690MPa级大厚度调质高强钢板组织性能研究

对152.4 mm特厚高强度NVE690钢板的调质工艺与组织、性能的关系进行了研究,确定了生产条件下合适的调质工艺参数:即930℃两次淬火+650℃回火。采用此工艺生产,钢板可以获得最佳的组织和性能,满足了强度和冲击韧性要求。     

自升式海洋平台齿条用177.8mm厚度钢板的研制开发

介绍了舞钢研制开发的自升式海洋平台桩腿齿条用177.8 mm厚度A517Gr Q钢板的技术要求、生产工艺特点,对钢板实物质量水平进行了常规性能检验,同时进行了焊接评定。结果表明:舞钢生产的大厚度齿条钢板钢质纯净,杂质元素含量低,化学成分均匀,并且具有良好的综合力学性能和焊接性能。     

自升式钻井平台支撑系统用Φ406mm×45 mm大口径厚壁X100QO无缝钢管的开发

根据自升式钻井平台支撑系统用管的服役条件及使用要求,设计了X100QO厚壁钢管的化学成份。采用"70 t电弧炉冶炼→LF+VD→连铸Φ460 mm圆坯→ASSEL机组轧管→调质热处理"工艺流程生产Φ406 mm×45 mm规格X100QO大口径厚壁无缝钢管。通过生产过程控制钢的纯净度及尺寸精度,并根据试验结果确定了950℃淬火,水冷,530℃回火,空冷的热处理工艺。检测结果表明,该无缝钢管具有高强度及优良的冲击韧性、焊接性能好,完全满足自升式钻井平台支撑系统用管的设计及使用要求,并通过了ABS美国船级社的认证。     

自升式钻井平台支撑系统用Φ406mmx45mm大口径厚壁X100QO无缝钢管的开发

根据自升式钻井平台支撑系统用管的服役条件及使用要求,设计了X100QO厚壁钢管的化学成份。采用"70 t电弧炉冶炼→LF+VD→连铸Φ460 mm圆坯→ASSEL机组轧管→调质热处理"工艺流程生产Φ406mm×45mm规格X100QO大口径厚壁无缝钢管。通过生产过程控制钢的纯净度及尺寸精度,并根据试验结果确定了950℃淬火,水冷,530℃回火,空冷的热处理工艺。检测结果表明,该无缝钢管具有高强度及优良的冲击韧性、焊接性能好,完全满足自升式钻井平台支撑系统用管的设计及使用要求,并通过了ABS美国船级社的认证。     

回火热处理对460MPa级海洋平台用钢板性能影响研究

采用低碳的成分设计以及轧后调质工艺,开发出满足标准的50 mm厚460 MPa级钢板,并研究了回火温度对组织性能的影响。结果表明：在此成分设计的条件下,调质态的组织为回火贝氏体和M/A,此类组织具有优良的综合力学性能,而且在较宽的回火温度范围内获得良好的性能匹配。     

欧标耐低温高强钢的开发生产

莱钢根据EN 10025标准及用户使用要求，合理设计成分及轧制工艺，采用低碳高锰添加Nb-Ti-Ni微合金化的成分体系，通过洁净钢冶炼、TMCP控轧控冷工艺开发生产6～60 mm厚欧标355 MPa级别低合金高强钢板。该钢性能稳定，在保证钢板较高强度和良好焊接性的同时，具备较佳的低温冲击韧性，各项性能指标均满足标准和用户要求。     

海洋平台用E550级钢板的试制开发

通过分析钢的成分及性能要求,设计了低碳Nb、V、Ti微合金化成分,设计了两阶段轧制工艺,在高温区大压下量轧制,低温区大压缩比轧制,配合920℃淬火、630℃回火的调质处理工艺,开发了60 mm厚海洋平台用E550钢板。钢板厚度方向组织均匀,主要为板条状贝氏体,少量粒状贝氏体、铁素体及一定量的M/A;屈服强度680 MPa,抗拉强度740MP,-40℃低温冲击功在200 J以上,达到了船级社规范要求。     

三级锚链及其附件用钢——30Mn_2VB的研制

本文论述了三级锚链及其附件用钢的成分设计及热处理工艺选择,特别是短时保温淬火、回火工艺的确定,找到了一条新的连续生产调质锚链的途径。 船用三级锚链及其附件所需钢材直径大,长度长,因此要求有高的强度和韧性,并且要求具有一定的焊接性能和耐海     

Q620D钢板连续冷却相变行为和回火工艺

以Q620D高强度钢板为研究对象,利用热模拟试验机研究了Q620D钢板连续冷却相变规律,同时对比分析了不同回火工艺对钢板组织和性能的影响,确定了Q620D钢板最佳的轧制和热处理工艺。结果表明,采用控制轧制+超快冷快速冷却+回火工艺生产Q620D钢板时,钢板轧制后冷却速率不低于20℃/s,回火温度控制在550~600℃,钢板的强度和韧性匹配最佳。回火过程中位错的回复和消失、M/A岛状组织的分解、马氏体组织的转变和铌、钒等微合金元素的析出强化等共同影响Q620D钢板回火后的强度和低温冲击韧性。     

Q420q-E厚板回火工艺探讨

针对Q420q-E厚板回火出现的屈强比升高的生产实际问题,对Q420q-E不同回火温度的组织转变进行研究,发现了不同回火工艺过程中析出物对钢板屈服强度的影响规律。Q420q-E生产中屈强比上升的主要原因是回火温度偏高,钢板中第二相ε-Cu颗粒及铌、钛的析出相,屈服强度上升;较低温度回火后,钢板内应力得以消除,钢板保持了TMCP的组织特征,低温冲击韧性保持较高水平,屈服强度没有明显上升,屈强比基本保持不变。提出了符合现场实际生产条件的回火工艺,即:(500±10)℃、(板厚+55)min、空冷,该工艺成功地应用于实际生产,生产的Q420q-E厚板满足了我国第一代高速、重载公铁两用大胜关长江大桥建设的要求。     

Development of high strength heavy plate A517Q for offshore platform rack

This paper introduces the research and development of high strength A517Q developed by Baosteel for platform rack,with micro-alloying adding suitable quenching and tempering process,trial thickness of 127 - 178 mm high-strength A517Q.The trial plate crossing thickness has a uniform mechanical properties, yield strength greater than 700 MPa,tensile strength than 790 MPa,the Charpy impact than 90 J at -40℃, aging impact than 69 J,has high strength and excellent low temperature impact toughness,While the plate has excellent resistance to crack tearing ability of low-temperature,NDT is less than -45℃.The Developing heavy plates had been used for manufacturing racks of 200-foot jack-up offshore platform,the performance meeting the requirements of the ABS,CCS classification societies.     

调质工艺对Q690D钢综合力学性能及组织的影响

 以60mm厚Q690D高强度结构钢板为研究对象,在相同轧制条件下,系统地研究了淬火、回火温度对试验钢综合力学性能及显微组织的影响,并对第二相析出进行理论分析。试验结果表明：随淬火温度升高,试验钢强度升高,韧性下降;随回火温度升高,试验钢强度下降,但韧性明显升高。该钢采用930℃淬火(保温10min)650℃回火(保温40min)的调质热处理工艺具有良好的强韧性匹配,综合力学性能最佳,满足国标GB/T 16270—2009要求。     

0420q-E厚板回火工艺探讨

针对Q420q-E厚板回火出现的屈强比升高的生产实际问题,对Q420q-E不同回火温度的组织转变进行研究,发现了不同回火工艺过程中析出物对钢板屈服强度的影响规律。Q420q-E生产中屈强比上升的主要原因是回火温度偏高,钢板中第二相ε-Cu颗粒及铌、钛的析出相使屈服强度上升;较低温度回火后,钢板内应力得以消除,钢板保持了TMCP的组织特征,低温冲击韧性保持较高水平,屈服强度没有明显上升,屈强比基本保持不变。提出了符合现场实际生产条件的回火工艺,即：500±10℃、（板厚＋55）min、空冷,该工艺成功地应用于实际生产,生产的Q420q-E厚板满足了我国第一代高速、重载公铁两用大胜关长江大桥建设的要求。     

Electroslag Remelting Withdrawing Technology for Offshore Jack-up Platform Rack Steel Manufacturing Process

Offshore jack-up platform rack steel must exhibit high strength and toughness as well as excellent welding properties.A high-quality large ingot is a prerequisite for obtaining a high-performance rough part.The electroslag remelting withdrawing(ESRW)technology using a T-shaped mold and bifilar mode was introduced to replace casting technology.Numerical simulation of the ESRW process was performed to determine the distribution of the temperature and velocity fields and to determine the optimum process for producing rack steels.Several A514 Qslab ingots with dimensions of 0.32m×1.40m×4.00 m were produced using ESRW technology in an industrial plant.The industrial test indicated that slab ingots produced by the ESRW method exhibited uniform chemical compositions and compact macrostructures.A 115.4mm thick plate was produced from the rough ingot after 11 rolling passes.Samples were obtained from different positions in the steel plate to test the mechanical performance and examine the microstructure,and the results revealed that the properties of the steel plate satisfied ASTM standards.The ESRW process improved the tensile strength and toughness of the slab ingot,enabling significant improvements in the anisotropy and low temperature toughness,which are critical for the development of rack steel for offshore platforms.     

核电站用SA738Gr.B钢板热处理工艺研究

为满足SA738Gr.B核电站用钢较高的性能要求,在实验室试验的基础上,研究了工业化生产热处理工艺参数对钢显微组织和力学性能的影响。结果表明,钢板淬火时冷却速度5℃/s时,能够避免先共析铁素体的析出;淬火温度较高时,钢板具有更细小和均匀的板条贝氏体;随着淬火加热的保温时间延长,晶粒组织粗化且铁素体含量减少;随着回火温度的升高,晶粒粗化,同时贝氏体含量减少,铁素体含量增多;在工业化生产中,较大淬火水量下钢板的拉伸性能更优;随着回火时间的延长,钢板强度下降而冲击韧性提高。以920℃×2.0 min/mm加热、较高水量的Q2工艺淬火,并采用650℃×1.5min/mm的工艺回火,可使钢板的强韧性达到最佳匹配。     

Development of High Deformation X70 Pipeline Steel Plates in NISCO

A series of trial tests for high deformation (HD) X70 pipeline steel plates were performed in NISCO,and the technical routes as thermal mechanical controlled rolling process (TMCP),TMCP + Quenching (Q) and TMCP +Q & tempering (T) were studied systematically through the plate shape quality,properties and microstructure characters.The results show that problems as plate shape and inhomogeneous microstructures are for finish rolling at low temperature and high cooling rate after the rolling by the route of TMCP.By the route of TMCP+Q,the yield strength (YS) of the trial steels is not sufficient.By the route of TMCP+QT,the YS is enhanced,as well as good toughness and plasticity due to the martensite decomposition at low temperature tempering process,and 4 sheets of HD X70 pipeline steel plates by the route TMCP+QT with superior plate shape quality,microstructure and comprehensive properties were successfully developed in NISCO.     

Development of JG785E High Strength High Toughness Steel Plates

A high strength structure steel plate --brand JG785E, which with more than 690MPa yield strength ,more than 47 joules toughness at minus 40℃ has been developed by Jigang of Shandong Steel Group P. R. China. The steel plates can be easily welded in engineering structure due to its lower carbon equivalent value. The maximum thickness of heavy plate is 50.88mm (2 inch), the yield strength is 710-860MPa, the toughness of steel plate is 139~336J at the temperature of - 40℃ . The microstructure of steel plate is lower carbon Bainite. The main solid dissolve elements are silicon and manganese. All parameters of reheating, rolling and accelerating cooling are controlled strictly. This TMCP procedure can ensure to get better mechanical properties of steel plates, and to keep the market competitive power and lower cost of manufacture. The cleanness of steel is high by refined in ladle furnace (LF), the contents of P and S is lower. It is the low carbon Bainite microstructure that possesses the high strength, excellent lower temperature toughness and better weld-ability without preheat process. The JG785E is typical brand of the Jigang’s high strength steel brands as the S690QL conforms to EN10025-6 and as the ASTM A514M conforms to USA quenching and tempering steel specification.     

屈服强度785 MPa低碳含铜船板钢的组织和性能

 研究了一种屈服强度大于785 MPa的船板钢,测试了其动态连续冷却相变曲线（CCT）,研究了试验钢经控制轧制+直接淬火+回火（DQ- T）工艺处理后的组织性能。结果表明,直接淬火（DQ）钢板组织为板条马氏体（LM）,回火后铜、铌元素呈弥散析出。经500 ℃回火钢板的强度最高,冲击韧性（KV2）最低。钢板经710 ℃回火,其组织为二次马氏体（SLM）+铁素体,屈服强度（Re）为810 MPa,抗拉强度（Rm）为 1 066 MPa,伸长率（A）为17%,在-80 ℃下KV2为97 J,达到最佳强韧性匹配。     

调质高强度压力容器钢板A517GrB的研制

介绍了济钢采用微合金化设计、控轧、调质等工艺开发的高强度压力容器钢A517GrB。通过光学显微镜、透射电镜观察分析等实验手段,研究了回火温度对力学性能和组织的影响,结果表明:随回火温度的升高,组织发生相变、回复、再结晶、碳化物析出等过程,钢板的强度降低,韧性提高。最佳回火温度为670℃。     

Study on Heat Treatment Process of AB/EQ56 Steel Plate

The article mainly describes the development process of AB/EQ56 steel plate for ocean engineering with thickness ≤50mm in Wuyang Iron and Steel Co.,Ltd.(Wugang),and studies the chemical analysis,metallographic structure,tensile strength and serial temperatures impact toughness of the steel plate.The results show that a good match of strength and toughness of AB/EQ56 steel plate with thickness ranging from 12mm to 95mm produced by ultra low alloying component control,controlled rolling and controlled cooling,proper quenching and tempering process,of which the properties are all conforming to the requirements of ABS rules.The steel plate has passed the certification of ABS and is qualified for production.More than 7000 tons of such steel plate have been ordered,which mainly apply for the cantilever beam of offshore oil platform.