TMCP工艺生产40mm厚700MPa级低碳贝氏体钢试验研究

介绍了微合金化结合TMCP+回火工艺生产40 mm 700 MPa级低碳贝氏体钢的实验过程。通过对40 mm厚700 MPa级低碳贝氏体钢合理的成分、工艺设计和关键工艺控制的研究分析,制定合理的TMCP+回火工艺,成功开发出40 mm厚规格700 MPa级低碳贝氏体钢。     

采用TMCP工艺生产700MPa级低碳贝氏体钢

以微合金化结合控轧、控冷工艺生产非热处理高强度钢,本文通过对700MPa级低碳贝氏体钢轧制工艺的研制分析,制定合理的轧制工艺,成功开发出TMCP工艺下700MPa级低碳贝氏体钢     

水电用高强度压力钢管用钢的研制开发

介绍了首钢采用TMCP＋回火工艺成功生产出SG610CFD水电用高强钢的研制开发过程。SG610CFD水电用高强钢采用铌、钒和钛复合处理,钢板回火后屈服强度为570～590MPa、抗拉强度为670～700MPa、-20℃低温横向冲击吸收功均大于200J。钢板成分设计和工艺路线合理、性能优异。     

结构件用590MPa级冷轧双相钢研发与应用

随着汽车轻量化的发展需求,为满足车身安全、环保要求,基于包钢先进的设备和工艺特点,通过C-Mn-Cr合金体系的化学成分设计,配合合理的热轧、酸轧和连续退火工艺,成功研发了汽车结构件用590 MPa级冷轧双相钢.批量生产和用户应用情况表明,冷轧双相钢HC340/590DP各项力学性能指标满足技术要求及用户使用需求.     

中锰钢在690 MPa级高强韧海洋平台中的应用探索

介绍了国内外690 MPa级海洋平台用钢的研究现状及发展趋势,对传统690 MPa级海洋平台用钢的成分、工艺、组织和性能进行了分析。传统690 MPa级海洋平台用钢主要存在成本高、制备工序复杂、组织均匀性差、屈强比高等诸多问题。采用低碳中锰的成分设计思路,配合合适的轧制和热处理工艺,成功开发出屈服强度690 MPa级高强韧海洋平台用中锰钢板,并详细阐述了690 MPa级高强韧海洋平台用中锰钢的强韧化机理。     

钢棉纤维用热轧盘条的开发生产实践

通过优化设计钢棉钢的化学成分,合理制定冶炼、连铸、控轧控冷工艺中各项关键控制参数,成功开发了钢纤维用钢。产品实物质量检验表明,钢材铁素体组织含量平均达到91%;晶粒细小,晶粒度8~9级;成分控制较好、组织均匀、力学性能稳定,抗拉强度值390~420 MPa,断面收缩率达到74.5%以上,满足了钢棉纤维用钢标准及客户使用要求。     

KD级抽油杆用钢3130的开发生产

KD级抽油杆用钢3130是兼顾强度和耐腐蚀性能的新型抽油杆用钢,根据产品的服役条件和技术协议要求,设计了钢种的化学成分和生产工艺,通过控制S、P、H等杂质元素含量,控制轧制,试验确定合理的热处理工艺,巨能特钢成功开发了KD级抽油杆用3130钢。产品组织均匀,晶粒度5级以上,各类夹杂物≤1.5级,屈服强度≥795 MPa,抗拉强度≥865MPa,伸长率≥15%,冲击功≥60 J,各项性能指标满足用户要求。     

承钢钒微合金化汽车大梁钢C610L的开发

针对承钢自身钒钛资源的优势,采用单一钒作为微合金化元素,通过合理的成分设计及工艺控制,成功开发出610MPa级汽车大梁用钢。试验结果表明:该钢板的综合性能优良,能够满足用户使用需求。     

600 MPa级热轧双相钢的研制与开发

为了满足汽车制造轻量化的行业需求,针对微合金化作用及控轧控冷工艺对双相钢组织和性能的影响展开研究,成功开发抗拉强度600 MPa级的热轧双相钢。生产实践表明,采用低C-Mn钢添加微合金元素Nb、Ti、Cr的成分优化设计,并结合控轧控冷工艺,所生产的600 MPa级热轧双相钢具有铁素体和马氏体两相组织结构,各项力学性能满足汽车用600 MPa级热轧双相钢要求。     

汽车用500 MPa级冷轧双相钢的生产实践

为了满足汽车制造业对500 MPa级冷轧双相钢汽车板的需求,河钢邯钢基于现有的高氢快冷设备和工艺特点,设计了一种C-Si-Mn成分体系,通过匹配合适的热轧和冷轧工艺,成功开发了低成本汽车用高强度冷轧双相钢HC300/500DP。试生产和用户使用结果表明,高强度冷轧双相钢HC300/500DP各项性能均满足相关标准要求和用户使用要求。     

Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel

 Friction welding is a solid state joining process used extensively currently owing to its advantages such as low heat input, high production efficiency, ease of manufacture, and environment friendliness. Materials difficult to be welded by fusion welding processes can be successfully welded by friction welding. An attempt was made to develop an empirical relationship to predict the tensile strength of friction welded AISI 1040 grade medium carbon steel and AISI 304 austenitic stainless steel, incorporating the process parameters such as friction pressure, forging pressure, friction time and forging time, which have great influence on strength of the joints. Response surface methodology was applied to optimize the friction welding process parameters to attain maximum tensile strength of the joint. The maximum tensile strength of 543 MPa could be obtained for the joints fabricated under the welding conditions of friction pressure of 90 MPa, forging pressure of 90 MPa, friction time of 6 s and forging time of 6 s.     

大热输入焊接材料的研究开发现状

阐述了大热输入焊接对焊缝金属组织和力学性能的影响,分别介绍了590和780MPa以上级别焊接材料的不同韧化机制。列举了日本现有超大热输入电渣焊焊接材料开发实例中,通过改变焊剂碱度以调整氧化物粒子数量并使其在850～1000kJ/cm的焊接热输入条件下,仍能得到针状铁素体组织并使0℃冲击功达到123J的成功经验。指出目前中国大热输入焊接材料研究开发中存在的问题和今后的发展方向。     

700MPa级高强度调质钢板焊接性能研究

从低成本700 MPa级调质中厚钢板的焊接性能着手,分析了母材的成分、组织及性能特点,研究了其焊接冷裂纹敏感性、焊接过程中的热输入量以及焊后热处理过程对试验钢焊接接头组织和性能的影响。结果表明,针对50 mm厚的700 MPa级高强度调质钢板,在中等拘束条件下,采用BHG-4M焊丝富氩混合气体保护焊、预热100℃的工艺进行焊接可以防止冷裂纹产生;在苛刻拘束条件下,最低预热温度在120℃以上才能防止裂纹产生;试验钢对焊接工艺规范有较强的适应性,焊接热输入量在8.85~24.17 kJ/cm范围内变化时,试验钢焊接接头的综合力学性能保持在较高水平。     

Influence of welding heat input on the HAZ of hot-rolled high strength steel

When welding the hot-rolled high strength steel manufacture by thermal-mechanical controlled process（TMCP）,there has a soften zone in the heat affected zone（HAZ）.Evaluate the welding quality though the research on the influence of softened zone’s width,hardness,strength by the different heat input. Take the 8mm thickness QSTE700TM that produced by Baosteel as an example and used the gas metal arc welding（GMAW,the CO₂ and Ar as the shield gas） welding method choose the high strength welding wire ER76-G（GB）、ER110S-G（AWS） as the welding consumer.Adjust the welding heat input range from 6.8 kJ/cm to 43.6 kJ/cm and found that as the heat input increased the tensile strength,fatigue strength of the welding structure and the hardness of the HAZ will decreased.But when using the lower heat input the quality of the welding structure can fulfil the usage request splendidly.And give the advise to increased the welding quality in detail:when keep the heat input in the scope of Q =6.8 -20 kJ/cm the good welding quality can be achieved successful.And the further research approve that when usage the lower strength welding consumer such as the ER50-6（GB）、ER70S-G（AWS） the welding structure can also achieved high quality for which the tensile strength can get about 700 MPa when use the lower welding heat input.Thus not only keep the welding quality,but also decreased the cost.     

优质大线能量焊接用高强船板的开发

船舶制造为了提高效率采取了增加焊接线能量手段,针对提高大线能量焊接热影响区(HAZ)的韧性,开发了JFE EWEL新技术,其核心是采用最佳TiN形态控制HAZ区的晶内组织状态、微合金化技术控制HAZ区域的组织结构及超级OLAC和工艺参数优化组合。基于本技术开发生产的390MPa厚板、LPG船用低温钢、355MPa船板,其优良的母材特性满足了大线能量焊接等要求。     

大线能量焊接用EH420海工钢生产工艺及焊接性能

河钢集团有限公司开发了利用钢液中形成TiO_x?MgO?CaO细小粒子改善焊接粗晶热影响区韧性的ITFFP技术（Improve the toughness of HAZ by forming TiO_x?MgO?CaO fine particles in steel）,成功试制生产出大线能量焊接用30 mm厚度规格（H30）和60 mm厚度规格（H60）EH420海洋工程用钢。母材力学性能试验结果表明,H30和H60试制钢屈服强度分别达到461 MPa和534 MPa,抗拉强度分别达到570 MPa和628 MPa,延伸率分别为26%和24.5%,满足EH420海洋工程用钢国家标准要求。采用Gleeble-3800型热模拟试验机对试制钢进行了200 kJ·cm?1条件下热模拟试验,并对焊接热影响区中的显微组织和?40 ℃冲击韧性进行了分析和测试。结果表明,试制钢中形成的CaO(?MgO)?Al₂O₃?TiO_x?MnS夹杂物可以有效地诱导针状铁素体析出,显著提高钢材的冲击韧性。另外,利用气电立焊设备对H30和H60试制钢分别进行了焊接线能量为247 kJ·cm?1和224 kJ·cm?1的实焊试验,结果显示,H30试制钢焊接接头表面和根部焊缝处?40 ℃冲击吸收功值≥74 J,焊接热影响区≥115 J,H60试制钢焊接接头表面和根部焊缝处?40 ℃冲击吸收功值≥91 J,焊接热影响区≥75 J,焊接接头的冲击性能远高于国家标准值42 J。      

Microstructural and Mechanical Studies of T91/T22 Welded Joints

Comparative studies have been performed to decide an appropriate combination of welding process and filler material by virtue of microstructural evolution, micro-hardness studies, tensile strength and fractographic analysis. Manual arc welding and tungsten inert gas welding processes are used along with different filler materials to manufacture T91/T22 welded joints. Studies with the purpose of comparison and evaluation of different zones of the weldments have been carried out. The highest value of micro-hardness observed on the T91 HAZ of the weldments may be attributed to martensitic structure of the region. The fracture morphology of both the weldments obtained from T22 BM has revealed the ductile fracture. Comparatively higher tensile strength (578 MPa) of T91/T22, GTAW combination is noticed by virtue of lower heat input. The better performance of T91/T22, GTAW weldment can be quoted on the basis of better joint integrity, tensile strength and ductility (26.4%).     

大型原油储罐用高强钢焊接性能研究

采用实物焊接和热模拟的方法研究了大型原油储罐用610MPa级高强度钢板大热输入焊接性能。结果表明,试验钢具有良好的抗大热输入量焊接的能力,原因是钢板中存在大量细小、弥散分布的TiN复合粒子,在焊接热循环的高温阶段,TiN粒子通过有效钉轧奥氏体晶界和促进铁素体晶内形核,抑制了焊接热影响区组织粗化;采用气电立焊和埋弧横焊焊接后,焊接对接接头的拉伸强度、低温冲击和冷弯性能优良,性能指标富余量大,试验钢板完全可以应用于10万m3及以上大型石油储罐的建造。     

含硼低合金高强度钢焊接热影响区冲击韧度

利用Gleeble热模拟机对含硼低合金高强度钢板进行不同焊接工艺下的热模拟实验,研究了焊接热影响区(HAZ)的过热区显微组织、韧度及其变化规律.结果表明:钢板过热区冲击韧度随冷却时间t_8/3的增大而显著降低;当t_8/3小于67s时,过热区冲击韧度较高,相应过热区组织为板条马氏体或板条马氏体+贝氏体,晶粒较细小.800MPa级低碳贝氏体钢板焊接工艺实验结果表明,焊接热输入量为0.96~2.11kJ·mm^-1、焊道间温度为150~200℃和焊后热处理,焊接接头焊缝金属和焊接热影响区的冲击韧度保持较高水平,说明钢板对焊接工艺有较强的适应性.     

Laboratory development of high performance steel plates with excellent HAZ toughness at large heat inputs

Presented in this study is the result of steel plates developed at laboratory by using the technique of chemistry design based on microstructure evolution.It has been shown that the produced 50mm thickness steel plates with yield and tensile strength being 420 MPa and 530 MPa respectively exhibit excellent large heat input weldability:the Charpy impact tests in the whole range of heat affected zone(HAZ) including the fusion line at the welded joint with large heat input of 100 -300 kJ/cm showed uniform impact toughness of above 140 J at -40℃.Welding simulations were also performed for heat inputs of 200-600 kJ/cm,which showed far better toughness at -20℃.Analysis on the results of the simulations and the practical welding tests were done and the microstructure evolution mechanisms were proposed.Finally suggestions were given to improve the simulation processes as well as chemistry modification.