薄壁不锈钢零件冷风加工探讨

针对不锈钢制做的薄壁测试模型的难切削性,采用了冷风切削加工技术。实验结果表明,这种方法能够加工出达到测试模型要求的零件。冷风切削不锈钢的实验成功,为航空实验水平上台阶,创造了条件。     

不锈钢切削加工的研究

为解决不锈钢加工困难的问题,从选择刀具材料、刀具角度和切削用量三方面对不锈钢的切削加工进行了分析和研究。     

干式、半干式和低温冷风切削加工技术

切削热是伴随金属切削过程中必然的一种物理现象,对工件质量、刀具寿命有不可忽视的影响。低速切削时,机械磨损是刀具磨损的主要原因;而高速切削时,切削高温诱导刀具的磨损,由机械磨损为主转化为扩散磨损、相变磨损和炭化磨损为主要磨损机理,并引发刀具表面的粘结磨损。切削热还使刀具和工件热膨胀,加剧后刀面摩擦与磨损,引起工件表面粗糙度上升,故超精加工工艺特别强调必须及时、有效地控制切削热在工件、刀具内的传导。控制刀具、工件温升对数控加工有十分重要的意义。 要控制金属的切削热及刀具、工件的温升,必     

奥氏全不锈钢的切削加工

本文通过ＤＹＪ４５－３００２１１活塞试生产介绍，总结００Ｃｒ１９Ｎｉ１１超低碳奥氏体不锈钢的切削特点，及在车削、钻削及攻丝时，如何合理选择刀具材料，刀具几何参数，机加工切削参数等，并总结如何通过冷却、热处理等技术方法改善奥氏全不锈钢的切削加工性能。     

铬镍不锈钢的切削加工

文章根据铬镍不锈钢的性能和特点，结合应用实例，介绍了铬镍不锈钢加工时各加工参数选择对加工的不同影响。     

不锈钢的切削加工

本刊上期介绍了不锈钢钻削加工中的一些值得注意的问题。这里介绍的是近年来不锈钢外圆切削、沟槽加工、小直径镗削加工、螺纹加工及切断加工的一些新进展。文中提到的刀具大都在国外展览会上作过切削表演,在刀具结构方面,针对不锈钢难于加工的特点,作了不少改进,加工效率和加工精度均有不同程度的提高。     

不锈钢丝锥切削加工的改进

提出了改进标准丝锥的几何参数及合理选择切削速度和切削液，以改善不锈钢丝锥切削加工性能。     

切削参数对不锈钢加工表面粗糙度的影响

通过切削试验研究了进给量、切削速度、刀具圆弧半径以及切屑形态等四个因素对不锈钢加工表面粗糙度的影响规律,确定了降低表面粗糙度的切削参数优化组合。     

冷风切削技术的发展应用及课题

在金属切削三个基本条件中,鉴于机床条件、刀具条件的进步,更显得改善冷却条件的重要;用低温空气代替切削剂,是改善冷却条件的新办法。本文简单介绍冷风切削技术的机理、冷风切削加工系统和冷风切削技术的应用。结合生产实践,从质量、效率及成本等用户最关心的问题进行了较详细的论述。并提出采用冷风切削技术进行新一代清洁化机床工具产品结构调整时应该研究的一些课题。     

不同表面处理对不锈钢SUS304耐微生物腐蚀性能的影响

对焊接的ＳＵＳ３０４不锈钢进行氧化、打磨、酸洗和喷丸等不同处理，研究了不同表面处理对ＳＵＳ３０４不锈钢耐微生物腐蚀性能的影响。在微生物腐蚀试验台中测量了不同表面的试样的开路电压，分析了不同表面处理对电位升的影响。测量了不同表面状态下ＳＵＳ３０４不锈钢的点蚀电位。用俄歇电子能谱（ＡＥＳ）对不同表面进行了分析。得出在不同表面状态下，ＳＵＳ３０４不锈钢耐微生物腐蚀性能由好到差依次是酸洗、喷丸、打磨、原样和氧化。     

MACHINING RESIDUAL STRESSES IN AISI 316L STEEL AND THEIR CORRELATION WITH THE CUTTING PARAMETERS

It is well known that machining results in residual stresses in the workpiece. These stresses correlate very closely with the cutting tool geometrical parameters as well as with the machining regime. This paper studies the residual stress induced in turning of AISI 316L steel. Particular attention is paid to the influence of the cutting parameters, such as the cutting speed, feed and depth of cut. In the experiments, the residual stresses have been measured using the X-ray diffraction technique (at the surface of the workpiece and in depth). The effects of cutting conditions on residual stresses are analyzed in association with the experimentally determined cutting forces. The orthogonal components of the cutting force were measured using a piezoelectric dynamometer.     

MICROBIOLOGICALLY INFLUENCED CORROSION ON WELD OF STAINLESS STEEL 304L

ＭＩＣＲＯＢＩＯＬＯＧＩＣＡＬＬＹＩＮＦＬＵＥＮＣＥＤＣＯＲＲＯＳＩＯＮＯＮＷＥＬＤＯＦＳＴＡＩＮＬＥＳＳＳＴＥＥＬ３０４ＬＣｈｅｎＺｈｉｇａｎｇＪｉａｎｇｓｕＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇｙＧｕｅｍｐｅｌＰ．Ｋａｅｓ...     

微量润滑油润滑和冷风冷却加工法对高硅铝合金切削面的影响

由于高硅铝合金中含有大量硅结晶粒子,硬度较大的硅结晶粒子在切削中会加速刀具的磨损,所以,其被切削性非常不好。为解决这一问题,以往是使用大量切削油进行切削加工。但是,随着环境意识的提高,大量切削油的使用所造成的环境污染的问题不得不被认识并进行改变。使用对切削点进行微量植物性润滑油润滑和冷风冷却的方法进行研究,探讨对高硅铝合金切削面的影响。并因此探讨半干式切削加工的可行性。     

CUTTING TEMPERATURE OF TEMPERING BEARING STEEL GCr15 CUT BY PCBN CUTTER

０　ＩＮＴＲＯＤＵＣＴＩＯＮＰＣＢＮ（Ｐｏｌｙｃｒｙｓｔａｌｌｉｎｅｃｕｂｉｃｂｏｒｏｎｎｉｔｒｉｄｅ）ｃｕｔｔｅｒｓｈａｖｅｂｅｅｎｕｓｅｄｉｎｍａｃｈｉｎｉｎｇｆｏｒｔｗｅｎｔｙｙｅａｒｓｓｉｎｃｅｔｈｅｙｗｅｒｅｓｕｃｃｅｓｓｆｕｌｌｙｄｅｖｅｌｏｐｅｄｉｎｔｈｅ１９７０’ｓ．Ｆｏｒｈａｖｉｎｇｇｏｏｄｃｕｔｔｉｎｇｐｒｏｐｅｒｔｉｅｓ,ｔｈｅｙｒｅｃｅｉｖｅｄｗｉｄｅｌｙａｔｔｅｎｔｉｏｎ．ＭａｎｙｆａｃｔｏｒｉｅｓｄｅｖｅｌｏｐｅｄｍａｎｙｋｉｎｄｓｏｆＰＣＢＮｐｒｏｄｕｃｔｓｗｈｉｃ…     

IMPROVEMENTS IN THE SURFACE CHARACTERISTICS OF STAINLESS STEEL WORKPIECES BY BURNISHING WITH AN AMORPHOUS DIAMOND-COATED TIP

Burnishing is a cold working process that can be used to improve surface finish and surface hardness of workpieces. Conventionally, diamond or hard metal burnishing tools are used. In the present work, a novel burnishing tool was created by depositing amorphous diamond coating (AD) on a stainless steel tip. This tool was used to improve the surface finish and surface hardness of Nitronic-50 HS stainless steel workpieces. Nitronic-50 HS is used in a wide range of applications in industry. The burnishing process was carried out at different burnishing parameters (force, revolution speed, feed and number of tool passes). Burnishing parameters had a significant effect on the finishing process and they had to be optimized to achieve the best results. Remarkable improvements in surface finish (70% decrease in roughness) and hardness (25% increase) could be achieved with this tool and process in the surface finishing of Nitronic-50 stainless steel workpieces. From the tribological point of view, the AD-coated tip performed slightly better than a corresponding tip modified from a commercial polycrystalline diamond tip. AD coating seems to be very suitable for use in mechanical surface finishing tools such as a burnishing tip.     

THE EFFECT OF THE CUTTING FLUID ON SURFACE ROUGHNESS IN BORING OF LOW CARBON STEEL-TECHNICAL COMMUNICATION

In spite of their environmental and human health problems, the cutting fluids still have been used widely in industry due to cutting fluid application can increase cutting performance in metal cutting. In this article, the effect of the cutting fluid on surface roughness in boring of AISI 1030 low carbon steel was investigated depending on BUE and chip formations and other cutting parameters, such as cutting speed, feed rate and tool nose radius. In most of boring experiments, the wet cutting did not show more preferable results than dry cutting. However, cutting fluid application with big nose radius and small feed rate improved the surface roughness up to 80%. This progress was attributed to a favorable chip formation as much as effective cooling.     

OPTIMIZATION STUDIES ON HOLE-MAKING TOOLS FOR HIGH-PERFORMANCE CUTTING AUSTENITIC STAINLESS STEEL

Austenitic stainless steel is a kind of difficult-to-cut material utilized widely in various industry fields. Hole-making tools are the uppermost obstacle of high performance cutting, so the optimizations of tools are imperative. This paper presents respectively the optimal geometrical characteristics and corresponding coating for high performance cutting austenitic stainless steel. The appreciated cutting performance of optimized tools with optimized cutting parameters has also been evaluated completely through experiments. Optimized special drills with point angle 138° and helix angle 38° was decided and TiCN coating was selected as the best coating. However optimized taps had different geometry structures for tapping through holes and blind holes. The former adopted the spiral pointed tap with inclination angle 15 °. The latter was spiral fluted tap with helix angle 34°. In high-performance cutting austenitic stainless steel, the optimized cutting parameters of special drills are 16 m/min and 0.13 mm/rev. The research results will be of great benefit for the development and application of high efficient and precise drills and taps of high performance cutting austenitic stainless steel.     

OPTIMIZATION STUDIES ON HOLE-MAKING TOOLS FOR HIGH-PERFORMANCE CUTTING AUSTENITIC STAINLESS STEEL

Austenitic stainless steel is a kind of difficult-to-cut material utilized widely in various industry fields. Hole-making tools are the uppermost obstacle of high performance cutting, so the optimizations of tools are imperative. This paper presents respectively the optimal geometrical characteristics and corresponding coating for high performance cutting austenitic stainless steel. The appreciated cutting performance of optimized tools with optimized cutting parameters has also been evaluated completely through experiments. Optimized special drills with point angle 138° and helix angle 38° was decided and TiCN coating was selected as the best coating. However optimized taps had different geometry structures for tapping through holes and blind holes. The former adopted the spiral pointed tap with inclination angle 15 °. The latter was spiral fluted tap with helix angle 34°. In high-performance cutting austenitic stainless steel, the optimized cutting parameters of special drills are 16 m/min and 0.13 mm/rev. The research results will be of great benefit for the development and application of high efficient and precise drills and taps of high performance cutting austenitic stainless steel.     

MACHINING OF CORTICAL BONE: SURFACE TEXTURE,SURFACE INTEGRITY AND CUTTING FORCES

Cutting, drilling and reaming of human bone are conducted in total joint replacement procedures and the placement of dental implants. In the current study orthogonal machining of cortical bone was performed and the cutting and thrust forces, as well as the machined surface quality, were evaluated over a range of osteon orientations and cutting conditions. Results showed that cutting perpendicular to the osteons resulted in the highest machining forces, largest surface roughness and extensive sub-surface damage for some parametric conditions. The average surface roughness of the machined bone ranged from 1 μm to over 70 μm, was largest for positive rake angle tools and increased with the depth of cut. There was no correlation between the cutting forces and machined surface quality. While negative rake angle tools resulted in the largest cutting forces, they provided the lowest surface roughness and highest apparent surface quality. Overall, the results show that orthogonal cutting of bone can result in near-surface damage that reduces the degree of contact between bone and implanted devices and is potentially detrimental to the post-surgical recovery rate.