首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
通过亚温淬火法制备了09CuPCrNi双相钢,采用中性盐雾试验、极化曲线的测定,研究了双相化处理对耐候钢耐腐蚀性能的影响.780℃亚温淬火的09CuPCrNi双相钢在5%的NaOH、H2SO4、HCl水溶液以及3.5%的NaCl水溶液中的腐蚀行为与09CuPCrNi耐候钢相似,自腐蚀电流密度分别比09CuPCrNi耐候钢降低了17.0%、18.2%、31.2%和17.8%.在腐蚀周期分别为48 h和120 h的盐雾试验中,双相钢的腐蚀速率分别比09CuPCrNi耐候钢降低了7.9%~22.2%和2.3%~13.0%.  相似文献   

2.
09CuPCrNi耐候钢双相化的研究   总被引:1,自引:0,他引:1  
研究了09CuPCrNi耐候钢的热处理双相化工艺及双相化后的组织与性能。结果表明,09CuPCrNi耐候钢热处理双相化后,其显微组织由多边形铁素体和不规则的岛状马氏体组成,780℃淬火时的双相钢具有较高的强塑性及良好的冷加工成形性能;09CuPCrNi双相钢的耐蚀性能比热轧态稍有提高,同时具有良好的焊接性能,其热影响区抗拉强度为627MPa,相对于热轧态提高了21%。  相似文献   

3.
通过周期性浸润腐蚀试验测定了ULCB钢(%:0.05C、1.61Mn、0.51Cu、0.17Cr、0.26Ni)和耐候钢09CuPCrNi(%:0.09C、0.35Mn、0.09P、0.31Cu、0.45Cr、0.31Ni)14 mm板的耐腐蚀性能,并用偏光显微镜,X-射线衍射仪和能谱仪等研究了耐蚀机理.结果表明,ULCB钢的耐腐蚀性能优于09CuPCrNi钢;发现两种钢均存在由α-FeOOH,β-FeOOH和Fe3O4组成致密的内锈层、由α-,β-FeOOH和Fe3O4组成的疏松外锈层;Cu和Cr合金元素在锈层和锈层-钢基体界面均存在富集现象.  相似文献   

4.
直接热轧法制备Cu-P-Cr-Ni-Mo双相耐候钢   总被引:1,自引:0,他引:1  
张春玲  蔡大勇  廖波 《钢铁》2012,(7):84-88
在商用09CuPCrNi耐候钢化学成分的基础上,通过调整合金元素含量,研制出了可直接热轧双相化的Cu-P-Cr-Ni-Mo耐候钢。该钢种变形奥氏体的CCT曲线具有较宽的铁素体析出区,可作为热轧"可行的速度窗口";铁素体析出区与贝氏体转变区之间存在约80℃的奥氏体亚稳区,可作为热轧"可行的卷取范围";贝氏体转变区的右侧端部封口,可避免在卷取过程中发生贝氏体转变。根据Cu-P-Cr-Ni-Mo耐候钢的变形奥氏体的CCT曲线,制定了5种热轧双相化工艺,并采用Gleeble-3500热模拟机进行了轧制模拟,制备出了Cu-P-Cr-Ni-Mo热轧双相耐候钢。不同工艺下获得的双相耐候钢组织均为铁素体基体及其上呈岛状分布的马氏体,马氏体体积分数为17%~28%。  相似文献   

5.
利用Gleeble 3500热模拟试验机对S390转向架用耐候钢的高温塑性进行测定。通过金相显微镜、扫描电镜及能谱仪对断口组织、断口形貌和析出物进行观察和分析。利用热膨胀仪测定S390耐候钢的临界相变温度,通过Thermal-Calc软件计算微合金元素的热力学析出温度。结果表明,在1 250~650 ℃范围内,存在3个区间,第Ⅰ脆性区在1 220 ℃以上,断裂形式是由S、O等元素偏析引起的沿晶断裂;第Ⅲ脆性区为980~650 ℃,断裂形式是由析出物钉扎晶界及先共析铁素体析出引起的沿晶断裂;在1 220~980 ℃第Ⅱ脆性区内,由于动态再结晶的发生,不出现脆性区,断裂形式为穿晶塑性断裂。实际生产过程中可避开脆性区间,以减轻S390耐候钢的裂纹倾向。  相似文献   

6.
采用Gleeble 1500热模拟机研究了09MnNiDR钢的高温力学性能,得到600~1350℃范围内试样的断面收缩率、抗拉强度和应力应变曲线,并结合扫描电镜(SEM)观察断口形貌和FactSage软件进行凝固相分析。结果表明,该钢种的第Ⅰ高温脆性区为液相线温度(tL)到1350℃,高温塑性区为1350~950℃,第Ⅲ低温脆性区为950~600℃。高温塑性区为奥氏体区,具有良好塑性,但高温抗拉强度较低;第Ⅲ低温脆性区塑性降低,是由于950℃以下奥氏体向α 铁素体转变。从断口形貌观察可知,高温塑性区主要为穿晶断裂,第Ⅲ低温脆性区主要为沿晶断裂,同时在高温塑性区断口观察到液态夹杂物MnO SiO2 Al2O3,结合三元相图可知析出夹杂物熔点低于1300℃。为得到低熔点塑性好的夹杂物,应控制MnO与SiO2的比例在1~15左右,同时Al2O3的质量分数控制在10%~17%,降低连铸过程中产生内部裂纹的风险。  相似文献   

7.
某钢厂采用“KR铁水脱硫→90 t转炉→LF精炼→RH精炼→150 mm×150 mm方坯连铸”工艺流程工业化生产耐候钢09CuPCrNi(/%:0.07~0.13C,0.35~0.65Si,0.70~1.00Mn,≤0.010S,0.065~0.150P,0.10~0.30Ni,0.30~0.70Cr,0.15~0.40Cu,≤0.040Al)。通过转炉采用石灰和白云石总用量19 kg/t的少渣量、终渣二元碱度控制在2~3的低碱度造渣、吹炼氧枪枪位1.3 m左右的低枪位吹炼工艺,实现终点w[P]≥0.065%。精炼过程采用铝强脱氧及渣面复合脱氧,控制精炼炉渣碱度7~9,RH真空处理结束钙处理,连铸弱冷冷却等工艺措施,成功开发09CuPCrNi耐候钢,化学成分稳定,非金属夹杂物级别A类细≤1.0级、B类细≤1.5级、C类细0级、D类细≤1.0级、DS≤1.5级,洁净度高,轧材表面及低倍无裂纹,晶粒度6级,各项指标满足技术要求。  相似文献   

8.
研究了09CuPTiRE耐候钢的双相化热处理工艺及双相化后的组织与性能。结果表明在耐候钢09CuPTiRE(α γ)两相区(760~820℃)不同温度加热淬火获得了不同马氏体分数的双相组织;随双相化加热温度增加,双相钢马氏体含量和强度增加。  相似文献   

9.
采用金相显微镜、硬度计、万能拉伸试验机、扫描电镜等设备对含0.02%~0.11%Mo 82B钢(0.82%C,0.20%Cr)Φ12.5 mm轧材(终轧950℃,水冷至650℃,空冷)进行了显微组织和力学性能的测定,并利用JMATPRO技术对试验钢的CCT曲线模拟。结果表明:当Mo含量由0.02%提高至0.11%时,(1)82B试验钢脱碳层深度均在0.12 mm以下,HV硬度值由305小幅提高至317;(2)索氏体含量由94%降至89%,索氏体片层明显细化,屈服强度由655 MPa增至771 MPa,抗拉强度由1 054 MPa增至1 139 MPa,断面收缩率由38%增至52%,延伸率无明显变化,约为12%;(3)微量Mo的高温强化作用明显,在600℃时屈服强度由316 MPa增至369 MPa,抗拉强度由358 MPa增至399 MPa。  相似文献   

10.
《特殊钢》2020,(3)
通过GLEEBLE-3500热模拟机,研究了六种不同碳、铬和钼含量对冷镦钢(/%:0.19C,0.36C,0.19C-0.96Cr,0.39C-0.98Cr,0.19C-0.91Cr-0.21Mo和0.37C-0.98Cr-0.22Mo)在650~1 200℃温度内的高温力学性能的影响。结果表明,六种钢在650~850℃温度都存在明显的第Ⅲ脆性区。第Ⅲ脆性区的起始温度随着碳含量减少和铬含量的添加移向更高温度。铬的添加使得材料的高温塑性恶化,促进第Ⅲ脆性区扩大。而钼的添加可改善含铬冷镦钢的第Ⅲ脆性区塑性。  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。  相似文献   

12.
13.
The adolescent's breaking of the voice is the result of the substitution of the chest voice (or heavy mechanism) for the head voice (or light mechanism). In cases of late breaking, the voice is abnormally high-pitched and feeble, often with a distorted timbre, while the larynx is normal and pubescent. Such people are generally not fully aware of their voices' real nature. Therapy classically resorts to laryngeal manipulations, of which a new technique is put forward. Another therapeutic approach is based, on the one hand, on critical listening compared with a control male voice, thus enabling the subject to become aware of his own voice, and, on the other hand, on high intensity work which helps passing from head to chest voice.  相似文献   

14.
2008年中国电解金属锰发展态势浅析   总被引:1,自引:0,他引:1  
曾湘波 《中国锰业》2008,26(4):27-29
对中国电解金属锰发展的市场态势、价格行情以及原材料供应情况作了初步分析,提出我国电解金属锰行业挑战与机遇并存,只要抓住机遇、迎接挑战、夯实基础、科技创新,电解金属锰行业前景将会更加光明。  相似文献   

15.
Employed 120 male and 113 female undergraduates in a replication of H. L. Mirels's (see record 1970-10386-001) study which found 2 factors in analyzing responses to 23 items on Rotter's Internal-External Control Scale. The same polar dimensions of "luck" as the arbiter of life events as opposed to personal control were found as well as a 2nd dimension of degree of control over political and social institutions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

16.
17.
显微维氏硬度测量不确定度评定   总被引:1,自引:0,他引:1  
对显微维氏硬度测量不确定度进行评定,建立了不确定度计算的数学模型,确定了影响实验结果的各项因素,计算出了各因素的标准不确定度,得出结果的扩展不确定度,并给出最终测量结果的表达式。  相似文献   

18.
Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.  相似文献   

19.
Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

20.
The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号