井下工具螺纹粘扣原因分析

针对井下工具螺纹3-1/2″EU的粘扣现象,对螺纹材质化学成分、金相组织、力学性能、螺纹参数进行检测和分析,并通过螺纹上卸扣试验和静水压力试验分析磷化对螺纹粘扣影响程度。结果表明,螺纹表面未经磷化处理,导致螺纹润滑性下降,摩擦力增加,造成螺纹粘扣;而磷化螺纹可明显提高螺纹抗粘扣能力,能够提高螺纹密封性能。     

油套管螺纹连接抗粘扣技术的研究现状及展望

螺纹粘扣作为油套管中最常见的失效形式，一直是国内外冶金和石油系统的研究重点。对油套管粘扣现象作了简单的解释，通过对国际上近20年来油套管螺纹连接抗粘扣技术研究情况的分析总结，归纳了各种关于管螺纹粘扣失效的机理研究、管螺纹参数优化及其检测研究、螺纹脂和螺纹镀层的研究、油套管特殊螺纹连接的研究、油套管上卸扣的操作规范的研究，介绍了其主要研究成果，指出存在的问题，并探讨了进一步开展研究的方向。     

螺纹脂对抗粘扣性能的影响研究

为研究螺纹脂类型对抗粘扣性能的影响,分别选取了API标准样管、API标准扣型、API标准处理方式、API标准上扣参数、高精度的试验设备等,使用相同的扭矩和螺纹脂涂抹方式,用4种螺纹脂在4支标准样管上进行上卸扣试验。试验结果表明,螺纹脂对抗粘扣性能有重要影响,选取的4种类型螺纹脂中只有BESTOLIFE 2000螺纹脂可以满足API标准9次上卸扣螺纹无严重损伤要求,B96101只能承受6次上卸扣螺纹无损伤,8401和DH-2螺纹脂3次上卸扣后螺纹就会发生严重损伤。     

API圆螺纹油管接头连接性能的非线性有限元分析

ＡＰＩ圆螺纹油管在油田有着广泛的应用，在使用过程中，发现油管接头有粘扣甚至滑脱现象。为了探讨ＡＰＩ圆螺纹接头粘扣和滑脱的机理，改善螺纹接头的连接性能，对螺纹接头在机紧过盈，轴向拉伸载荷作用下进行计算机仿真的非线性有限元分析。分析结果表明，啮合螺纹接触应力过高造成螺纹粘扣；管体螺纹接头部分强度刚度较低限制了螺纹接头的连接强度。     

API套管圆螺纹接头粘扣失效分析

粘扣是套管接头的失效形式之一，它发生在套管上扣操作过程中的螺纹处。套管一旦发生粘扣，直接影响到套管柱的密封性能和连接强度。通过对套管接头的上卸扣实验和接头螺 凶数值计算，对套管产生粘扣的原因进行了研究，并利用摩擦磨损机理，描述了粘扣的产生过程。     

圆螺纹油管接头齿而接触应力与粘扣分析

分析了ＡＰＩ圆螺纹油套管发生粘扣和基本过程及机理。利用Ｉ－ＤＥＡＳ和ＭＡＲＣ软件计算了拧接过程螺纹齿面的接触应力，定量分析了管体（公螺纹）和管接箍（母螺纹）的锥度变化对齿面接触应力的影响。认为产生粘扣的主要原因是螺纹齿面局部过量的塑性变形，通过变锥度的方式能使接触应力分布规律得到改善，并在现场生产中得到验证。     

圆螺纹油管接头齿面接触应力与粘扣分析

分析了ＡＰＩ圆螺纹油套管发生粘扣的基本过程及机理。利用Ｉ－ＤＥＡＳ和ＭＡＲＣ软件计算了拧接过程螺纹齿面的接触应力，定量分析了管体（公螺纹）和管接箍（母螺纹）的锥度变化对齿面接触应力的影响。认为产生粘扣的主要原因是螺纹齿面局部过量的塑性变形，通过变锥度的方式能使接触应力分布规律得到改善，并在现场生产中得到验证。     

API圆螺纹套管接头上卸扣力学性能实验研究

为了深入了解上卸扣工况对套管接头力学性能的影响,给研究套管接头产生粘扣的力学因素提供实验依据,采用在套管接 头内外表面巾应变片的方法,利用全尺寸上卸扣试验机,对套管接头进行了重复上卸扣实验,测量了接头内外表面应变和上卸扣扭矩。通过实验结果分析,确定了影响接头粘扣的主要力学条件和部件,所确定部件与实际操作过程发生粘扣部件相吻合,采用增大接箍螺纹端部锥度,降低端部接触压力的方法,提高了套管的抗粘扣性能     

油套管圆螺纹连结粘扣原因及其防止方法

介绍了油套管圆螺纹加工方法，以及加工中产生尺寸误差以及应力不均匀分布原因，圆螺纹连接有时出现粘扣的原因、形成机理及其防止方法。     

快速上扣螺纹接头的有限元分析及优化设计

快速上扣螺纹接头是一种适用于大口径套管的接箍螺纹连接方式,具有对扣容易、上扣效率高、不错扣的特点,特别适合于海上等恶劣环境作业.根据市场需求,宝钢开发出了自主知识产权的快速上扣螺纹接头.介绍了宝钢快速上扣螺纹接头的优化设计过程,利用有限元方法对齿形角、螺纹中径、锥度、连接强度等进行分析,确定了接头的优化结构.开发的快速上扣螺纹接头产品分别在宝钢实验室和西安管研院完成并通过了全尺寸实物性能试验,13.375 in规格已在油田完成下井试验,证明产品的上扣完整性、密封完整性、结构完整性满足油田使用要求.     

The chemistry and structure of wear-resistant,iron-base hardfacing alloys

The chemistry and microstructure of iron-base alloys resistant to galling wear were determined by using optical microscopy and scanning electron microscopy (SEM). Castings and weld overlays, deposited by the gas tungsten arc and plasma arc welding (GTAW and PAW, respectively) processes, were evaluated. The microstructure typically consisted of a primary austenitic matrix, eutectic carbides (M₇C₃ type), and noneutectic carbides. Processing techniques that resulted in high cooling rates yielded microstructures with finer features, less complete partitioning of alloying elements to the carbides, and improved resistance to galling wear. Carbon and manganese appeared to improve resistance to galling wear. Nickel was detrimental to galling wear resistance. Formerly with AMAX Materials Research Center Formerly with AMAX Materials Research Center Formerly with AMAX Materials Research Center     

Coating of a steel wire with copper

The process of coating of a steel wire with liquid copper at a high speed (>1 m/s) is considered. The results of long-term studies of copperizing under laboratory conditions and electron-microscopic investigation of the copper–steel adhesion are used to develop a mathematical model for coating of a steel wire with copper and to create a commercial setup to implement this process.     

挤压铝型材表面拉毛形成原因分析

采用直读光谱仪、扫描电镜等设备,通过分析合金成分、挤压工艺、铸棒表面质量对型材拉毛缺陷的影响,研究拉毛形成的原因.结果表明,拉毛缺陷前端有明显沿挤压方向台阶状划伤痕迹,收尾瘤状颗粒形状不规则;成分与基体接近,其周围分布Fe、Si、C、O含量高的异质颗粒;挤压速度过快,挤压出口温度过高,铸棒表面粗糙都会加剧表面拉毛的产生...     

宝钢钻井用套管实物性能试验研究

针对套管在钻井过程中受到不同程度磨损的情况,模拟套管均匀磨损和偏磨工况,采用全尺寸实物试验方法,对宝钢Φ139.7×9.17 mm P110钻井用套管进行了拉伸失效和静水压试验研究。研究结果表明:宝钢钻井用套管,在上、卸扣试验中螺纹和密封面未发生黏着磨损,拉伸失效载荷大于API BUL 5C2规定接头连接强度最小值17.7%,失效内压值大于API BUL 5C2规定最小内屈服强度46.7%。对该产品进行了钻井试验,完成油层套管钻井井深1 160 m,满足了油田使用要求。     

Some observations of the influence of δ-ferrite content on the hardness,galling resistance,and fracture toughness of selected commercially available iron-based hardfacing alloys

Iron-based weld hardfacing deposits are used to provide a wear-resistant surface for a structural base material. Iron-based hardfacing alloys that are resistant to corrosion in oxygenated aqueous environments contain high levels of chromium and carbon, which results in a dendritic microstructure with a high volume fraction of interdendrite carbides which provide the needed wear resistance. The ferrite content of the dendrites depends on the nickel content and base composition of the iron-based hardfacing alloy. The amount of ferrite in the dendrites is shown to have a significant influence on the hardness and galling wear resistance, as determined using ASTM G98 methods. Fracture-toughness (K _IC) testing in accordance with ASTM E399 methods was used to quantify the damage tolerance of various iron-based hardfacing alloys. Fractographic and microstructure examinations were used to determine the influence of microstructure on the wear resistance and fracture toughness of the iron-based hardfacing alloys. A crack-bridging toughening model was shown to describe the influence of ferrite content on the fracture toughness. A higher ferrite content in the dendrites of an iron-based hardfacing alloy reduces the tendency for plastic stretching and necking of the dendrites, which results in improved wear resistance, high hardness, and lower fracture-toughness values. A NOREM 02 hardfacing alloy has the most-optimum ferrite content, which results in the most-desired balance of galling resistance and high K _IC values.     

Applications for plasma transferred arc welded tools during hot steel tube making

Abstract

This paper describes applications of a tool reinforcement technology, using plasma transferred arc (PTA) welding, in hot metal rolling. The coating of large NbC particles shows a remarkable performance in the suppression of galling. As the rolling temperature increases, a matrix material with high temperature resistance to deformation is recommended. The tool life is slightly longer when a thick scale layer exists on the hot metal surface, but when the scale is eliminated the new tool demonstrates excellent capability. The new tool also shows a higher level of performance when rolling hot titanium and hot stainless steel. The application philosophy of PTA welded tools is demonstrated.     

BG-SG特殊螺纹接头结构参数对密封性能的影响

BG-SG特殊螺纹接头是一种针对国内页岩气井专门开发的特殊螺纹接头形式,主要由锥面/锥面主密封结构、直角扭矩台肩结构和双段式螺纹连接部分组成,具有高连接强度、高抗扭等优点,适用于大狗腿度下的复杂井况。基于控制变量法的思想,运用有限元数值仿真计算方法分别研究了密封面过盈量(δ)、密封面长度(l)和密封面锥度(ΔD/L)等三个结构参数对接头密封接触压力分布和密封性能的影响。分析结果表明,δ的增大对接头密封性能有正面影响,但过大的过盈量并不能持续增加有效接触长度,且需控制其值不致引起接头结构的塑性变形或黏结;增加l值,可一定程度上增加密封面的有效接触长度,但超过某个特定长度以后则会在密封面中部产生零接触应力区域;ΔD/L对密封面两侧接触点附近的影响有所不同。根据分析结果优化设计了各结构参数,所开发接头顺利通过实物性能试验,验证了有限元分析的有效性。     

Development and application of a new hot-work die steel for hot stamping

A new hot-work die steel for hot stamping was developed, and used the die for mass production. The produced die showed good performance owing to its high heat conductivity and wear-resistant characteristics. Two different benchmarking hot-work die steels were investigated, and then compared in terms of their impact ductility,temper characteristics, heat conductivity, and thermal stability. The result of the high-temperature friction wear test indicated that oxidative wear was the main mode in high temperature. On the basis of the comparison and test results, the alloying composition of the new hot-work die steel was especially designed. The new die steel showed good performance with good wear-resistant quality, as well as temper hardness and heat conductivity of HRC 50 and34.3 W/(m·K), respectively. Furthermore,without surface plasma nitriding, the die made of the new steel had no obvious galling with 6142 strokes. After surface plasma nitriding, the die completed 40000 strokes with good surface. The die life is expected to exceed 200000 strokes.