含硼生铁冶炼硼钢新工艺及其硼钢性能研究

含硼生铁是高炉火法分离硼铁矿提取硼时(富硼渣,w(B_2O_3)≥12%)产生的另一种重要产品.研究了以此为原料直接冶炼硼钢的新工艺及硼钢试样的力学性能,结果表明:采用预脱硫、脱硅处理得到含硼半钢再冶炼硼钢的新工艺,其S、P等杂质含量均能满足硼钢标准要求,而最关键的B含量(质量分数)也可控制在0.0005%～0.0035%,即硼钢要求的标准范围;其硼钢试样材料的拉伸、冲击韧性等力学性能指标优于20Mn2、15MnVB,而与40MnB、45MnB结构合金硼钢相当;通过冶炼后期控制其它合金化成分,能达到国标GB/T 3077-1999中相近成分的硼钢性能.     

采用TMCP工艺对高强度船体结构钢EH50的研究与开发

 采用TMCP工艺,在实验室对含硼钢和不含硼钢的显微组织和力学性能的变化规律进行了研究。实验结果表明：采用相同的冷却条件,含硼钢的强度明显高于不含硼钢,但伸长率和冲击功低于不含硼钢,且冲击功很不稳定;对于高强度船体结构钢EH50,采用含硼钢,强度和伸长率能达到船级社要求,但冲击功容易出现不合,不含硼钢的强度和韧性能很好地匹配,相对含硼钢具有较低的韧脆性转变温度,建议大生产条件下,采用不含硼钢生产高强度船体结构钢EH50。     

低碳微合金化含硼冷镦钢的力学性能研究

实验室试制了低碳Nb、V微合金化含硼冷镦钢,并对试验钢的组织和性能进行了对比研究.结果表明:钢中添加适当的Nb、V细化了含硼钢的铁素体晶粒,显著提高了含硼钢的抗拉强度,其中,Nb、V复合微合金化含硼钢的效果最好,其次是含钒硼钢和含铌硼钢.分析表明,Nb、V复合微合金化在含硼钢中的主要作用在于细化晶粒和沉淀强化.     

硼钢炼钢连铸技术发展现状

概述了硼钢的分类和应用现状,分析了硼钢炼钢、连铸技术研究的进展:日本住友金属公司在钢中添加钛和硼来细化奥氏体晶粒、安赛乐米塔尔公司研究硼在连铸坯中的偏析、东北大学研究的硼钢生产新工艺。介绍了日本住友金属、日本新日铁和韩国浦项公司生产硼钢在精炼和连铸阶段的关键控制技术,以及国内宝钢、武钢和攀钢和鞍钢等钢厂生产硼钢的工艺现状;指出了硼钢的研究及发展方向。     

标准样品的管理

目前,我厂使用的标准样品有:碳素钢、低合金钢、高锰钢、镍铬不锈钢、高温耐热钢、硼钢、铬钨钢、滚动轴承钢、高硅铝合金、生铁、铬钼铜合金、铸铁、稀土球墨铸铁、高铬铸铁、合金铸铁、中低碳素锰铁、中低炭素铬铁、硅铁、钛铁、烧结矿、高炉渣、锰矿、电炉渣、石灰石、萤石、硅砖、铬镁砖、镁砂、焦炭、煤等系列标准样品。在配合分析使用时,如何尽快的选择随心所需的标准样品,一度成为难题。现在能非常方便、快速、准确的找到。我们的做法如下:(1)建立台帐:新购回标准样品按不同系列分类,每瓶有新编序号,对标准样品的原编号、产地、…     

硼及回火温度对超高强海洋工程用钢板组织及性能的影响

为改进调质态超高强海洋工程用钢的力学性能,研究了2炉不同硼含量的钢。经控制轧制后,在实验室条件下采用不同回火温度处理以确定最佳热处理温度,并对实验钢板进行金相组织观察,利用扫描电镜和透射电镜讨论分析了硼及回火温度对组织、性能的影响。实验结果表明,硼有利于提高钢板的淬透性,含硼钢600℃回火可以满足E690的性能要求;随回火温度的提高,含硼钢和无硼钢的强度降低,伸长率升高,含硼钢的变化幅度比无硼钢大;含硼钢在630~660℃存在明显的回火脆性区,而无硼钢具有较好的回火稳定性;无硼钢在650℃回火可以满足E550的性能要求。     

矩形坯连铸生产含硼钢试验

借鉴国内钢厂电炉工艺生产含硼钢的成功经验 ,设计了首钢生产含硼钢的内控成分和关键工艺 ,用BOF -LF -CC工艺批量生产出优质含硼钢。     

新标准15种硼钢的试制与研究

提出新标准全部硼钢进行生产试制的结果,对硼钢的冶炼、轧制、锻造、热处理、检验提出了比较宪整的数据与看法,肯定新标准硼钢可以正式生产供应,并通过试制、对硼钢的一些特殊性能作了进一步研究与分析探讨     

硼对低焊接裂纹敏感性高强钢组织性能的影响

 分析了在控轧、控轧加回火、调质等不同工艺条件下,硼对低焊接裂纹敏感性钢显微组织和力学性能的影响。结果表明,硼抑制先共析铁素体形成,提高淬透性,在控轧工艺下含硼钢形成粗大的贝氏体和马氏体组织,并保留了原始奥氏体晶界;调质工艺得到回火索氏体组织,但含硼钢的大角度晶界比例与无硼钢相比较低。硼在强度上的作用显著,上述3种工艺下含硼钢的抗拉强度分别比无硼钢高300, 214, 101MPa,屈服强度分别高320,259,144MPa,但伸长率和冲击韧性均有所降低。无硼钢在调质工艺下、含硼钢在控轧加回火工艺下具有较好的强韧性匹配。     

板坯含硼钢裂纹产生机理及工艺改进

济钢中厚板厂在生产含硼钢种时出现较多表面横裂纹问题,文章对含硼钢种产生裂纹的机理进行了研究,并结合济钢中厚板厂炼钢工序的实际工艺过程,提出了控制含硼钢裂纹的工艺改进办法,实施后取得了良好效果。     

Influence of microalloying with boron on the structure and properties of high-strength oil pipe

Microalloying with boron (up to 0.005%) has a considerable influence on the hardenability of steel. Four alloying systems with complete and partial replacement of molybdenum by microadditions of boron are studied. The resulting mechanical properties are satisfactory for high-strength pipe corresponding to strength groups from N80 (type Q) to Q135, according to the API 5CT, ISO 11960, and GOST R 53366 standards. The reversible tempering brittleness of Nb-B steel and Mo-B steel is considered. Overall, the strength and impact strength of Mo-B steel are greater than for steel without molybdenum.     

含硼钢试验开发

本次试验开发含硼钢,相继试验了含硼烧结矿、含硼铁水和铁块、含硼钢坯、含硼钢材中硼元素的变化规律,并结合我公司的工装条件,确认了各环节的工艺可行性,为同行业的工艺实现提供参考,以及合理利用硼资源。     

微量硼对热轧低焊接裂纹敏感性钢力学性能的影响

采用相同轧制工艺试制低焊接裂纹敏感性钢,对比分析了微量硼元素对显微组织和力学性能的影响.结果表明:含硼钢的屈服强度和抗拉强度比无硼钢分别要高150和105MPa,但冲击韧性明显低于无硼钢.显微组织分析可知,硼的偏聚机制使组织中保留了明显的原始奥氏体晶界,并获得具有较大有效晶粒尺寸的板条贝氏体束,同时在贝氏体板条晶界上分...     

硼对铬锰钼系含硼调质钢淬透性的影响

以实验室冶炼的铬锰钼系含硼调质钢为材料,通过末端淬火实验和微观组织分析,研究了硼元素对铬锰钼系含硼调质钢淬透性的影响.结果表明,硼元素对实验钢所表现的淬透性效果,仅在一定的区间(J11～J40)内作用明显,在这个区间内,淬透性随酸溶硼(Bsol)含量的增加而升高,且当Bso1质量分数为0.001 2％左右,其淬透性最好...     

硼对780 MPa低碳贝氏体钢组织和力学性能的影响

试验低碳贝氏体钢（/%:0.08C,0.11~0.13Si,1.10~1.20Mn,0.008~0.009P,0.002S,0.21~0.23Ni,0.020~0.021Ti,0.003~0.004Nb,0~0.0010B,0.000 7~0.0008O,0.0031~0.0033N）由50kg真空感应炉熔炼,轧成45mm钢板,并经930℃淬火,610℃回火。研究了0.0010%硼对780 MPa低碳贝氏体钢45mm板组织和力学性能的影响。结果表明,硼可显著提高试验钢的淬透性,不含硼试验钢淬火后得到粒状贝氏体,0.0010%硼试验钢淬火后得到板条贝氏体。硼明显改善试验低碳贝氏体钢的力学性能,含0.0010%硼试验钢淬、回火后的抗拉强度834MPa和屈服强度771MPa远高于不含硼试验钢的抗拉强度702MPa和屈服强度591MPa,实际生产中应加入适量硼可使低碳贝氏体钢得到板条贝氏体。     

提高S43BCH钢硼回收率的工艺技术研究

合作炼钢厂主要通过BEF-LF-VD-CC流程生产含硼钢,由于成品钢所得有效硼含量低会影响钢材淬透性能,所以采用喂硼合金芯线的方式提高有效硼含量,进而保证了钢材的淬透性能。     

Distribution of boron between oxide slag and steel

The influence of silicon (0.1–0.8%), aluminum (0.005%), and carbon (0.1%) in steel on the reduction of boron from slag (basicity 5) at 1400–1700°C is studied by thermodynamic analysis on the basis of HSC 6.1 Chemistry software (Outokumpu). Experiments on the boron distribution between CaO–SiO₂–MgO–Al₂O₃–B₂O₃ slag and steel are conducted in a high-temperature Tamman resistance furnace. Low-carbon steel with different silicon content is employed. According to the thermodynamic modeling and the experiments, direct microalloying of steel with boron is possible on the basis of its reduction by the silicon present in the steel. The reduction of boron from slag by silicon is theoretically analyzed and experimentally confirmed. The results of thermodynamic modeling indicate that boron may be reduced from CaO–SiO₂–MgO–Al₂O₃–B₂O₃ slag by silicon despite its low content in the steel (0.1–0.8%). With increase in the initial Si content in the steel, the boron concentration in the steel also increases. The influence of the Si content and the steel temperature on the final boron content is studied. When steel is held under slag containing 4.3% B₂O₃, the boron is reduced, mainly by silicon, whose content in the steel is 15–22% lower after the experiment. More boron is present in the steel sample with an elevated Si content. The degree of assimilation of boron is 5.8–6.9%; this is consistent with the thermodynamic modeling. The boron content in the metal may be regulated by adjusting the temperature and the silicon content of the steel. On the basis of the results, a technology for the direct microalloying of steel with boron may be developed.     

Physicochemical characteristics,production and application of boron-bearing complex ferroalloys

The expediency of producing and using complex ferroalloys in steelmaking is analyzed in terms the manufacturing technology, the raw materials employed, and the interactions of the ferroalloys with the molten steel. The need to produce complex ferroalloys with boron is established. The fundamental principles for determining the best composition of such alloys are presented. The basic compositions of complex ferroalloys with boron (ferrosilicomanganese with boron, ferrosilicon with boron, ferrosilicomanganese with boron and chromium) are established by studying the physicochemical properties of alloys and their interactions with the steel melt. If the characteristics (melting point, density, melting time of the ferroalloy in liquid steel, etc.) of complex ferroalloys with boron are compared with those of ferroboron, which is widely used, the complex alloys have clear benefits. The composition of the complex ferroalloys with boron includes active elements (Si, Al, Ti) facilitating the binding of oxygen and nitrogen from the steel melt in strong compounds and hence preventing their reaction with boron. The recommended boron content in the ferroalloy is 0.7–2%. That permits increase in the quantity of complex ferroalloys with boron in the steel and hence increase in the reliability and stability of boron assimilation. At elevated temperatures (1430–1570°C), the oxidation of ferrosilicoboron is 4–7 times less than that of ferroboron. Data are presented regarding the industrial production and use of ferrosilicoboron in the steel-smelting shop. The boron assimilation from complex alloys in microalloying of the steel is studied. The use of ferrosilicoboron does not require significant changes in the existing system for reduction by ferrosilicon; the boron assimilation is 77.8–96.3% (mean 86.6%). With a boron concentration of 0.0021–0.0027% in the steel during ladle treatment, its content in the cast metal will be no less than 0.0020%. If boron is introduced in steel by means of ferrosilicomanganese with boron, the boron assimilation is increased by a factor of 1.6 (from 48 to 77%, on average) in comparison with the use of ferroboron.     

硼对Ti-IF钢力学性能及再结晶过程的影响

 研究了硼对Ti-IF钢热镀锌板组织和力学性能的影响,并从硼对冷轧后再结晶过程影响的角度解释了硼对组织性能影响的原因。利用万能试验机、光学显微镜和透射电子显微镜对不同硼质量分数IF钢热镀锌板的力学性能、组织和析出物进行检测,采用X射线衍射仪对织构取向密度进行分析,采用电子背散射衍射技术（EBSD）对镀锌板晶界取向差分布进行分析,利用显微硬度计和金相显微镜研究了硼对IF钢再结晶过程的影响。结果表明,硼质量分数在0.000 5%以内,随着硼质量分数的提高,Ti-IF钢热镀锌板铁素体晶粒尺寸降低,屈服强度和抗拉强度提高,塑性应变比降低。硼对Ti-IF钢力学性能产生影响的原因为,硼固溶于铁素体中,抑制再结晶过程,提高再结晶温度,细化铁素体晶粒尺寸,使小角度晶界比例提高,{111}织构组分降低,从而使力学性能发生变化。     

硼钢的淬透性和硼淬透性因子及硼平衡集聚的研究

研究了硼淬透性因子与硼的晶界平衡集聚规律、钢的成分、奥氏体化温度及晶粒尺寸的关系。建立了硼的晶界平衡集聚方程。导出了由钢的成分（碳和合金元素）定量计算硼淬透性因子的二元回归方程。考察了硼淬透性因子随奥氏体化温度变化的单峰曲线规律；研究结果表明，硼钢的淬透性与奥氏体化温度无关。本还对传统的计算淬透性用各种图表进行了回归分析，建立了硼淬透性因子等一系列淬透性计算的关系式。