国内热作模具钢发展概况

本文分低合金热作模具钢、中合金热作模具钢和高合金热作模具钢叙述主要钢种、成分、热处理工艺、性能和用途，另外，介绍我国近年发展的热作模具用钢。     

热作模具钢热疲劳机理及性能改善的研究现状

热作模具钢的热疲劳性能是影响模具使用寿命的主要因素。对热作模具钢热疲劳性能的研究现状和评定方法进行了阐述,分析了组织演变、裂纹萌生和扩展对热疲劳性能的影响。同时对影响热疲劳性能的因素和改善热疲劳性能的方法进行了探讨和总结,并针对热作模具钢热疲劳研究的趋势进行了展望。     

热作模具材料研究进展

介绍了国内外热作模具钢的研究及应用情况,指出开发优质高寿命的热作模具钢有紧迫的现实意义.     

拔丝机轮毂热喷焊工艺研究

就拔丝机轮毂件的热喷焊工艺过程及相关工艺参数进行了研究,已成功应用于该轮毂件的生产中.     

H13热作模具钢的热处理工艺研究

对H13热作模具钢进行不同工艺的热处理,对其高温硬度、高温耐磨损性能、抗高温氧化性能和抗热疲劳性能进行研究。结果表明,分级退火和深冷处理有利于提高H13热作模具钢的高温硬度、高温耐磨损性能、抗高温氧化性能和抗热疲劳性能。采用分级退火并进行深冷处理可使H13热作模具钢的高温硬度增加14.2 HRC,磨损体积减少84.96%,单位面积质量增重减小74%。     

新型热作模具钢CH75的组织与性能

研究了新型热作模具钢的热处理工艺，组织与性能的关系，并与常用的热作模具钢进行比较，结果表明ＣＨ７５钢具有较３Ｃｒ２Ｗ８Ｖ和Ｈ１３钢优异的回火稳定性和高温性能，适宜做工作温度为７００℃左右的热作模具。     

1450轧机输送辊的热喷焊

热喷焊技术是制造双金属产品及修复机器零件的先进工艺技术，可节省大量贵金属材料，提高产品力学性能，降低制造成本，缩短生产周期。总结了热喷焊输送辊过程中保证喷焊质量的工艺要点，经过安装检验，生产应用，切实可行。     

V/C对铸造热作模具钢热疲劳性能的影响

采用自约束热疲劳试验方法,研究了不同V/C对铸造热作模具钢热疲劳性能的影响,并对比研究了铸造热作模具钢和H13钢的热疲劳性能。结果表明,铸造热作模具钢的热疲劳属高周热疲劳,其热疲劳性能取决于钢的热强性和热稳定性。随着V/C增加,热疲劳抗力先增后减,当V/C比为3.0时,组织中析出了细小弥散的VC,改善了钢的热强性和热稳定性,热疲劳抗力最高。铸造热作模具钢的热疲劳性能明显高于H13钢。     

新型热作模具钢的热疲劳性能

研究新型热作模具钢分别在1050、1080和1100 ℃奥氏体化后淬火,580 ℃二次回火后的热疲劳性能.结果表明:本试验条件下的新型热作模具钢在1080 ℃奥氏体化后淬火,再经过580 ℃二次回火具有较高的热疲劳性能.     

热作模具的氧乙炔焰喷焊

在5CrNiMo切边模的刃口或终锻模的型腔表面,采用氧乙炔焰喷焊粉102或粉204硬质合金粉末,制作与修复的热作模具,其喷焊层表面的硬度可达HRC58～64,延长了热作模具的使用寿命,经济效果显著。本文介绍了热作模具的喷焊工艺。     

热作模具钢的影响因素及应用

指出了热作模具钢在生产中的重要性，介绍了热作模具钢的影响因素及损坏形式．并列出了热作模具钢常用钢号、主要特性及用途。     

黑色金属模具复杂型腔超塑成型技术研究

以典型热作模具钢的复杂型腔为对象,研究了超塑制模的工模具设计及工艺,成型出连杆精锻模具型腔。系统归纳、总结了工模具钢超塑制模技术的特点并展望了未来发展趋势。     

铸造热锻模具的应用及失效分析

用新型铸造热锻模具钢和负压成型法制成半轴法兰模、护刃器模、连杆模和五速齿轮模,并进行了现场应用,铸造热锻模具断裂失效分析,测试了各模具的HRC、αK、K1C,探讨了影响铸造热锻模具早期断裂失效的关键性能指标。     

铜元素在钢表面氧化过程中富集规律的研究

对不同铜含量的钢在表面氧化过程中铜的富集规律进行了研究。研究结果表明:钢的热加工性能与钢中铜含量有着密切联系。残余铜含量越高,晶界与基体界面氧化腐蚀越严重,热脆性倾向越大;热加工时间越长,液态富铜相渗透晶界越深,分布面越宽,晶界富集量越多;热加工温度越高,晶内、晶界氧化越剧烈。合理地改善热加工时间和温度,可以减轻钢中残余铜元素所导致的热脆性。     

等温球化退火对H13钢组织和性能的影响

对H13热作模具钢的等温球化退火工艺进行了试验研究。结果表明，与常规退火工艺相比，在相同的淬火、回火工艺条件下，经等温球化退火，可获得更为细化的组织，模具的综合性能有较大的改善，使用寿命提高了50％。     

Optimization of process parameters for the manufacturing of rocket casings: A study using processing maps

Maraging steels possess ultrahigh strength combined with ductility and toughness and could be easily fabricated and heat-treated. Bulk metalworking of maraging steels is an important step in the component manufacture. To optimize the hot-working parameters (temperature and strain rate) for the ring rolling process of maraging steel used for the manufacture of rocket casings, a systematic study was conducted to characterize the hot working behavior by developing processing maps for γ-iron and an indigenous 250 grade maraging steel. The hot deformation behavior of binary alloys of iron with Ni, Co, and Mo, which are major constituents of maraging steel, is also studied. Results from the investigation suggest that all the materials tested exhibit a domain of dynamic recrystallization (DRX). From the instability maps, it was revealed that strain rates above 10 s⁻¹ are not suitable for hot working of these materials. An important result from the stress-strain behavior is that while Co strengthens γ-iron, Ni and Mo cause flow softening. Temperatures around 1125 °C and strain rate range between 0.001 and 0.1 s⁻¹ are suitable for the hot working of maraging steel in the DRX domain. Also, higher strain rates may be used in the meta-dynamic recrystallization domain above 1075 °C for high strain rate applications such as ring rolling. The microstructural mechanisms identified from the processing maps along with grain size analyses and hot ductility measurements could be used to design hot-working schedules for maraging steel.     

淬火温度对 Si及K/Na、Mo复合变质H13钢性能的影响

研究了淬火温度对Si及K/Na、Mo复合变质H13钢性能的影响,试验结果表明,淬火温度提高可使Si及K/Na、Mo复合变质H13钢的抗热疲劳性能增强,有利于延长H13钢热作模具的使用寿命.     

镍基涂层/碳基薄膜复合体系磨蚀行为

利用非平衡磁控溅射技术在316L不锈钢基底和316L不锈钢基底喷焊Ni60C涂层表面分别制备a-C、a-C:H、a-C:Cr3种类金刚石碳基(DLC)薄膜,对比分析了不同防护体系在5%H_2SO_4(质量分数)溶液中的耐磨蚀性能。结果表明:较单层DLC薄膜,Ni60C/DLC复合体系膜-基结合强度大幅提高,腐蚀磨损性能显著改善,其摩擦系数在0.05～0.14之间,腐蚀磨损率在0.66×10~(-8)～5.7×10~(-8) mm~3/N·m之间。Ni60C涂层作为硬质支撑层提高了薄膜的承载能力,且有效抑制了腐蚀摩擦过程中碳基(DLC)薄膜的石墨化进程,提高了Ni60C/DLC复合体系耐磨蚀性能。     

Feasibility of electro-slag cast steel for hot-working tools

A study on electro-slag cast steel has been performed to assess the feasibility of its use in hot-working tools in place of traditional forged steels. In this study, some important material properties that are essential for the proper performance of hot-working tool steels have been measured. The properties of the electro-slag cast steel are compared with those of hot-working tool steels currently used in industrial practices. The use of electro-slag cast steel in specific applications has been evaluated and compared with the operational performance of currently used steels in industrial environments. The wear resistance, impact toughness, thermal fatigue resistance, and repair weldability of electro-slag cast steel have been determined. The material properties were found to be comparable to existing hot-working tool steels. The number of effective blows obtained from an industrial application test also confirms that electro-slag cast steel is a feasible material for hot-working tools.     

H13钢的热处理工艺研究

H13钢(4Cr5MoVlSi)是新型的热作模具钢,可以广泛用于要求高韧性和冷热疲劳抗力,工作温度≤700℃的热作模具或轴类件。本文论述了不同锻后退火工艺、淬火工艺、回火工艺对该钢组织和性能的影响,提出了最佳热处理工艺参数。实践证明,能提高H13钢的使用寿命和性能,具有明显的经济效益。