铸态超级双相不锈钢S32750热加工性能

 为研究热变形参数对铸态超级双相不锈钢S32750热变形行为和显微组织的影响,运用Gleeble-3800热模拟试验机对S32750进行不同温度和应变速率下的高温拉伸和压缩试验。结果表明,S32750在1000~1200℃范围内具有较好的热塑性。在变形温度较低、应变速率较低时,流变曲线表现出不同于单相不锈钢的“类屈服平台”特征;当应变速率较高或变形温度较高、应变速率较低时,流变曲线为典型的动态再结晶特征。微观组织演变显示,铁素体和奥氏体两相都发生动态再结晶,且铁素体的再结晶先于奥氏体。降低应变速率,提高变形温度,可促进动态再结晶发生。基于热变形动力学模型建立了本构方程,表观应力指数为3.99,热变形激活能为393.75kJ/mol。S32750的高温软化机制与Zener-Hollomon(Z)参数有关,随Z参数增加,热变形峰值应力增加。     

双相不锈钢2205铸态组织的热变形研究

研究了工业连铸双相不锈钢2205在不同温度和应变速率下的热变形过程。通过单道次热模拟压缩试验分析了铸态2205流变应力与温度和应变速率的关系,计算出铸态2205的热变形激活能Q=599 kJ/mol,说明铸态2205热加工性能较差。组织分析显示,两相之间变形不协调是相界微裂纹产生的根本原因。     

热等静压UNS S32750超级双相不锈钢的组织和性能

采用等离子旋转电极雾化-热等静压工艺制备了UNS S32750超级双相不锈钢。利用光学显微镜、扫描电子显微镜、电子背散射衍射、万能试验机等手段研究了热等静压UNS S32750超级双相不锈钢固溶处理前后的显微组织和力学性能。结果表明:采用等离子旋转电极雾化制备的UNS S32750超级双相不锈钢粉末在150 MPa 压力下,经1200 ℃×3 h热等静压烧结后实现了致密化,相对密度为99.7%。随炉缓冷过程中,烧结件中析出的σ相导致材料韧性显著下降。经1035 ℃×1 h固溶处理后水淬,σ相完全溶解,材料韧性显著提高,显微组织为α和γ两相组织,体积比为65:35,抗拉强度791 MPa,屈服强度586 MPa,断后伸长率38%,冲击吸收功236 J。     

太钢成功开发S32750超级双相不锈钢

日前，太钢超级双相不锈钢S32750中板开发成功，成为国内首家成功生产超级双相不锈钢的企业。     

太钢成功开发S32750超级双相不锈钢

日前，与太钢新不锈钢工程配套的焦化项目煤调湿干燥机主体不锈钢板材的自主研制取得重大突破，超级双相不锈钢S32750中板开发成功，成为国内首家成功生产超级双楣不锈钢的企业。     

2507超级双相不锈钢的热变形行为

用MMS-200热模拟实验机对2507超级双相不锈钢(/%:0.022C、0.58Si、25.35Cr、7.17Ni、4.05Mo、0.28N)12 mm热轧板在1 000～1150℃、应变速率0.01～10s^-1下进行了热压缩实验。实验结果表明,在应变速率一定的条件下,变形温度越高,2507超级双相不锈钢峰值应力越低;在变形温度一定的条件下,峰值应力随着应变速率的增加而增加。根据热变形方程计算得到压缩变形时的平均表观应力指数n=3.25,热变形激活能Q=460kJ/mol。基于实验数据构建了2507超级双相不锈钢在相应变形条件下的热变形方程。     

攀钢成功开发超级双相不锈钢S32750挤压管

攀钢集团攀长钢公司成功开发出超级双相不锈钢S32750挤压管,填补国内空白。这是该公司自2007年研制出超级双相不锈钢S32750以来取得的又一重大突破,也使攀长钢成为国内首家生产此钢种管材的企业。S32750产品适用于石油化工、真空制盐、烟气脱硫等具有高腐蚀环境的领域,目前在世界上只有少数国家可以生产,国内一直依靠进口,价格昂贵且周期长。该产品开发成功后,攀长钢已形成了S32750、S31803等不同级别双相不锈钢管材的产品系列。     

太钢双相不锈钢S32750介绍

与太钢新不锈钢工程配套的焦化项目煤调湿干燥机主体不锈钢板材的自主研制取得重大突破，超级双相不锈钢S32750中板开发成功，成为国内首家成功生产超级双相不锈钢的企业。     

固溶处理对超级双相不锈钢S32750组织和性能的影响

研究了950～1 200℃60 min水冷的固溶处理对超级双相不锈钢S32750(/%:0.02C、0.49Si、1.03Mn、0.026S、0.001P、25.01 Cr、7.03Ni、3.80Mo、0.29N)12 mm板的组织、力学性能和耐蚀性的影响。结果表明,随固溶温度升高,钢中铁素体相增加,奥氏体相减少;在950℃加热时铁素体中析出大量σ-相,使钢的性能恶化,在1 050～1 100℃固溶处理后,钢中铁素体相和奥氏体相各占50%, S32750钢具有较好的综合力学性能和优良的耐蚀性能。     

超级双相不锈钢S32750板材的冶炼工艺研究

介绍了00Cr25Ni7Mo4N在冶炼过程中高N含量控制工艺和钢质纯净度控制工艺。通过确定合理的控N及吹Ar参数,实现精确N含量控制;通过进行Al、Si-Ca及稀土强化脱硫脱氧,保证了良好的钢质纯净度。     

Hot Deformation Behavior of As-Cast 2101 Grade Lean Duplex Stainless Steel and the Associated Changes in Microstructure and Crystallographic Texture

The hot deformation behavior of 2101 grade lean duplex stainless steel (DSS, containing ~5 wt pct Mn, ~0.2 wt pct N, and ~1.4 wt pct Ni) and associated microstructural changes within δ-ferrite and austenite (γ) phases were investigated by hot-compression testing in a GLEEBLE 3500 simulator over a range of deformation temperatures, T _def [1073 K to 1373 K (800 °C to 1100 °C)], and applied strains, ε (0.25 to 0.80), at a constant true strain rate of 1/s. The microstructural softening inside γ was dictated by discontinuous dynamic recrystallization (DDRX) at a higher T _def [1273 K to 1373 K (1000 °C to 1100 °C)], while the same was dictated by continuous dynamic recrystallization (CDRX) at a lower T _def (1173 K (900 °C)]. Dynamic recovery (DRV) and CDRX dominated the softening inside δ-ferrite at T _def ≥ 1173 K (900 °C). The dynamic recrystallization (DRX) inside δ and γ could not take place upon deformation at 1073 K (800 °C). The average flow stress level increased 2 to 3 times as the T _def dropped from 1273 to 1173 K (1000 °C to 900 °C) and finally to 1073 K (800 °C). The average microhardness values taken from δ-ferrite and γ regions of the deformed samples showed a different trend. At T _def of 1373 K (1100 °C), microhardness decreased with the increase in strain, while at T _def of 1173 K (900 °C), microhardness increased with the increase in strain. The microstructural changes and hardness variation within individual phases of hot-deformed samples are explained in view of the chemical composition of the steel and deformation parameters (T _def and ε).

     

固溶温度对超级双相不锈钢S32750板材组织和耐蚀性的影响

研究了920～1100℃固溶处理温度对S32750钢中板(%:0.022C、25.35Cr、7.17 Ni、4.05Mo、0.28N)组织和6%FeCl₃+0.05NHCl溶液耐蚀性的影响。结果表明,≤1000℃固溶处理时,钢中析出脆性σ-相,铁素体含量≤11%,钢的硬度增加,钢的塑性、韧性和耐蚀性急剧下降,于1050～1100℃固溶处理,钢中组织为46%～47%铁素体+奥氏体组织,具有良好的综合力学性能和高的耐蚀性。     

Effects of Temperature and Strain Rate on Flow Behavior and Microstructural Evolution of Super Duplex Stainless Steel under Hot Deformation

Hot compression tests were carried out in the temperature range of 1 223-1 473 Kand strain rate range of0.01-30s-1 to investigate the flow behavior and microstructural evolution of super duplex stainless steel 2507(SDSS2507).It is found that most of the flow curves exhibit a characteristic of dynamic recrystallization(DRX)and the flow stress increases with the decrease of temperature and the increase of strain rate.The apparent activation energy Qof SDSS2507 with varying true strain and strain rate is determined.As the strain increases,the value of Qdeclines in different ways with varying strain rate.The microstructural evolution characteristics and the strain partition between the two constituent phases are significantly affected by the Zener-Hollomon parameter(Z).At a lower lnZ,dynamic recovery(DRV)and continuous dynamic recrystallization(CDRX)of the ferrite dominate the softening mechanism during the compression.At this time,steady state deformation takes place at the last stage of deformation.In contrast,a higher lnZ will facilitate the plastic deformation of the austenite and then activate the discontinuous dynamic recrystallization(DDRX)of the austenite,which leads to a continuous decline of the flow stress even at the last deformation stage together with CDRX of the ferrite.