超级双相不锈钢S32760疲劳性能研究

S32760是超级双相不锈钢的代表钢种之一,具有良好的力学性能.在YRB-200旋转弯曲疲劳机上对其在空气中的疲劳性能进行了试验,结果表明S32760在空气中的疲劳极限为556.667MPa,S-N曲线的幂函数表达式为S=1055.46285-0.04136.夹渣及其造成的显微疏孔比夹杂物更容易导致双相不锈钢萌生裂纹....     

现代双相不锈钢焊接研究

在概述现代双相不锈钢的发展及有关焊接方面若干问题的基础上，采用有代表性的2205双相不锈钢进行MIG焊接试验，研究了热输入量对焊缝的金相组织、铁素体含量、硬度及冲击韧性的影响，以及混合保护气体（Ar30％He1％O2）对焊缝成形及性能的影响。此外还提出了采用计算机图象分析仪进行铁素体含量测定的方法。研究结果表明，2205双相不锈钢具有良好的可焊性，采用MIG焊在不同的规范下均可以获得性能优异的焊缝；混合保护气较纯氩保护时可以获得更大的熔深和更好的焊缝形状；计算机图象分析可以更迅速、精确地测定铁素体含量，且重复性好。     

焊接对超级奥氏体不锈钢UNS08367耐腐蚀性的影响

超级奥氏体不锈钢凭借其优异的耐CL-腐蚀性能近年来被广泛应用。通过对UNS08367焊缝及热影响区焊态以及固熔处理态耐点蚀和耐缝隙腐蚀试验,分析焊接对UNS08367耐腐蚀性能的影响。     

双相不锈钢薄壁管的焊接工艺

论述了双相不锈钢薄壁管焊接面临的问题,提出了相应的焊接工艺制定的原则.结合施工实例,制定了具体的焊接工艺参数,并在实用中进行了试验验证.     

超级双相不锈钢电化学腐蚀性能的实验研究

利用电化学工作站,对SAF2906超级双相不锈钢的耐点蚀性能、耐晶间腐蚀性能进行了研究。结果表明:SAF2906在3.5 wt Na Cl溶液中,具有比较宽的钝化区,以及较小的腐蚀电流密度(0.147μA·cm-2),耐点蚀性能良好;在2 mol/L H2SO4+1 mol/L HCl介质中,具有较低的再活化率(4.39),其晶间腐蚀敏感性较小,具有良好的耐晶间腐蚀性能。     

双相钢不锈钢药芯焊丝堆焊试验

双相不锈钢在室温下固溶体中奥氏体和铁素体约各占半且兼有两相组织特征。它保留了铁素体不锈钢导热系数大、线膨胀系数小、耐点蚀,缝蚀及氯化物应力腐蚀性能的特点;又具备奥氏体钢不锈钢韧性好、脆性转变温度较低、抗晶间腐蚀、力学性能和焊接性能好的优点,双相不锈钢堆焊层的力学性能和耐蚀性取决于接头能否保持适当的相比例,正确选用焊接材料、严格控制焊接热输入量以及制定合理的焊接工艺是是双相不锈钢焊接的关键,本文进行了双相不锈钢药芯焊丝堆焊工艺试验、焊接工艺评定及产品的施焊,各项技术指标均满足要求,证明所选用的焊接方法、焊接材料、焊接工艺规范正确合理。     

核电用S32101双相不锈钢的焊接性研究

双相不锈钢S32101广泛应用于AP1000三代核电楼板结构模块抗腐蚀内壁板,本文对双相钢焊接性进行了研究,分析了不同线能量条件下接头性能的变化,尤其是冲击韧性的变化。     

SAF2205双相不锈钢焊接工艺及耐蚀性的研究

本试验以获得合理的奥氏体/铁素体两相比例为指导原则,采用6组焊接工艺参数对2205双相不锈钢板材进行对接。首先对各个焊接接头进行定量金相计算及分析,然后通过拉伸、弯曲试验选取力学性能优良的焊接接头进行腐蚀试验。焊缝的耐蚀性因其焊缝中奥氏体含量区别不大而无太大差异,腐蚀介质浓度较高时,在保护气中加入2%的氮气,试样耐蚀性较强,但3组试样的焊接接头焊缝的耐蚀性均小于母材。     

S32750超级双相不锈钢的热变形及组织分析

利用MMS-200热模拟实验机,对S32750超级双相不锈钢在温度为1 000～1 150℃,应变速率为0.01～10 s-1的条件下进行了单道次压缩实验,测定了真应力-真应变曲线,对热变形组织进行了分析.实验结果表明:当变形温度一定时,峰值应力随着应变速率的增加而增加.提高热变形温度,降低应变速率,可以促进奥氏体动态再结晶的发生.根据热变形方程计算得到压缩变形时的热变形激活能Q=460 kJ/mol.在相应的变形条件下,获得了S32750超级双相不锈钢热变形过程中峰值应力与Z参数的关系式.     

光束焦点位置对双相不锈钢光纤激光#br#焊接焊缝成形和组织的影响

通过焊接热模拟方法和现代材料组织分析技术,研究了光束焦点位置对于双相不锈钢2205光纤激光焊接焊缝成形和组织的影响.结果表明,激光焦点位置影响了接头温度场分布,随着激光焦点下移进入工件内,焊缝上部逐渐收窄变短,焊缝内气孔数量显著下降,热影响区尺寸无显著改变.此外,光束焦点位置对双相不锈钢焊缝组织具有影响.正离焦时,焊缝中部的奥氏体含量最高;当离焦量为0 mm时,焊缝金属上部、中部和下部的奥氏体分布最为均匀.     

不锈钢A-TIG焊的活性剂研制

针对304不锈钢研制了由B_2O_3,MnO,Fe_2O_3,Al_2O_3,SiO_2,TiO_2,Cr_2O_3和NaF等组成的A-TIG焊活性剂.分析了各单一活性剂对焊接熔深的影响规律,在此基础上结合304不锈钢的合金元素系统,确定了活性剂的基本组成成分.利用正交试验法对多组元配方进行了研究,得出了各组元质量分数变化对焊接熔深的影响规律,所得到的配方可使焊接熔深增加2倍多,并将8 mm厚的不锈钢钢板对接一次焊透.     

基于不锈钢阳极的TIG电弧压力特性

以不锈钢作阳极,采用静态小孔法测量TIG电弧压力.结合电弧阳极电流密度分布、伏安特性和弧长电压特性曲线分析不锈钢TIG焊的电弧压力特性.与水冷铜作阳极时的电弧压力对比,结果表明:在相同条件下不锈钢作阳极时电弧压力的分布服从高斯分布,分布半宽值较大,电弧压力峰值较低并随着电弧电流的增大、弧长的减小而增大;2种阳极条件下电弧压力峰值的差值随电流增大而增大,随弧长增大无明显变化.     

Arc characteristics of submerged arc welding with stainless steel wire

The arc characteristics of submerged arc welding (SAW) with stainless steel wire were studied by using Analysator Hannover (AH). The tests were carried out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution (PDD) curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.     

Investigation on the explosive welding mechanism of corrosion-resisting aluminum and stainless steel tubes through finite element simulation and experiments

To solve the difficulty in the explosive welding of corrosion-resistant aluminum and stainless steel tubes, three technologies were proposed after investigating the forming mechanism through experiments. Then, a 3D finite element model was established for systematic simulations in the parameter determination. The results show that the transition-layer approach, the coaxial initial assembly of tubes with the top-center-point the detonation, and the systematic study by numerical modeling are the key technologies to make the explosive welding of LF6 aluminum alloy and 1Cr18Ni9Ti stainless steel tubes feasible. Numerical simulation shows that radial contraction and slope collision through continuous local plastic deformation are necessary for the good bonding of tubes. Stand-off distances between tubes (D₁ and D₂) and explosives amount (R) have effect on the plastic deformation, moving velocity, and bonding of tubes. D₁ of 1 mm, D₂ of 2 mm, and R of 2/3 are suitable for the explosive welding of LF6-L2-1Cr18Ni9Ti three-layer tubes. The plastic strain and moving velocity of the flyer tubes increase with the increase of stand-off distance. More explosives (R>2/3) result in the asymmetrical distribution of plastic strain and non-bonding at the end of detonation on the tubes.     

不锈钢吊架主梁结构焊接应力与变形控制工艺研究

该文针对金川公司生产过程中不锈钢结构焊接存在导热率低、热膨胀系数大,焊接过程中产生焊变形和焊接应力的倾向较大现象进行分析,焊接时采取严格工艺措施,能有有效控制焊接变形,减小焊接应力的存在。     

激光-TIG复合焊接工艺参数对430不锈钢接头性能的影响

针对400系不锈钢焊接过程中焊缝附近晶粒极易长大而产生脆化,使焊接接头性能较差,很大程度上限制了其在工业领域的广泛应用,采用激光-TIG复合热源焊接冷轧430不锈钢,对焊接接头的力学性能进行了研究。结果表明,激光功率与焊接速度对焊接接头的抗拉强度和抗折能力影响最为明显,优化工艺的焊缝抗拉强度最高可达母材的89.65%、抗折强度达母材的83.53%。     

高压球形封头不锈钢堆焊问题的分析和研究

通过对尿素合成塔球形封头内表面堆焊技术进行分析,探讨了凸型封头表面堆焊方法的选择、普低钢表面不锈钢堆焊材料的确定及堆焊工艺评定、检验标准等问题。结果表明：选用正确的焊接材料和合理的堆焊工艺,在球形封头内表面堆焊不锈钢可以得到理想的抗高温、耐腐蚀效果和稳定的焊接质量。     

不锈钢A-TIG焊活性剂的焊接性研究

利用自行研制的 30 4不锈钢A TIG焊活性剂进行了焊缝外观形貌、熔深效果、接头微观组织、化学成分及接头力学性能分析的焊接工艺试验 .试验结果表明 ,使用活性剂可以使焊缝熔深比常规的TIG焊增加 1～ 2倍 ,对 8mm以下的不锈钢钢板对接无须开坡口 ,可一次焊接完成并且单面焊双面成型 ,焊缝表面成形良好 .使用活性剂后接头微观组织、焊缝的化学成分和接头力学性能均不受影响 .     

Effect of welding parameters on the heat-affected zone of AISI409 ferritic stainless steel

One of the main problems during the welding of ferritic stainless steels is severe grain growth within the heat-affected zone (HAZ). In the present study, the microstructural characteristics of tungsten inert gas (TIG) welded AISI409 ferritic stainless steel were investigated by electron backscattered diffraction (EBSD), and the effects of welding parameters on the grain size, local misorientation, and low-angle grain boundaries were studied. A 3-D finite element model (FEM) was developed to predict the effects of welding parameters on the holding time of the HAZ above the critical temperature of grain growth. It is found that the base metal is not fully recrystallized. During the welding, complete recrystallization is followed by severe grain growth. A decrease in the number of low-angle grain boundaries is observed within the HAZ. FEM results show that the final state of residual strains is caused by competition between welding plastic strains and their release by recrystallization. Still, the decisive factor for grain growth is heat input.     

410S铁素体不锈钢的静态再结晶行为

通过不同温度-时间的再结晶实验,研究热轧态铁素体不锈钢410S的再结晶行为.结果表明,对于竹节状铁素体+马氏体(质量分数约30%)的410S热轧态变形组织,为防止马氏体的再度出现以及加快再结晶过程的综合考虑,其最佳再结晶退火温度为780~800℃.在此温度下所发生的再结晶,均有一个2~5 h的孕育期,当再结晶体积分数达到50%时,结晶速度达到最大.与试样内部相比,热轧态410S板材的再结晶晶粒更易于在表面形成.经过再结晶的410S硬度从初始的86.5 HRB下降到66.5 HRB,硬度降低25%.