共查询到19条相似文献,搜索用时 187 毫秒
1.
2.
通过具有不同Ti含量的三炉试验钢,研究了Ti含量对0Cr13Co9Ni5Mo 马氏体时效不锈钢的力学性能、金相组织和奥氏体含量的影响。研究结果表明:添加较多的Ti可显著降低基体组织中的有效C、N含量,大幅降低固溶、时效处理后残余/逆转变奥氏体含量,最终使冷脆转化温度显著上升,在提高强度的同时降低了钢的韧性。 相似文献
3.
4.
5.
研究了固溶温度、时效温度及时间对10Ni2Cr2MnCuMoVAl塑料模具钢热处理后的微观组织和力学性能的影响。结果表明:固溶处理后,10Ni2Cr2MnCuMoVAl钢的组织主要是板条马氏体构成,且随固溶温度的升高,马氏体板条发生明显宽化,并在890℃固溶后达到硬度最高值。时效处理后的组织由板条马氏体、粒状贝氏体和析出碳化物构成。当时效温度区间为460~520℃,随着时效温度的升高,材料的强度逐渐升高,韧性逐渐降低,并在520℃达到强度峰值;时效温度高于520℃时,随着温度升高,材料硬度降低,冲击韧性升高。分析在540℃不同时效时间处理后的性能可知,试验钢在8h达到力学性能峰值。通过比较试验钢在不同时效处理后的力学性能数据,10Ni2Cr2MnCuMoVAl钢的最佳热处理工艺为:880℃固溶处理2h+空冷,随后在520℃时效处理4h+空冷。 相似文献
6.
7.
8.
热处理对马氏体不锈钢Fv520(B)力学性能的影响 总被引:4,自引:1,他引:3
研究了热处理对马氏体沉淀硬化不锈钢Fv520(B):0.05C-14.5Cr-5.5Ni-1.8Cu-1.7Mo-0.35Nb的组织和力学性能的影响。结果得出,经1050℃固溶处理+850℃中间处理+470℃时效时Fv520(B)钢的强度达到极大值,时效温度超过520℃时,形成逆转变奥氏体,残余奥氏体量增加,620℃达到最大值。 相似文献
9.
10.
11.
研究了预处理温度对00Cr12Ni10MoTi马氏体不锈钢强度的影响。研究结果表明:在较低预处理温度下,通过非扩散α′→γ逆转变形成的奥氏体遗传了原始的锻态组织。而在950℃以上温度预处理则形成再结晶的奥氏体。由于最终750℃固溶处理遗传了预处理组织,因此预处理对钢的强度有明显的影响。材料在低于850℃预处理时最终组织中残余奥氏体量较高,不利于提高强度。850℃预处理出现峰值强度,继续提高预处理温度,强度又下降。由于950℃以上预处理形成再结晶的奥氏体,使得最终热处理后的强度稳定在较低的水平。 相似文献
12.
13.
T250马氏体时效钢晶粒尺寸对时效析出的影响 总被引:1,自引:0,他引:1
在840 ℃ 1 h固溶退火+480 ℃ 4 h时效处理条件下,不同晶粒度的T250马氏体时效钢力学性能比较试验表明,材料的性能和晶粒尺寸关系并不表现出明显的依存关系。相应的XRD和显微结构比较研究显示,马氏体时效钢的时效行为和晶粒尺寸相关。晶粒细小的马氏体钢时效时形成更多体积分数的逆转奥氏体,以膜状分布在晶界和亚晶界起到软化作用而有利于材料塑韧性的提高;同时产生更为细小弥散的沉淀相起到更为明显的强化作用。这可能是材料的力学性能和晶粒尺寸关系不明显的组织结构原因。 相似文献
14.
The mechanism of austenite reversion in 18 Ni Co-free maraging steel (250 grade) has been established by conducting extensive X-ray diffraction (XRD) and transmission electron microscopy (TEM) under differently aged conditions. It has been proposed that contrary to the precipitate dissolution mechanism suggested for the initiation of austenite reversion in 18Ni-8Co-5Mo type maraging steels, the initiation of transformation of martensite to austenite in this type of maraging steel is due to the diffusion of Ni from matrix to the dislocations and other defect structures on prolonged/high temperature ageing. This results in local enrichment of Ni which lowers both AS and MS temperatures of the region. Lowering of these transformation temperatures is responsible for the early reversion of martensite to Ni-enriched stable austenite which, on subsequent cooling to room temperature, does not transform back to martensite. 相似文献
15.
研究了马氏体时效钢00Ni14Cr3Mo3Ti(%:0.002C、14.06Ni、3.19Cr、3.06Mo、1.32Ti)750~1 050℃固溶处理的组织和力学性能。结果表明,≤900℃固溶处理,该钢奥氏体晶粒和强度无明显变化,固溶温度超过900℃时钢的奥氏体晶粒显著增大,钢的强度呈下降趋势。当固溶温度由750℃增加至900℃时,随固溶处理温度提高,钢中Fe2Mo相量降低,810℃时完全溶解,钢的冲击功由32 J提高至61 J,当固溶温度由900℃增至1 050℃,随奥氏体晶粒增大,钢的冲击功由61 J 降至26 J。 相似文献
16.
基于一种低碳硅锰系成分,结合热轧直接淬火配分工艺,开发了一种厚规格热轧直接淬火配分钢,研究了配分过程对实验钢微观组织,力学性能和冲击韧性的影响.用SEM、XRD、TEM分析观察材料的微观组织.研究结果显示,实验钢抗拉强度为1 080~1 400 MPa,屈强比为0.6~0.79,强塑积高达28 000 MPa%.等温配分钢的低温冲击韧性较动态配分钢更好,并且随着冲击温度的降低,等温配分钢冲击功比动态配分钢下降更慢.实验钢残余奥氏体含量(体积分数)为16%-28%,碳质量分数为1.05%-1.35%.同时等温配分钢较动态配分钢具有更高的残余奥氏体含量和更低的残余奥氏体碳含量. 相似文献
17.
U. K. Viswanathan R. Kishore M. K. Asundi 《Metallurgical and Materials Transactions A》1996,27(3):757-761
The effects of retained austenite produced by thermal cycling on the mechanical properties of a precipitation-hardened 350-grade
commercial maraging steel were examined. The presence of retained austenite caused decreases in the yield strength (YS) and
ultimate tensile strength (UTS) and effected a significant increase in the tensile ductility. Increased impact toughness was
also produced by this treatment. The mechanical stability of retained austenite was evaluated by tension and impact tests
at subambient temperatures. A deformation-induced transformation of the austenite was manifested as load drops on the load-elongation
plots at subzero temperatures. This transformation imparts excellent low-temperature ductility to the material. A wide range
of strength, ductility, and toughness can be obtained by subjecting the steel to thermal cycling before the precipitation-hardening
treatment. 相似文献
18.
A simple two-step thermal processing technique was devised to impart a microduplex structure in a high strength 250 grade commercial maraging steel. A martensite grain size of approximately 1 μm was obtained with interspersed islands of retained austenite whose volume fraction and mechanical stability could be controlled by varying the thermal processing conditions. The microstructure and mechanical properties of the microduplex structure were compared to those of the alloy in the maraged, martensitic condition. Due to the presence of the austenite phase, the microduplex structure showed a much smaller temperature and strain rate dependence of deformation than the martensitic structure. A remarkable increase in uniform elongation was observed below theM d temperature of retained austenite. The microduplex structure did not show any significant advantage in fracture toughness over the martensitic structure when compared at similar strength levels. By suitably adjusting austenitic stability a deformation-induced phase transformation (TRIP) of the retained austenite in the microduplex structure could be made to occur; however, the transformation did not lead to any evident increase in toughness. The micro-duplex structure exhibited a slight improvement in fracture toughness at high strain rate in contrast to the martensitic structure in which the rate effect significantly reduced the toughness. 相似文献
19.
淬火和低温处理对X30CrMoN151组织性能影响 总被引:1,自引:1,他引:0
为了探索X30 CrMoN 15 1高氮马氏体钢的最佳淬火+低温处理工艺,利用OM、XRD、SEM、EDS和EBSD等方法研究了不同淬火温度和低温处理对高氮钢显微组织和性能的影响规律。结果表明,当奥氏体化温度低于1 050 ℃,原奥氏体晶粒长大缓慢,当奥氏体化温度高于1 050 ℃后晶粒长大加剧。随着奥氏体化温度的升高,碳化物溶解加剧,油淬后的残余奥氏体呈线性升高;低温处理后残余奥氏体大幅度减少,奥氏体化温度越高冷处理后残余奥氏体下降越多。钢的硬度随淬火温度先升高后降低,在1 000 ℃硬度最高;低温处理后,硬度随淬火温度先升高后降低,在1 030 ℃硬度最高。钢的冲击韧性随淬火温度先升高后降低,在1 030 ℃时冲击韧性最佳;低温处理后,钢的冲击韧性大幅度下降。 相似文献