60Si2Mn弹簧钢加热温度对表面脱碳的影响

表面脱碳是高速线材生产的重要问题之一.在考虑碳扩散和氧化因素后,理论计算了加热温度对60Si2Mn弹簧钢表面脱碳影响的规律,表明在900～1000℃加热温度下60Si2Mn弹簧钢脱碳层厚度存在最小值,此结果与60Si2Mn弹簧钢氧化脱碳试验结果一致.结合钢的相变进一步分析了不同加热温度下表面脱碳层形貌变化的规律,并简要介绍了脱碳控制的主要途径.     

弹簧钢盘条脱碳质量改善生产实践

脱碳是评价弹簧钢性能的重要指标之一,表面脱碳会直接影响弹簧成品的疲劳寿命.结合宝钢特钢长材有限公司线材装备特点,针对55SiCr弹簧钢的生产进行脱碳性能优化改进试验.研究表明,通过降低钢坯在炉时间、增加钢坯表面涂层,可有效避免线材表面全脱碳的产生,实现高端冷卷簧产品在宝钢特钢长材有限公司的批量稳定生产.     

φ27mm圆弹簧钢表面缺陷及脱碳浅析

本文通过对φ27mm圆弹簧钢主要质量问题及影响因素的分析，找到了成品材表面缺陷的产生原因。结合对上钢五厂、北满特钢、长特一厂三家成品材实物的金相组织、成分、碳偏的对比、提出了提高弹簧钢质量水平的技术措施和必要的、中肯的建议。     

加热期间弹簧钢55SiCr表面脱碳的影响因素研究

在实验室研究了加热温度、保温时间和加热炉内气氛对弹簧钢55S iCr表面脱碳的影响,并对脱碳反应进行了热力学分析。结果表明：在950℃-1250℃范围随温度升高,弹簧钢完全脱碳层厚度先增加后减小,1200℃时完全脱碳层厚度达到最大值,1250℃时由于氧化速度大于脱碳速度,完全脱碳层消失。弹簧钢完全脱碳层厚度分别随加热时间延长、气氛中CO2含量升高、O2含量升高和H2O（g）含量增加而明显增加。当温度为950℃、气氛中O2含量为1%、加热时间为35 min的条件下,可避免完全脱碳层的形成。     

室兰棒线材车间改善弹簧钢质量

以改善弹簧钢质量为主要目的，新日本钢公司室兰钢厂在１９９２年３月对其棒线材车间的设备进行了改造。改造的设备主要包括：加热炉、轧机、过程计算机、轧机主控制器等。     

变形条件对硅锰弹簧钢脱碳的影响

以６０Ｓｉ２Ｍｎ钢为例，研究了变形条件对硅锰钢脱碳的影响，结果表明，硅锰弹簧钢脱碳主要发生在轧前加热过程中，轧后冷却也发生脱碳。     

高速线材轧机生产螺纹钢盘卷的工艺特点

分析了高速线材轧机生产螺纹钢的工艺特点，介绍了生产螺纹钢的秒流量计算，并提出了相应的辊径计算方法。     

钒对35SiMnB弹簧钢脱碳敏感性的影响

用等温处理或等时处理测量了弹簧钢35SiMnVB和35SiMnB的脱碳层深度,结果表明：微量钒的加入可明显降低35SiMnB钢的脱碳敏感性,探讨了钒降低35SiMnB钢脱碳敏感性的原因。     

高线生产的盘卷组织异常的分析与改善

从金相角度对高线生产的几类盘卷的异常组织进行了分析,以盘条正常状态下的性能要求作为目标提出了相应的热处理组织改善的方法;根据现有设备的条件以及线卷的直径、厚度、钢种等影响因素确定了工业生产中的热处理工艺(包括热处理各阶段合适的温度、时间等).从试验的结果来看,热处理后盘卷的金相组织得到了改善,表面脱碳、力学性能等均达到了用户的要求.     

新型高强韧性弹簧钢40T 和44T 脱碳倾向的研究

新型高强韧性弹簧钢40T(%:0.41C-2. 12Si- 1.03Cr- 1.98Ni-0.31Mo-0.25V),44T(%:0.44C-2.28Si- 1.42Cr-0.25V)和弹簧钢60Si2CrVA(%:0.59C-1.65Si-1.11Cr-0.18V)的φ18 mm 和φ26 mm 试验钢材由北满特钢 20t电弧炉冶炼,经轧制、冷拔而成。各钢材经860～1000℃加热脱碳试验的结果表明,40T钢碳含量较低,并 有～2%Ni,其脱碳倾向明显低于44T钢和60Si2CrVA钢;880 ℃加热1 h时,40T钢没有脱碳,44T钢脱碳层深 0.05mm,60Si2CrVA钢脱碳层深0.15 mm;1000 ℃加热20 min,40T钢脱碳层深0.1 mm,44T 钢0.2 mm, 60Si2CrVA钢0.4 mm。40T钢脱碳倾向小,有利于提高弹簧的疲劳寿命。     

Secondary Hardening, Austenite Grain Coarsening and Surface Decarburization Phenomenon in Nb-Bearing Spring Steel

 The secondary hardening, the austenite grain coarsening and the surface decarburization phenomenon of Nb-bearing spring steel were investigated, and the effects of niobium on tempered microstructure was studied using scanning electron microscope. The results show that the micro-addition of niobium increases the tempering resistance and produces secondary hardening. The effect of niobium on the size and distribution of cementite particles is one of the primary reasons to increase the hardness after tempering. The grain-coarsening temperature of the spring steel is raised 150 ℃ due to Nb-addition. Furthermore, both the secondary hardening and the austenite grain coarsening phenomenon congruously demonstrate niobium begins observably dissolving above 1100 ℃ in the spring steel. Besides, niobium microalloying is an effective and economy means to decrease the decarburization sensitivity of the spring steels.     

不同脱氧条件下弹簧钢氧化物夹杂的性质和形貌

用光学显微镜和扫描电镜研究了工业生产条件下用不同脱氧工艺生产的60Si2MnA弹簧钢氧化物夹杂Al2O3、SiO2和铝硅酸盐的性质、形貌和控制。     

44Si2CrV 钢弹簧弹性减退机理的研究

研究了影响44Si2CrV钢弹簧在低于屈服强度的应力下长时间加载引起自由高度变化的因素。结果表明,44Si2CrV钢弹簧在900 MPa 的应力下压缩72 h,自由高度的缩短由两部分组成：表面脱碳层的塑性变形,造成对内部材料的牵制而使部分弹性变形不能恢复,由此所造成的弹簧自由高度缩短占总变形量的84%;钢的室温蠕变,占自由高度缩短的16%。     

高碳钢65Mn脱碳研究

文章对高碳钢65Mn脱碳行为进行研究讨论,从加热温度、保温时间、炉内气氛等各方面分析了高碳钢加热过程中脱碳层变化规律,为高碳钢加热制度提供理论研究依据。     

Product development of Baosteel HFW 610 Mill

Baosteel’s high-frequency electric resistance welded(HFW) 610 longitudinal seam mill(8 5/8″-24″, the yearly output 300000 t) and UOE 1422 longitudinal submerged arc welding(SAW) mill(20" -56",the yearly output 500000 t) are established in 2005 and 2008,respectively.Product specification covers whole of API 5CT standard and most of API 5L standard,terminating the history of manufacturing the medium and large size pipes at Baosteel.The yearly output increased from 1,200000 t to nearly 2000000 t.HFW 610 mill is oriented at mid size pipes,which are mainly linepipe and welded casing.The designed yearly output of HFW mill is 300000 t,including casing of 90000 t,linepipe of 180000 t,round structural pipe of 15000 t and rectangle structural pipe of 15000 t. The yearly output of oil casing line supporting the welding line is 120000 t,among which including welded casing and seamless casing of 30000 t.Baosteel’s HFW 610 longitudinal seam mill was established on October 27,2005. After the equipment trial run In October,2005 - March,2006 and equipment function examination In April,2006 - June,2006,mass production started in July 2006.And in December 2006,monthly designed capacity was achieved,reaching to 30496.644 t in welding pipe and 28 349.939 t in finished pipe.The output of 2006,2007, 2008 and 2009 was 117 067 t,223 554 t,255 791 t,and 204 424 t,with the comprehensive yield ratio 79.4%, 87.8%,90.80%and 91.92%respectively.This study introduces Baosteel HFW 610 Mill which is the world class,energy conservation and environmental protection enterprise,including product orientation,process and new product development.     

转炉生产50CrVA弹簧钢的工艺及质量控制

介绍方大特钢炼钢厂80t转炉生产50CrVA弹簧钢的工艺控制特点,通过对生产铸坯和钢材工艺质量状况进行分析,针对生产实践中的质量问题提出了改进措施。