共查询到19条相似文献,搜索用时 78 毫秒
1.
分析了济钢ASP产线X70管线钢的生产工艺及性能。研究表明,将管线钢的C控制在0.07%以内,并适当添加Nb、Ti等微合金元素,P、S控制在0.010%和0.005%以下,在济钢采用TMCP工艺,可以获得高强韧的针状铁素体管线钢卷,各项力学性能指标均达到标准要求。整卷性能稳定,同卷强度差<20MPa。 相似文献
2.
3.
4.
简要介绍了高强级别管线钢的性能要求及国内外生产现状.就碳的微合金化特点、碳含量对焊接性能的影响和超低碳贝氏体微合金化管线钢(ULCB)等方面,讨论分析了碳含量对管线钢性能的影响特点,并指出了管线钢碳含量现状及控制工艺特点.分析认为,碳氮的间隙固溶强化不是主要的强化方式,微合金管线钢碳含量的控制趋势是逐步降低,管线钢理想的碳含量范围应为0.01%~0.05%. 相似文献
5.
6.
7.
介绍了管线钢中氮的危害,结合管线钢化学成分和生产工艺,分析氮的来源、溶解和扩散机理,基于转炉冶炼、LF炉精炼、RH炉精炼、连铸等生产工艺特性,对不同工序钢水中氮的数据进行采集和分析,系统研究提高转炉吹炼命中率、改善造渣制度、强化出钢管理、全程底吹Ar控制,LF微正压操作,RH真空处理,连铸保护浇注等措施对降氮和控氮的影响,指出连铸坯氮含量偏高的主要原因。为管线钢冶炼的降氮和控氮,强化重点工艺环节的控制,优化改进控制工艺,提供了科学依据,形成了一套全工序控制钢水氮的措施,确保高级管线钢中氮质量分数控制在0.0045%以下。 相似文献
8.
文章介绍了八钢公司采用铁水脱硫预处理、复吹转炉、LF精炼、板坯连铸工艺开发X60管线钢的过程。在成分设计上应用了Nb、V、Ti微合金化,采用低碳含量,提高产品的韧性和延性,同时具有良好的焊接性能。将Nb、V、Ti微合金化与热机械轧制工艺(TMCP)相结合,充分应用管线钢的晶粒细化、固溶强化、析出强化和相变强化等机制,提高管线钢的强度和韧性。采用微钛处理技术,改善管线钢焊接热影响区的韧性。生产控制上采用纯净钢冶炼工艺和连铸的保护浇铸工艺,降低钢中的氮含量、非金属夹杂和硫含量,并对钢水中的Al2O3夹杂进行钙处理,提高管线钢热轧卷板的断裂韧性。采用该工艺生产的X60管线钢成品[S]≤0.0050%,[N]≤0.0055%,钢中的A、B、C、D各类夹杂物能控制到1.5级以下。钢材的抗拉强度控制在550~670 MPa,屈服强度控制在475~545 MPa,屈强比控制在0.82~0.90,断后伸长率控制在35%~43.5%,-20℃夏比V型横向冲击功AkV88~112 J,各项力学性能完全满足国内外标准和用户技术条件要求,已形成批量供货能力。 相似文献
9.
为了提高X65M管线钢生产质量控制水平,莱钢炼钢厂采取了成分优化设计,转炉和精炼工序低磷、低硫工艺控制,连铸机全保护浇铸工艺等措施。实践结果表明:X65M管线钢成分合格率达到99.9%,夹杂物控制合格率达到100%,且铸坯组织均匀,钢中N、O的质量分数平均值控制在30×10-6以内。 相似文献
10.
11.
12.
The low-carbon magnesia-carbon(MgO-C)composites containing 3%(mass fraction,the same below)carbon were prepared by adding various types of carbon black(CB).The mechanical properties,oxidation resistance at 1100 ℃ in oxidizing atmosphere,and thermal shock resistance after 5 times dipping in 1600 ℃ molten steel of the low-carbon composite samples were investigated,compared with a commercial high-carbon MgO-C composite containing carbon of 16%.The results show that the mechanical properties,oxidation resistance and thermal shock resistance of the low-carbon samples are improved with the decrease of CB particle size.Thermal shock resistance of the low-carbon sample containing nanometer CB N220 is obviously better than that of other low-carbon samples,and reaches the level of the high-carbon samples. 相似文献
13.
14.
15.
异型坯表面纵向微细裂纹研究 总被引:1,自引:0,他引:1
通过对异型坯腹板表面纵向微细裂纹宏观和显微特征的研究、保护渣性能检验、连铸二冷段铸坯表面温度测定和连铸设备的检查等,确定了异型坯腹板表面纵向微细裂纹的产生原因主要有结晶器保护渣性能波动大、连铸冷却工艺不合理、设备状况差及连铸操作不规范等.根据分析结果,同时结合异型坯连铸温度场、应力场数值模拟结果,提出了改进措施,使异型坯表面纵向裂纹发生率由10%下降到1.5%以下. 相似文献
16.
Ulrich Brill 《国际钢铁研究》2005,76(8):603-606
The nitrogen content of Ni‐base superalloys for high temperature service is generally kept below about 0.05 wt.‐% to avoid detrimental precipitation of nitrides. These nitrides are said to have a harmful influence on mechanical properties and workability of these alloys. However, some recent studies and research conducted with nitrogen strengthening of Ni‐Cr‐alloys have resulted in an alloy with excellent physical and mechanical properties. The applied PESR (Pressurized Electro‐Slag Remelting)‐Technology provided up to 1.0 wt‐% nitrogen in a NiCr7030‐alloy.The homogeneously distributed nitrides prevent the alloy from excessive grain growth thus providing stable mechanical properties, i.e. impact toughness even after long term exposure. The new alloy easily exceeds Rm= 850 MPa at room temperature and 600 MPa at 600 °C as relevant design values. This paper introduces this new alloy with its very special metallurgy, microstructure, and its physical and mechanical properties. 相似文献
17.
采用50%返回料+50%新料的新工艺熔炼镍基K4169合金,进行了4次返回料的熔炼试验。采用金相显微镜及扫描电镜对新料合金及返回料合金的微观形貌进行了观察,用直读光谱仪对不同返回次数的合金进行了化学成分分析、对其力学和持久性能进行测试,研究了返回料熔炼对合金化学成分、微观组织及力学性能的影响。结果表明:随返回次数增加,化学成分无明显变化,合金的气体含量略呈下降趋势且总含量低于40×10-6,返回料冶炼过程中可不添加B和Zr。K4169合金凝固组织为典型枝晶结构,返回料对K4169合金的铸态枝晶组织没有明显影响。MC型碳化物及Laves相在热处理过程中部分分解,析出针片状δ相,在所有元素中,Nb的偏析最为严重,通过适当延长固溶处理时间可提高元素Nb的分布均匀性和抑制δ相的生成。返回料合金的室温拉伸强度及屈服强度随返回次数增加略有增加,合金的持久寿命较新料合金略有降低,但均明显超过现有技术标准规定的要求。熔炼的返回料合金具有良好的中温塑性,总体上与新料的质量水平相当。返回料合金的铸造性能与新料相当,可以代替新料用于铸件生产。 相似文献
18.
Dual phase steels are characterized by a microstructure consisting of ferrite, martensite, retained austenite, and/or lower
bainite. This microstructure can be altered by tempering with accompanying changes in mechanical properties. This paper examines
such changes produced in a vanadium bearing dual phase steel upon tempering below 500 °C. The steel mechanical properties
were minimally affected on tempering below 200 °C; however, a simultaneous reduction in uniform elongation and tensile strength
occurred upon tempering above 400 °C. The large amount of retained austenite (≅10 vol pct) observed in the as-received steel
was found to be essentially stable to tempering below 300 °C. On tempering above 400 °C, most of the retained austenite decomposed
to either upper bainite (at 400 °C) or a mixture of upper bainite and ferrite-carbide aggregate formed by an interphase precipitation
mechanism (at 500 °C). In addition, tempering at 400 °C led to fine precipitation in the retained ferrite. The observed mechanical
properties were correlated with these microstructural changes. It was concluded that the observed decrease in uniform elongation
upon tempering above 400 °C is primarily the consequence of the decomposition of retained austenite and the resulting loss
of transformation induced plasticity (TRIP) as a contributing mechanism to the strain hardening of the steel.
B. V. N. RAO, formerly Senior Research Engineer, Analytical Chemistry Department, General Motors Research Laboratories 相似文献
19.
为了系统研究临界区退火和全奥氏体区退火对中锰钢性能的影响,为中锰钢的实际应用提供理论基础,在650~900 ℃范围内系统研究了冷轧中锰钢的显微组织和力学性能,并通过断口形貌观察分析了试验钢的断裂特性。结果表明,试验钢在临界区退火的综合力学性能明显优于全奥氏体区退火。650~750 ℃退火时,抗拉强度在1 000 MPa左右,强塑积超过30 GPa·%,发生韧性断裂,宏观上可以观察到明显的层状裂纹,微观下为大量韧窝;在800~900 ℃退火时,抗拉强度在743~1 154 MPa范围内波动较大,强塑积不足10 GPa·%,断口平整,发生脆性沿晶断裂;退火温度为650 ℃时,组织为片层状和等轴状的奥氏体、铁素体双相及大量渗碳体;随着退火温度的升高,渗碳体逐渐溶解消失,等轴状组织所占体积分数明显增加,奥氏体体积分数也不断增加,在750 ℃时达到52.2%;退火温度为800 ℃时,有马氏体产生,奥氏体体积分数下降;退火温度为900 ℃时,组织基本为马氏体,残留奥氏体体积分数仅为14.6%。 相似文献