【作者】 李子章；

【导师】 黄润秋；

【作者基本信息】 成都理工大学 ， 地质工程， 2011， 博士

【摘要】 我国热压孕镶金刚石的研制始于六十年代后期,已经有四十余年的历史。由于热压孕镶金刚石钻头的性能可调范围广,对岩石的适应能力强,钻进效率高,使用寿命较长等特点,被广泛应用于地质钻探、工程地质勘查、岩土钻掘施工等领域。但是,由于钻头制造工艺的原因,金刚石在钻头胎体中的分布是不均匀的,从而极大地影响了钻头的使用效果。近年来,在金刚石锯切工具行业,使金刚石在胎体中能够均匀分布的技术(简称金刚石均布技术)得到快速发展,采用该技术制造的金刚石锯切工具,性能得到显著改善,从而使金刚石均布技术成为金刚石工具行业的研究热点。本论文提出的金刚石定位排布的热压孕镶金刚石钻头研究,是在金刚石工具行业先进的均布技术基础上,结合热压孕镶金刚石钻头的特点,通过胎体配方、钻头结构、制造工艺等关键技术研究,在热压孕镶钻头胎体中实现金刚石按设计的位置进行准确定位排布,从而达到改善钻头工作性能的目的。定位排布技术是改善金刚石钻头性能的全新的技术手段,开展这方面的研究工作,对于提高金刚石钻头品质,促进相关行业技术进步有十分重要的意义。论文从胎体配方、金刚石参数和钻头结构等方面详细介绍了国内外孕镶金刚石钻头的研究进展;对金刚石均布排布技术在国内外金刚石工具行业的应用情况及工艺现状进行了全面分析;论述了进行金刚石定位排布技术研究的重要性,明确了主要的研究内容,确定了论文的研究思路和采用的技术路线。论文从孕镶钻头的结构入手,分析了孕镶金刚石钻头胎体的作用,详细介绍了胎体的主要成份构成、各组份的作用以及衡量胎体性能的主要技术指标,指出了定位排布钻头对胎体粉料的特殊要求;对胎体块的烧结工艺进行了深入分析,采用中频炉烧结法,烧结温度为1000℃、升温速度为100-120℃/min、保温时间为5min的烧结工艺参数;分别对采用铜基单体粉配方、铜镍锰预合金配方和铁基预合金配方进行了胎体硬度和耐磨性的测试,对三种胎体配方的性能进行了分析,总结出了不同配方对胎体性能的影响规律。论文对孕镶金刚石钻头的钻进机理和金刚石的破碎形式进行了探讨,对钻头的磨损情况以及金刚石在底唇面的分布对钻进的影响进行了深入分析,明确了金刚石定位排布的优越性,为定位排布钻头设计提供了理论基础。论文首次采用轴向间距、周向间距和径向间距三个参数来衡量金刚石在胎体中的位置,分析了不同参数对钻头性能的影响。论文对金刚石在钻头底唇面上的定位排布方式进行了系统研究,并根据钻头底唇面内外径磨损快、中间部位磨损慢的特点,采用了把钻头分为内、中、外三个不同的环型区带,并分别在这三个环形区带内采用不同的金刚石定位参数进行钻头设计,从而达到使钻头均衡磨损的技术方法。确定了地质钻探常用粒度的金刚石定位参数:采用粒度为40/45目的钻头,金刚石的轴向间距设计为0.4mm,在内、外环带,周向间距和径向间距均为1.0mm,在中间环带,周向间距为1.2mm,径向间距为1.0mm;采用粒度50/60目金刚石的钻头,金刚石轴向间距为0.3mm,在内、外环带,径向和周向间距为0.7mm,在中间环带,周向间距为1.0mm,径向间距为0.7mm。新的钻头设计方法,使孕镶钻头设计更加精确,提高了钻头的设计水平。论文结合定位排布金刚石钻头的特点,在传统热压金刚石钻头制造工艺的基础上,通过增加金刚石定位排布孕镶胎体块制造工序,制定了金刚石定位排布钻头制造的工艺流程。在定位排布钻头制造中,关键的金刚石定位排布孕镶胎体块制造环节主要采用薄片压制设备、真空模板排布金刚石设备和冷压成型及自动脱模设备,分为胎体薄片的压制、金刚石定位排布和冷压成型三个工艺步骤。论文对压片模具、冷压组合钢模、烧结石墨模具等对钻头制造影响较大的模具设计和加工进行了深入的研究。确定了钻头的热压烧结工艺参数为:单体粉末配方的烧结温度为1000℃、预合金配方为930℃、压力均为150kgf/cm2、保温时间均为6分钟。论文采用的钻头制造工艺流程和设备是根据定位排布钻头的特点,通过优化设计、功能改进、系统集合而成,在国内地质钻探行业首次采用,具有金刚石定位准确、机械化程度高、批量生产能力强的特点。试制了8只钻头在四川邻水孔家山井田煤矿和广西横县孟村铅锌矿等2个矿区3类地层进行了野外钻进试验,并对试验结果进行了全面分析。新型的钻头在燧石含量极高的灰岩中钻进,寿命和钻进时效较普通钻头分别提高34.38%和16.7%;在砂泥岩中的钻进时,在胎体磨损高度仅为0.5mm的情况下,进尺33.06米,平均钻速3.59米/小时;在花岗岩中钻进,较普通钻头的时效提高50%,寿命提高100%以上。试验结果表明,金刚石定位排布的热压孕镶钻头性能大幅改善,钻进效率和使用寿命大幅提高,其技术成果具较高的实用价值。更多还原

【Abstract】 It has been 40 years since the study on hot-pressed diamond bits had begun in the late 1960s in China. Widely employed in the fields of geological drilling, geological exploring, geotechnical drilling and construction,the hot pressing technology has long been the major methodology for the manufacturing of diamond bits which enjoy more flexibility in the adjustment of bit properties, stronger adaptability to different rocks, longer lifetime and higher working efficiency. However, with the traditional manufacturing technology, the distribution of diamonds in bit matrix is still uneven, which has greatly affected the bit’s working efficiency. In recent years, the uniform distribution technology for diamond drilling bit, which has greatly improved the bit efficiency, has developed rapidly and come into the core of the study in this area.On the basis of the uniform distribution technology, this paper has conducted the research into the diamond positioning distribution technology in hot-pressed impregnated diamond drilling bit, by exploring the properties of hot-pressed impregnated diamond bit and studying the matrix formula, positioning arrangement of the bit, and the bit manufacturing process involved, so as to largely promote the quality of diamond bit. Since the diamond positioning distribution technology is a brand-new technique in promoting the quality of diamond, doing research in this field is of great significance in promoting the quality of diamond and the technological advancement in the related industries.This paper starts from the introduction of the domestic and foreign researches on the matrix formula, the positional parameters of diamond, and the structure of the hot-pressed impregnated diamond bit; it, then, proceeds to demonstrate the status quo of the uniform distribution technology and its application in manufacturing diamond tools at home and abroad; elaborating on the significance of studying the diamond positioning distribution technology, this paper adopts the following methodology in the present research.Firstly, the structure of hot-pressed impregnated diamond bit has been studied, with an analysis of its matrix in terms of primary matrix components and each of their effects, required matrix performance, and the major technical indicators in measuring its performance; with the further study of bit sintering process, the research has experimented on the IF furnace sintering in producing bit matrix, with a sintering temperature at 1000℃, the heating rate at 100-120℃/min, and the holding time of 5min; therefore, matrix hardness and wear resistance have been tested with the three matrix formulae, i.e. the Cu elemental powder formula, the pre-alloyed copper-nickel-manganese formula, and the pre-alloyed basis iron formula. Based on the above experiments, it has been justified that the change in matrix components leads to varied matrix performances.Next, the drilling mechanism and the matrix fragmentation have been elaborated. Therefore, the in-depth analysis of stress and abrasion of bit end, as well as the drilling effect of diamond distribution on bit bottom lip, has well justified the superiority in diamond positioning distribution, thus providing the theoretical support for the design of positioning distribution. To locate the diamond in the matrix, the study has initiated the use of three parameters, i.e. axial spacing, circumferential spacing and radial spacing, to analysis different effects on drilling bit performance caused by different parameters. After a systematic study on the diamond distribution on the bit bottom lip, in accordance with greater wear effects in inner-most and outer-most surfaces and the least wear effects in the middle part, this study has proposed the three-layered circular distribution of diamond grain,and different diamond parameters were used in inner, middle and outer ring of three different zones for the design of bits, so as to avoid unbalanced wear of bits. Positioning parameters for bit diamonds generally used in geological drilling have been designed, for diamond in particle size of 40/45 mesh, and for the diamond in particle size of 50/60 mesh, respectively. As to the positioning of the diamond in particle size of 40/45 mesh, the axial spacing is set as 0.4mm, radial spacing 1.0mm, with circumferential spacing of 1.2mm and radial spacing of 1.0mm in the middle layer; meanwhile, as to the distribution of the diamond in particle size of 50/60 mesh, the axial spacing is set as 0.3mm, radial spacing 0.7mm, with circumferential spacing of 1.0mm and radial spacing of 0.7mm in the middle layer. With the above new positioning of bit diamonds, the design of diamond bit is brought under control, more accurate and effective. Employing the diamond positioning distribution, the study has redesigned the manufacturing process of hot-pressed diamond bit, by adding to the manufacturing process of impregnated bit matrix a new procedure of diamond positioning distribution. The equipment involved in the new procedure of diamond positioning distribution include the equipment for pressing tablet mold, for the vacuum modeling of diamond distribution, for the cold composition and automatic ejection, which are used in respective procedure thus concerned. Based on a further study of the most widely used mold in bit manufacture, such as the tablet mold, the cold steel composition, and the sintering graphite mold, the sintering technology has been proposed with the sintering temperature of 1000℃for elemental powder formula and of 930℃for pre-alloy formula, and with an average stress at 150kgf/cm2 and the average holding time of 6min. In this study, the bit manufacturing process together with the equipment for diamond positioning distribution becomes an integrated system for optimal design and efficiency enhancement, which has been first utilized in geological drilling, featuring accurate positioning, high degree of mechanization and great productivity.Finally, 8 diamond bits, thus produced with positioning distribution technology, have been experimented in the field drilling tests at the coal-mining site in the Kongjia Hill of Linshui County in Sichuan Province, and that in Meng Village of Heng County in Guangxi Province. It has been found that the diamond bit, gains a longer lifetime by 34.38% and a higher drilling rate by 16.7% than conventional bit, when drilling the limestone layer with high content of flint; while drilling in shale layer, it reaches 33.06m in lifetime and 3.59m/h in drilling rate with an abrasion extent of 0.5mm; when drilling in granite layer, bit lifetime has increased by 100%, and the drilling rate increased by 50%. In this way, the bit performance has been greatly promoted by the application of bit positioning distribution technology. The experiments have shown that the performance and quality of hot-pressed impregnated diamond drilling bit have been improved significantly, and the diamond positioning distribute technology is of high practical value and wide prospect.更多还原