共查询到19条相似文献,搜索用时 46 毫秒
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采用 OM 和 SEM 对 700 MPa 级高强度大梁钢冲压开裂原因进行了分析。结果表明,在高强度大梁钢冲压过程中出现的纵梁穿线孔裂纹主要为连冲工艺不当导致;纵梁端部折弯角部裂纹主要是由于原板坯存在内裂纹和大尺寸 TiN 夹杂物,在冲压过程中外表面受到拉应力产生裂纹,裂纹沿横纵向扩展导致。通过将钛质量分数由 0.10% 降至 0.07%,将氮质量分数控制在不大于 0.004% 的范围内,降低大尺寸TiN析出量。化学成分调整后,力学性能满足供货技术条件要求,对钢板进行冲压验证,端部完好,未见折弯裂纹存在,彻底解决了该缺陷。 相似文献
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通过设计合理的化学成分,采用铁水预处理→120t转炉→LF精炼→FTSR(Flexible Thin Slab Rolling,灵活的薄板坯连铸连轧)连铸机(87.5mm厚薄板坯)→2机架粗轧+5机架精轧→卷取工艺流程,借助全流程TMCP(Themlo Mechanical Control Process,热机械控制工艺),成功生产了61(IMPa级汽车大梁钢。检验结果表明:钢板组织为铁素体+贝氏体+少量马氏体和残余奥氏体组元,晶粒尺寸2.08μm;板卷各项力学性能均能满足要求。对冲击断口做扫描电镜发现,冲击断口为韧性断口,且韧窝底部有球形CaS质点。 相似文献
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介绍了安钢1780 mm热连轧机组开发700 MPa级别高Ti汽车用钢的开发,及生产工艺和质量情况。通过试验证明,安钢1780 mm热连轧生产的700 MPa级的高Ti钢具有良好的强韧性配合,优良的成型性能,经用户使用后,完全满足汽车生产工艺的要求。 相似文献
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薄规格高强钢以其强度高、轻量化的优势一直受到了汽车市场的广泛关注,但其加工过程易受载荷、环境温度的影响而发生断裂失效。针对热轧700 MPa级别薄规格高强钢材料在制管剪切过程中出现的开裂问题进行了全流程系统剖析。对其冶金缺陷、晶粒及晶界缺陷、夹杂物控制、金相组织缺陷、元素偏析、零件加工缺陷、冷加工缺陷及脆性显微组织缺陷等可能的成因进行了逐项分析,最终认为材料在冷加工中产生的端部毛刺是高强钢开裂的根本原因。建议用户定期更换剪刃,尤其在钢管端部出现毛刺等缺陷时需尽快更换。 相似文献
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设计和开发了屈服强度750 MPa低合金高强度集装箱用钢(/%:0.06~0.09C,0.25~0.35Si,1.60~1.80Mn, ≤0.015P,≤0.003S,0.10~0.20Mo,0.05~0.06Nb,0.09~0.11Ti,≥0.0015Ca,≥0.015Alt)。试验钢的工艺流程为260 t BOF-LF-RH-230 mm板坯连铸-热轧成2~6 mm板。通过Nb-Ti复合微合金化和Ca处理,控制精轧结束温度840~880℃,层流冷却速度≥60℃/s,卷取520~580℃,热轧钢卷的冷却速度≤10℃/h等工艺措施,热轧带钢具有良好的表面质量,组织为细晶铁素体+Nb-Ti碳氮化物,力学性能为上屈服强度760~790 MPa,抗拉强度860~910 MPa,伸长率21%~25%,满足用户要求。 相似文献
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The microstructural evolution in a 700 MPa hot rolled high strength steel was analyzed in terms of strengthening mechanisms.The results show that the hot rolled sheet steel has yield strength of 710 MPa with good elongation and toughness.The strength of the developed 700 MPa hot rolled high strength steel is derived from the cumulative contribution of fine grain size,dislocation hardening and precipitation hardening.The fine grain strengthening and precipitation hardening are the dominant factors responsible for such high strength,and the amount of precipitation hardening is two or four times higher than that of conventional microalloyed hot rolled sheet steels reported in the past.Good toughness is due to refinement of ferrite grain size. 相似文献
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《钢铁研究学报(英文版)》2011,(Z1):983-986
590 MPa automobile beam steel strips are used mainly to manufacture the longitudinal beam of trucks.It’s welding properties are critical to the safety of truck.The microstructure and mechanical properties of welding joints processed by CO 2 arc welding with different welding parameters were studied.The results showed that the welding joints were weak when welding heat input were small and the non metal inclusions were found in the weld joints when welding heat input are big.The quality of the welding joints is good enough at 170A of the arc current and 24V of the arc voltage.Keeping the other welding parameters fixed,the incomplete fusion defect occurred in the welding joint with backward welding,but the quality of the welding joint is good with forward welding. 相似文献
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开发的Nb-Ti微合金高强钢(/%:0.04C、0.34Si、1.40Mn、0.010P、0.004S、0.098Nb、0.020Ti、0.045Al、0.002 5N)由真空感应炉冶炼、50 kg钢锭40 mm锻造板坯经试验室单架轧机于1 200℃7道次轧制成10mm板,末道次压缩比≥15%,终轧温度880℃,喷水冷却至600℃,置于热处理炉600℃30 min,炉冷至室温,分别模拟层流冷却和卷取工艺。该钢经Gleeble 3500热模拟机试验得出,高温低塑性区为650~800℃和≥1 300℃。力学性能试验结果为下屈服强度Rel625~640 MPa,抗拉强度Rm705~710 MPa,伸长率18.0%~19.5%。所开发的钢具有碳当量低,焊接性能好,成本低等特点。 相似文献
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A high strength steel with yield strength on the order of 600 MPa was developed successfully with only addition of titanium alloying element based on a low-carbon steel.The results showed that the hot deformation accelerated ferrite and pearlite transformation and retarded bainite transformation under continuous cooling condition.The microstructure of this steel was mainly composed of fine grained ferrite and carbides distributing along the ferrite grain boundaries.The yield and tensile strengths of steels ... 相似文献
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