体和原始组织为粒状珠光体的15CrMoR钢,经历4次循环时效后,晶界处已形成呈链状分布的碳化物,-10 ℃平均冲击吸收功均仅为18 J。     

低合金热强钢15CrMo的研制

本文介绍了15CrMo钢的冶炼、轧制工艺,并作了分析探讨。检验分析了该钢的化学成分、机械性能、显微组织,晶程度及电解夹杂等。结果表明:我公司首次研制的15CrMo特厚钢板(85mm)的各项性能均满足技术协议要求,这说明现行的生产工艺是可行的。另外,本文作了该钢的热轧与热处理、表面与心部性能、显微组织等对比试验及中温拉伸、V型冲击、回火脆性等试验研究,为我公司进一步开发该钢奠定了一定的基础。     

汽车传动轴管用15Ti冷轧带钢的研制

用15Ti冷轧带钢试制制φ89×2.5mm汽车传动轴管,取代23.5号钢.主要是在钢中加入钛,使其形成TiC,并利用TiC弥散强化作用,细化晶粒,以提高钢的强度,而传动轴的扭矩也相应提高;由于15Ti钢的碳当量略低于23.5号钢,因此可改善焊接性能;钛与硫的亲和力大于锰和硫的亲和力,生成钛的硫化物,减少了MnS夹杂,并改变其形态,从而提高了成型性能.试验证明了15Ti钢综合性能合格率为100%.锭到材成材率为65.7%,这两项指标均优于23.5号钢。     

SWRCH15A钢盘条生产工艺优化

针对SWRCH15A钢抗拉强度偏低的问题,通过生产工艺调整,优化关键控制过程和相应参数,提高盘条抗拉强度和其他性能,改善金相组织,满足了客户需求.     

15Ni?15Cr ODS钢的微观结构与力学性能

氧化物弥散强化（Oxide dispersion strengthened, ODS）钢因其良好的高温力学性能和抗辐照性能被认为是钠冷快堆包壳材料的重要候选材料. 本文通过机械合金化以及热等静压和锻造工艺制备了15Ni?15Cr ODS奥氏体钢,并且采用相同工艺制备了不加氧化物的15Ni?15Cr奥氏体钢作为参比材料. 利用透射电镜对样品的微观结构进行分析,发现15Ni?15Cr和15Ni?15Cr ODS奥氏体钢晶粒尺寸分别为0.75和0.5 μm. 15Ni?15Cr ODS奥氏体钢中分布的氧化物弥散粒子主要为δ-Y₄Zr₃O₁₂以及少量的Al₂O₃. 15Ni?15Cr ODS奥氏体钢中氧化物弥散粒子的平均粒径为12.8 nm、数密度5.5×1022 m?3、粒子间距26 nm. 相比于15Ni?15Cr奥氏体钢,15Ni?15Cr ODS奥氏体钢具有更高的强度,但是高温塑性有所降低. 15Ni?15Cr ODS奥氏体钢的室温断裂机制为韧性断裂,高温断裂机制为韧–脆混合断裂.      

提高15MnHP钢冲压性能的研究

本文通过对15MnHP 钢的生产检验数据的统计分析,用多目标优化的思想,提出采用前段冷却、降锰、增碳等措施,以降低15MnHP 钢的屈强比和提高延伸率,从而提高冲压性能。实践结果验证了上述措施的正确性。     

微钛处理15MnVN钢熔合线韧性的改善

针对桥梁用15MnVN钢焊接熔合线韧性恶化问题,在低碳、低硫化基础上进一步探索了微钛处理的效果。发观未经微钛处理的钢焊接粗晶区晶粒粗大,冲击韧性较差的主要原因是母材中原有的细小弥散的V(C,N)粒子经受不住焊接高温,绝大部分又重新固溶于基体中,且在焊后冷却条件下难于再析出。而加入微量钛(0.028％Ti的15MnVN钢的粗晶区晶粒及组织显著细化,冲击韧性显著提高。即使在较大线能量焊接的模拟条件下,稳定性较高的细小Ti,V(C,N)复合粒子仍然大量存在于粗晶区中,从而起到抑制晶粒长大,细化二次组织等作用,使熔合线韧性明显改善。     

GCr15钢M／B复合组织疲劳性能的研究

本文研究了GCr15钢中两种工艺获得的M/B复合组织(含35～45％B_下)和常规淬火组织的疲劳性能。结果表明,在相同硬度条件下,M/B复合组织的疲劳性能优于回火马氏体组织。     

Effects of Finish Rolling Temperature on Microstructure and Mechanical Properties of Ferritic-Rolled P-Added High Strength Interstitial-Free Steel Sheets

  The steels were rolled at 3 different finishing temperatures. The mechanical properties were tested by tensile tests. The results show that as finish rolling temperature decreases from 620 to 560 ℃ in ferrite region, the deep drawability of ferritic rolled P added high strength IF steels is improved, and r value rises from 114 to 137. Finish rolling temperature (FT) has less influence on other mechanical properties, such as yield strength, tensile strength and elongation. Microstructures of hot rolled and annealed steel sheets and precipitates of annealed steel sheets were also analyzed.     

Low Carbon High Nitrogen Low Nickel Stainless Steel

This article aims to investigate the effect of soluble and insoluble nitrogen on mechanical properties of stainless steels. Reference steel contains about 14.42%Ni and 0.012%N. Two developed steels have the same base chemical composition of the reference steel except Ni and N contents. One of the developed steels has 6.54%Ni and 0.232%N and the other has 0.452%N and nearly nickel free (0.089%Ni). The produced steels were forged, heat‐treated, and tempered. The microstructure of steels was mainly austenite, and grain size decreases as nitrogen content – especially nitrides‐increases. Yield and ultimate tensile strength of reference steel are less than that of steels containing nitrogen. Strengthening mechanisms contribution to the strength of both soluble and insoluble nitrogen had been analyzed.     

VN合金在大规格角钢生产中的应用研究

大规格角钢主要用于铁塔制造和建筑结构中。唐钢过去用16Mn钢生产Q345级别角钢，因供轧化学成分范围较窄，供轧率偏低。通过加入V-Fe合金及VN合金进行微合金化，设计了16Mnv(N)钢种生产角钢，使角钢综合性能有显著提高。分析比较了16Mn、16MnV及16MnV(N)角钢的性能，认为在大规格高强度角钢生产中，用VN合金进行微合金化，其效果是最佳的。     

首钢热轧酸洗先进高强钢的开发与进展

介绍了首钢热轧酸洗先进高强钢的开发与进展。根据客户的使用要求,结合生产设备,首钢研发了双相钢、高扩孔钢、复相钢、相变诱导塑性钢等系列高强钢。分析了双相钢、高扩孔钢、复相钢以及相变诱导塑性钢等产品的化学成分和力学性能,并利用金相显微镜和扫描电镜等手段对微观组织特征进行了描述。首钢热轧酸洗先进高强钢因出色的力学性能已经在汽车控制臂和纵梁等零件上得到广泛应用,未来将在乘用车减重和安全等方面发挥更大作用。     

Improvement of Mechanical Properties of Reinforcing Steel Used in the Reinforced Concrete Structures

SAE1010 structural carbon steel, which has a low cost price and wide range of use in the construction industry, has been studied as dual phase (DP) steel subjected to appropriate heat treatment, and its mechanical properties have been investigated under various tempering conditions. Intercritical annealing heat treatment has been applied to the reinforcing steel in order to obtain DP steels with different martensite volume fraction. In addition, these DP steels have been tempered at 200, 300 and 400 °C for 45 min and then cooled to the room temperature. Mechanical properties such as tensile strength, yield strength, reduction in cross-sectional area, total elongation, resilience modulus and toughness have been examined. Furthermore, fractographic examination has been done with scanning electron microscope (SEM) as well as metallographic examination of the steels. As a result of this study, it is found that mechanical properties of DP steel have changed according to the hardness and ratio of martensite phase. In addition, tensile strength, yield strength and resilience modulus of the steels have been reduced. In contrast, the total elongation, reduction of the cross-sectional area and toughness have been increased.     

Development of nitrogen-alloyed stainless steel sheet products in Baosteel

Nitrogen plays a vitally important role for improving properties for stainless steels in many aspects.In this paper,the physical metallurgy behavior and the beneficial effects of nitrogen on corrosion resistance and other mechanical properties of stainless steels were summarised.Based on nitrogen alloying,various stainless steel products,such as austenitic,duplex and martensitic staniless steels were developed with enhanced properties,such as corrosion resistance,mechanical strength and weldability,among other things.     

Influence of Chromium on Mechanical Properties and CO2/H2S Corrosion Behavior of P110 Grade Tube Steel

Four kinds of P110 grade tube steels containing different chromium contents were designed to probe the in- fluence of Cr on the properties of tube steel. The microstrueture, mechanical properties and corrosion behavior of the four kinds of P110 grade tube steels were studied deeply and thoroughly. The analysis of the mechanical properties indicated that tensile strength and yield strength of the steel plates were improved, while transverse and longitudinal impact energy and elongation first increased and then decreased when Cr content rose. The impact energy and elonga tion reached the peak when Cr content was 1 ~. Cr precipitates were found only in 3 ~ Cr steel, with （Nb, Ti）（C, N） or Nb（C,N） as the core of precipitation and then grew up. The corrosion experiments demonstrated that the scales on the four steels had a two layer structure under the corrosion of CO2 and H2 S. The outer layer was mainly com- posed of FeS or FeS1 x and the inner layer consisted of FeCOa and Cr compounds. Cr was rich in the inner layer and the Cr content of the inner layer increased with the Cr content in matrix. The enriched Cr enhanced the compactness of the scales, further hindering the diffusion of ions from liquid to the surface of steel, thus reducing corrosion rate.     

BN型易切削钢中夹杂物的控制及对切削性能的影响

汽车曲轴用钢42CrMo要求在不影响力学性能的前提下,具有较好的切削性。传统的钢种无法满足使用需求,通过在钢中添加B、N元素,并对钢中夹杂物进行控制,以满足性能要求。首先通过坩埚熔炼实验得到不同B、N含量的试样;其次利用FactSage软件计算出理想条件下不同B、N含量的钢液中各种夹杂物的析出量及析出温度;然后通过对试样设置不同的冷却方式和定向凝固实验,得到钢中BN夹杂物的形貌、尺寸及分布的影响因素;最后,通过切削实验研究了夹杂物对切削性能的影响因素,最终得到理想切削性能的BN型易切削钢。结果表明,尺寸较小而密度较大的BN夹杂物对钢的切削性能的改善作用更好。切削性较好的试样,其切削性能已达到与硫系易切削钢Y1215同等水平。     

Effect of Adding Nitrogen on Microstructure and Property of Vanadium Microalloyed Reinforcing Bar Steel

Worldwideattentionhasbeenpaidtomicroal loyedsteelwhichhasbeendevelopedrapidly .Manyadvantagesofmicroalloyedsteelhavebeenrecog nizeddeeply .Firstly ,themicroalloyedsteelhashighstrengthand goodcomprehensiveproperties .Sec ondly ,highprofitscanbegainedduetolowerpro ductionandapplicationcost .Themicroalloyingele mentsareaddedtomicroalloysteelsforgrainrefin ingandprecipitationstrengthening[1] .　　Theabilityofsecondphaseparticlestomaintainfinegrainsizesathightemperaturebypinningmi gratingboundarie…     

Effects of Warm Deformation on Mechanical Properties of TRIP Aided Fe-C-Mn-Si Multiphase Steel

 Warm deformation tests were performed using a kind of tubby heater. The microstructures and mechanical properties of an Fe-C-Mn-Si multiphase steel resulting from different warm deformation temperatures were investigated by using LOM (light optical microscopy), SEM and XRD. The results indicated that the microstructure containing polygonal ferrite, granular bainite and a significant amount of the stable retained austenite can be obtained through hot deformation and subsequent austempering. Warm deformation temperature affects the mechanical properties of the hot rolled TRIP steels. Ultimate tensile strength balance reached maximum (881 MPa) when the specimen was deformed at 250 ℃, and the total elongation and strength-ductility reached maximum (38% and 28614 MPa·%, respectively) at deforming temperature of 100 ℃. Martensite could nucleate when austenite was deformed above Ms, because mechanical driving force compensates the decrease of chemical driving force. The TRIP effect occurs in the Fe-C-Mn-Si multiphase steel at deforming temperature ranging from 15 to 350 ℃. The results of the effects of warm deformation on the mechanical properties of the Fe-C-Mn-Si multiphase steel can provide theoretical basis for the applications and the warm working of the hot rolled TRIP sheet steels in industrial manufacturing.