一种托辊的热处理工艺改进

一种托辊原调质工艺采用油冷淬火方法，检查硬度，端面和外圆硬度偏低、不均匀。通过分析研究，找出主要影响因素是冷却能力不够，现采用间歇水冷淬火方法，硬度达到技术要求，满足托辊使用条件。此次热处理工艺的改进，为今后大锻件进行调质．又开辟了一种新的方法。     

如何标注调质钢热处理后的硬度指标

1前言某些机械零件如轧钢机组用的接轴、齿轮轴等，由于服役条件不同，不仅要求有较高的强度、同时要有良好的塑性和韧性以及抗疲劳等性能，即需具备好的综合力学性能。为满足上述要求，一般选用含碳量在0．30％～0．50％的优质碳素结构钢如45钢或合金结构钢35CrMo等牌号用调质钢。钢质机械零件的调质热处理，就是钢件淬火后高温回火的复合热处理工艺。如何标注调质钢热处理后的硬度指标，目前有布氏硬度值（HBS）和洛氏硬度值（HRC）两种标注方法，究竟哪种更科学、更合理值得探讨。2各类标准中的有关技术规定2．145钢调质热处理后的有…     

热处理工艺对45钢调质性能的影响

在机械零件的加工制造过程中,调质处理是最常用也是最重要的一道工序,其目的是改善金属零部件的加工性能及提高零部件的力学性能。而调质过程中,最容易出现问题的就是硬度不符合工艺要求。通过对45钢小尺寸零件进行大量硬度试验,找出影响其硬度的主要因素,采取控制热处理生产过程中的关键生产要素后,零件达到了图纸规定的技术要求。     

核反应堆压力容器用Mn-Mo-Ni系宽厚钢板热处理工艺研究

主要介绍了舞钢核反应堆压力容器用Mn-Mo-Ni系宽厚钢板的热处理工艺研究,通过不同热处理工艺及不同淬火温度下钢的金相组织和力学性能研究,确定合理的热处理工艺。结果表明,舞钢采用合理的合金成分设计和调质工艺生产的核反应堆用16MnD5、18MnD5、20MnD5和SA533钢板强韧匹配良好,其性能完全符合规范要求。     

舞钢调质高强钢1E0682的研制与开发

结合舞钢研制专用钢种1E0682的技术要求和生产工艺特点,制定合理的调质热处理工艺,所生产1E0682调质钢钢质纯净,杂质元素含量低,化学成分均匀,综合力学性能良好。     

5%Ni钢热处理工艺研究

采用QT、QT′、QLT和QLT′四种调质工艺对5%Ni钢板进行了热处理,通过不同热处理状态下5%Ni钢板力学性能和微观组织的对比分析,确定了其合适的热处理工艺。结果表明,通常情况下,5%Ni钢板采用QT处理是合适的;而采用QT处理后的5%Ni钢板,其力学性能可以达到9%Ni钢的水平。     

5％Ni钢热处理工艺研究

采用QT、QT’、QLT和QLT’四种调质工艺对5％Ni钢板进行了热处理,通过不同热处理状态下5％Ni钢板力学性能和微观组织的对比分析,确定了其合适的热处理工艺。结果表明,通常情况下,5％Ni钢板采用QT处理是合适的;而采用QT处理后的5％Ni钢板,其力学性能可以达到9％Ni钢的水平。     

12MnNiVR钢板热处理工艺及性能研究

结合新一代石油储罐用试验钢板奥氏体组织在连续冷却条件下的相转变行为,研究分析不同淬火和回火工艺对12MnNiVR钢板组织及性能的影响规律,以确定工业生产条件下便于实施的调质热处理工艺制度,试验证明采用940℃淬火加620~660℃回火工艺方案能够获得良好的力学性能匹配。     

扇形齿轮开齿调质工艺研制

介绍了扇形齿轮经开齿后调质的一种工艺方法,调质时采取新型的防变形工装制具,减小了扇形齿轮开齿后调质的变形,保证了扇形齿轮的齿面硬度均匀,基体具有良好的综合力学性能,同时又满足了精加工的要求及精度。     

非调质预硬型塑料模具钢P20的开发

唐钢在非调质预硬型塑料模具钢P20的研发过程中,合理地控制生产工艺,实施轧后堆垛缓冷,并根据模具钢堆垛缓冷却后获得硬度设定合理的回火热处理温度,得到了理想贝氏体组织,硬度值达到HRC28~32,满足了相关技术条件的要求。     

Effect of tempering on mechanical properties of 25Co15Ni11Cr2MoE steel

The change rule of mechanical properties and impact fracture morphologies of a high Co- Ni secondary hardening ultra- high strength 25Co15Ni11Cr2MoE steel tempered at 200-750?? after quenched was studied by mechanical properties test and microstructure analysis such as optical microscope(OM) and scanning electron microscope(SEM). The results show that experimental steel after quenching and tempering has a remarkable secondary hardening effect. After tempered at 400-495??, the hardness of experimental steel can reach and beyond the quenched hardness. In this range, tensile strength, yield strength and hardness of experimental steel increase with the tempering temperature increasing, tensile strength and hardness of experimental reach maximum (57. 3HRC and 2160MPa) after tempered at 470??, meanwhile, with the tempering temperature increasing, impact toughness of experimental steel decreases during the prophase, until reaches minimum at 430??, then increases gradually, and reaches maximum after tempered at 510??. The recommended optimum heat treatment process of 25Co15Ni11Cr2MoE steel is as follow: 950???1h oil quenching??(-73??)??1h rising back to room temperature in the air ??495???5h air cooling. At this time, the experimental steel has the best strength and toughness matching.     

Tribological Performance of Austempered and Tempered Ductile Iron

Austempered ductile iron with its unique ausferritic structure is produced by an isothermal heat treatment process. Austempered ductile iron is a potential material to substitute for traditional steel castings and forgings in current industry due to its excellent mechanical properties. The tempering process is frequently used to enhance the ductility and toughness of a material and reduce residual stress. In this research, the phase transformation of austempered ductile iron was studied by applying various tempering temperatures with constant holding duration. It was found that the ausferritic structure was decomposed into dispersive cementite particles after receiving a tempering temperature of 538 °C or higher. The specific amount of retained austenite was analyzed by X-ray diffraction. The wear resistance of tempered austempered ductile iron was investigated by using a ball-on-disk sliding test configuration. The results were compared with conventional quenched and tempered ductile iron under equivalent hardness. Both austempered ductile iron and tempered austempered ductile iron samples had better wear resistance than quenched and tempered ductile iron. The results presented in this research can be utilized as a reference in the tempering treatment of austempered ductile iron material for future applications.     

热处理工艺对Cr12MoV钢组织、硬度及耐磨性的影响

本试验研究了不同淬火和回火工艺热处理对Cr12MoV钢组织、硬度和磨损性能的影响。实验结果表明:当在1050~1100℃范围内淬火、520℃回火时,得隐针马氏体+少量残余奥氏体组织,材料硬度与耐磨性均较好;当在1100℃淬火,各温度二次回火硬度均较一次回火高,当在550℃回火时,试验钢实现二次硬化,且残余奥氏体大量转变,硬度和耐磨性达最大值,材料性能最优。     

热处理对40CrMnSiB低合金超高强度钢组织和性能的影响

采用OM、SEM、JMatPro7.0分析技术,研究了热处理工艺(860～950℃淬火+200～400℃回火)对新型中碳40CrMnSiB低合金超高强度钢(0.41C,0.84Cr,0.76Mn,1.44Si,0.006B)微观组织及力学性能的影响。结果表明:920℃淬火和300℃回火钢的力学性能达到最佳强韧性匹配,即抗拉强度为1 943 MPa、屈服强度为1 931 MPa、延伸率为9%、断面收缩率为39.5%、冲击吸收功为44J、HRC硬度值为52.7。     

Microstructure and Mechanical Properties of Martensitic Stainless Steel 6Crl5MoV

 Martensitic stainless steel containing Cr of 12% to 18% (mass percent) are common utilized in quenching and tempering processes for knife and cutlery steel. The properties obtained in these materials are significantly influenced by matrix composition after heat treatment, especially as Cr and C content. Comprehensive considered the hardness and corrosion resistance, a new type martensitic stainless steel 6Cr15MoV has been developed. The effect of heat treatment processes on microstructure and mechanical properties of 6Cr15MoV martensitic stainless steel is emphatically researched. Thermo-Calc software has been carried out to thermodynamic calculation; OM, SEM and TEM have been carried out to microstructure observation; hardness and impact toughness test have been carried out to evaluate the mechanical properties. Results show that the equilibrium carbide in 6Cr15MoV steel is M23C6 carbide, and the M23C6 carbides finely distributed in annealed microstructure. 6Cr15MoV martensitic stainless steel has a wider quenching temperature range, the hardness value of steel 6Cr15MoV can reach to HRC 608 to HRC 616 when quenched at 1060 to 1100 ℃. Finely distributed carbides will exist in quenched microstructure, and effectively inhabit the growth of austenite grain. With the increasing of quenching temperature, the volume fraction of undissolved carbides will decrease. The excellent comprehensive mechanical properties can be obtained by quenched at 1060 to 1100 ℃ with tempered at 100 to 150 ℃, and it is mainly due to the high carbon martensite and fine grain size. At these temperature ranges, the hardness will retain about HRC 592 to HRC 616 and the Charpy U-notch impact toughness will retain about 173 to 20 J. A lot of M23C6 carbides precipitated from martensite matrix, at the same time along the boundaries of martensite lathes which leading to the decrease of impact toughness when tempered at 500 to 540 ℃. The M3C precipitants also existed in the martensite matrix of test steel after tempered at 500 ℃, and the mean size of M3C precipitates is bigger than that of M23C6 precipitates.     

热处理对超级13Cr不锈钢组织及拉伸性能的影响

 为了研究热处理工艺对超级13Cr不锈钢组织及拉伸性能的影响,采用了光学显微镜、X射线衍射仪、透射电子显微镜、显微硬度测试及应变速率拉伸等试验方法。结果表明,经过水淬和油淬处理的超级13Cr不锈钢组织及拉伸性能相差不大。但相比于水淬,采用油淬的试样经回火处理后塑性得到更大提升。淬火试样经回火处理后,组织变为回火索氏体。随着回火温度升高,材料的塑性先增加后减小,硬度与强度变化则相反。620 ℃回火试样含有逆变奥氏体,强度塑性组合较好。二次回火能够增加超级13Cr不锈钢中逆变奥氏体含量,但塑性变化不明显,强度下降较大。     

硼及回火温度对超高强海洋工程用钢板组织及性能的影响

为改进调质态超高强海洋工程用钢的力学性能,研究了2炉不同硼含量的钢。经控制轧制后,在实验室条件下采用不同回火温度处理以确定最佳热处理温度,并对实验钢板进行金相组织观察,利用扫描电镜和透射电镜讨论分析了硼及回火温度对组织、性能的影响。实验结果表明,硼有利于提高钢板的淬透性,含硼钢600℃回火可以满足E690的性能要求;随回火温度的提高,含硼钢和无硼钢的强度降低,伸长率升高,含硼钢的变化幅度比无硼钢大;含硼钢在630~660℃存在明显的回火脆性区,而无硼钢具有较好的回火稳定性;无硼钢在650℃回火可以满足E550的性能要求。     

热处理和形变热处理对16Mn钢板力学性能的影响

研究了回火温度对淬火和回火及形变热处理16Mn钢板各项力学性能的影响;确定了淬火和形变淬火后的适宜回火温度。     

Effect of ageing on properties of pressure vessel steels

Manganese-molybdenum-nickel steels are used in the fabrication of nuclear pressure vessels operating at temperatures up to 350°C. In this work the effects of thermal ageing in the temperature range 300–550°C for durations up to 2 × 10⁴ h have been studied in conventionally quenched and tempered, and simulated heat-affected-zone (HAZ) microstructural conditions. Quantitative fractography and Auger spectroscopy have been used to relate changes in mechanical properties with associated changes in fracture mode and grain boundary chemistry. The results show that ageing increases the ductile-brittle transition temperature by an amount dependent on material, prior heat treatment, ageing temperature and time. Embrittlement was associated with the segregation of phosphorus to grain boundaries and was successfully modelled using McLean's approach to equilibrium segregation. The embrittling potency of phosphorus was highly dependent on prior heat treatment; largest in the coarse-grained, higher hardness simulated HAZ condition, and least in the conventionally quenched and tempered conditon.     

热处理工艺对海洋工程用高强度耐低温H型钢组织及性能影响

摘要：以热轧耐低温H型钢为研究对象,采用光学显微镜、扫描电镜、透射电镜分析和力学性能测试等手段,研究了完全淬火和亚温淬火对试验钢微观组织和力学性能的演变规律。结果表明,试验型钢经780℃亚温淬火+600℃回火处理后,形成回火索氏体+铁素体的网状组织;试验型钢900℃淬火+600℃回火处理后,转变得到具有马氏体位向的回火索氏体,碳化物分布更加细小均匀,位错密度下降。2种热处理工艺制备H型钢综合力学性能优良,屈服强度均达到500MPa以上,900℃淬火+600℃回火处理后钢的屈服强度和抗拉强度更高。-40℃低温冲击韧性比热轧状态下出现大幅度提高,随着淬火温度升高冲击功更加稳定。