共查询到19条相似文献,搜索用时 140 毫秒
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1 前言本文对 0 8Cr2 Mn2 V和 0 8Cr2 Mn2 Nb高强度钢进行了研究。对这些钢进行空淬可得到马氏体—贝氏体组织 ,其断面尺寸可达 3 0 0 mm厚 ,无论是热轧还是淬硬钢在零度以下都具有高强度 (σb>70 0 MPa)和高的冲击韧性 ,并把马氏体 -贝氏体复合组织性能与马氏体 贝氏体的组织性能进行了对比研究。热循环用于细化组织并提高马氏体 -贝氏体钢的机械性能 ,同时也建立了热循环状态下 TTT及超细晶粒奥氏体的动力转变曲线。为了得到表面硬化 ,采用了电子束处理技术 ,电子束处理确保淬透层深度 1 .8~ 1 .9mm,并提高了钢的显微硬度。2 低… 相似文献
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《炼钢》2017,(5)
测定了稀土脱氧和铝稀土复合脱氧钢焊接热影响区(HAZ)的连续冷却转变曲线,分析了2种钢中的夹杂物种类及其HAZ的显微组织和常温冲击韧性。得到如下结论:稀土脱氧使钢中主要夹杂物从Mn S转变为RE2O2S+Mn S,而铝稀土复合脱氧钢中夹杂物主要是Ce Al O3+Ce2S3+Mn S。稀土脱氧钢HAZ中能获得晶内铁素体的冷速较宽,约为0.5~7.5℃/s。铝稀土复合脱氧钢HAZ获得晶内铁素体组织较稀土脱氧钢要困难一些,适合晶内铁素体形成的冷速变窄为1~3℃/s,HAZ中晶内铁素体的含量明显低于稀土处理钢,Al脱氧弱化了稀土处理对钢HAZ组织的改善作用。焊接热输入线能量为100 k J/cm时,稀土脱氧能够明显改善钢HAZ的室温冲击韧性。 相似文献
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稀土-硼对30CrMn2Si马氏体铸钢性能和组织的影响 总被引:4,自引:0,他引:4
本文研究了稀土-硼复合变质剂对30CrMn2Si马氏体铸钢的组织转变、性能及夹杂的影响。结果表明;稀土-硼复合变质处理能细化组织,减缓奥氏体分解,提高钢的淬透性,使Ms点升高,并抑李晶马氏体形成,增加位错马氏体比例,改善夹杂物形态、大小及分布:从而使该钢的αK提高70%,δs提高65%,α2、αb均提高200MPa以上。 相似文献
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采用传统的高强钢焊接材料焊接690 MPa级低碳铜沉淀强化钢时,仍需严格控制热输入、预热温度、层间温度,这使得低碳铜沉淀强化钢的优良性能和可节约生产成本的优势得不到很好地发挥。通过采用光学显微镜(OM)、扫描电子显微镜(SEM)、透射电镜(TEM)等表征方法,研究了不同质量分数的Si/Mn/Ni配比对690 MPa级超低碳贝氏体(ULCB)熔敷金属的组织及强韧性能的影响,为690 MPa级低碳铜沉淀强化钢配套的焊接材料的工程化应用提供一定的技术支持和积累。结果表明,690 MPa级超低碳贝氏体(ULCB)熔敷金属组织主要由板条贝氏体、粒状贝氏体和针状铁素体组成。当Si质量分数为0.16%、Mn质量分数为1.46%时,熔敷金属组织细化,冲击韧性得以提升,但Si含量过低易使贝氏体铁素体呈块状,导致韧性提升有限。而当Si质量分数为0.29%、Mn质量分数为1.02%时,Ni含量增加,贝氏体铁素体板条呈细长条状,显微组织相互交错分布,使熔敷金属冲击韧性显著改善。相变位错强化受贝氏体开始转变温度(Bs)影响,这是影响ULCB熔敷金属强度的主要原因。ULCB熔敷金属中夹杂物主要分布在贝氏体铁素体的板条亚结构间,少量成为针状铁素体的形核质点,促进针状铁素体形核,因此,对熔敷金属中的夹杂物进行控制,可进一步发挥超低碳贝氏体熔敷金属的潜力,提高其韧性。 相似文献
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热锻用高强高韧非调质钢32Mn2SiV组织与性能的研究 总被引:1,自引:0,他引:1
研究了高强高韧非调质钢32Mn2SiV形变后冷却速度及二次加热对显微组织的影响,并分析了不同组织状态对冲击韧性的影响。结果表明,随加热温度增高和冷却速度增加,钢中贝氏体量增加,使韧性降低,在保持细晶组织时,少量细小粒状贝氏体的存在对钢的冲击韧性没有损害。 相似文献
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利用膨胀仪并结合金相法和硬度法,测定了新型Nb-V微合金化贝氏体钢轨钢20mm板(/%:0.24C,0.39Si,1.86Mn,0.007S,0.002P,1.36Cr,0.33 Mo,0.04Nb,0.11V)的连续冷却转变(CCT)曲线,研究冷却速度0.04~4.0℃/s对钢的显微组织及硬度的影响。结果表明,试验钢Bs点温度低于400℃,当冷却速度在0.1~0.8℃/s,试验钢可获得全贝氏体组织,符合贝氏体钢轨的合金设计原理;试验钢的轧态显微组织以板条贝氏体为主,还有少量的马氏体,其强度、塑性、韧性、硬度各指标匹配较好,满足现行贝氏体钢轨相关技术条件的要求。 相似文献
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研究了Si—Mn—Cr低碳贝氏体钢在正火和回火过程中的组织转变和性能变化。结果表明:经350℃回火后具有良好的强韧配合,新型贝氏体钢屈服强度为1 196 MPa,抗拉强度为1 437 MPa,伸长率和断面收缩率分别为13%和50%,冲击韧性为72 J/cm~2,强韧性配合明显高于普通及淬火珠光体钢轨钢。而在450℃~600℃回火时出现明显的回火脆性。通过研究回火后的组织转变及残余奥氏体热稳定性、机械稳定性的变化,探讨了无碳贝氏体韧化及脆化机理,提出了适于该钢的最佳回火工艺。 相似文献
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Effect of Rare Earth Composite Modification on Microstructure and Properties of a New Cast Hot-Work Die Steel 总被引:5,自引:0,他引:5
The effects of RE modification on structure and the properties of a new cast hot-work die (CHD) steel were investigated. The grains of the CHD steel are refined by RE modification. With the increase of RE addition, both grain size and inclusion amount are reduced. Appropriate amount of RE results in decrease in inclusion amount and formation of spheroidal inclusions uniformly - distributed in steel, so that the morphology and distribution of inclusions are improved. RE composite modification favors the formation of bainite, austenite and fine lath martensite with dense dislocation. When the residual RE content reaches 0.02 %, no obvious changes in strength and hardness are found, while fracture toughness and threshold of fatigue crack growth are increased. The impact toughness, elongation and reduction of cross sectional area are increased by a factor of two, and thermal fatigue resistance is also improved. 相似文献
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Effects of Rare Earths and Al on Structure and Performance of High Chromium Cast Iron Containing Wolfram 总被引:2,自引:1,他引:2
High chromiumcast ironis ani mportant grade ofwear-resistant material.It exhibits high hardness,ex-cellent wear resistance,andlowdeflection onrupture.Moreover,combined properties of high chromiumcastiron are better than that of other white cast irons.Therefore,it has many applications[1~4]in concrete,electric power,mine,metallurgy,and especially ap-plicationin ball mill with large diameter subjected toheavy i mpact loading[5].However,the brittle natureof this material often causesfailure under… 相似文献
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M 2highspeedsteel (M 2steel)isamaterialwidelyusedintoolsanddies[1,2 ] .M 2steelischarac terizedbyalongsolidificationrangeandcomplexeu tecticreactions ,whichresultsinsegregationofalloy ingelementsandformationofseveraldifferenttypesofcarbidesduringsolidification[3,4 ] .Forconventionallyprocessedhigh speedsteels ,itisinevitablethatacoarsecarbidenetworkwillbeformedduringsolidifi cation .Coarseprimarycarbidestendtoresultinun evencarbidebandsdistributionafterasubstantialamountofhotprocessing[5] .Ma… 相似文献
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研究了硅锰合金化贝氏体耐磨管的成型工艺,讨论了贝氏体球铁管的化学成分、组织和性能等指标,研究表明:试验成分的贝氏体耐磨管成型性能良好,热处理工艺简单,硬度高,韧性好,成本低,实用经济效益显著,为贝氏体耐磨球铁管的应用开辟了广阔的市场前景。 相似文献
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The microstructures, mechanical properties and abrasive wear behaviour of five kinds of Si‐Mn‐Cr‐B cast steels were studied. The steels investigated contained X wt.% C with X= 0.15, 0.25, 0.35, 0.45, 0.55, 2.5 wt.% Si, 2.5 wt.% Mn, 0.5 wt.% Cr, 0.004 wt.%B . The results showed that the Ac1temperatures increased and Ac3 and Ms temperatures decreased with increasing carbon concentration. From the continuous cooling transformation (CCT) curves, it was discovered that the incubation period of pearlitic transformation was prolonged and the transformation curves of pearlite and bainite were separated significantly with rising carbon concentration. At lower carbon concentration, the normalized structure of Si‐Mn‐Cr‐B cast steel consisted mainly of granular bainite and M‐A islands. The normalized microstructures of the cast steel changed from granular bainite gradually to needle‐like bainite, upper bainite, and lower bainite with rising carbon concentration. The tensile strength and hardness of Si‐Mn‐Cr‐B cast steel increased and impact and fracture toughness decreased with increasing carbon content. The wear testing results showed that the wear resistance of Si‐Mn‐Cr‐B cast steel improved with higher carbon content but was obviously unchanged beyond the carbon concentration of 0.45%. The best balance of properties of Si‐Mn‐Cr‐B cast steel is obtained at the carbon concentration range of 0.35 ‐ 0.45%C. 相似文献
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Thepoormechanicalpropertiesofcastmaterials ,especiallylowtoughness ,isamainfactorlimitingtheapplicationofprecisecastdies[1] .ThroughthemodificationofcastH1 3steelbyRE ,thedendritesegregationofCH1 3steelwasimprovedandgrainboundarycarbidewasalsoundercontrol.Acc… 相似文献