空心抽油杆摩擦焊接头强韧性探讨

本文对２０ＣｒＭｏ＋３５ＣｒＭｏ空心抽油杆摩擦焊接头采用局部中频感应加势顺火热处理工艺，通过对摩擦焊接及焊后回火热处理工艺的优化，提高了接头的强韧性，使焊缝区的σｂ，σｓ超过了ＳＹ５５５０－９２空心抽油杆规定的Ｄ级杆的标准要求。     

摩擦焊接头热影响区晶粒特征的研究

采用摩擦焊后水淬和空冷的方法研究了２０ＣｒＭｏ＋３５ＣｒＭｏ摩擦焊接头热影响区晶粒状态及其影响因素。研究结果表明，摩擦焊接头近缝区处于动态再结晶状态。分析了其晶粒尺寸与Ｚｅｎｅｒ－Ｈｏｌｌｏｍｏｎ因子的关系，指出强工艺规范可使晶粒细化，使焊缝韧性提高。     

16Co14Ni10Cr2MoA超高强度钢焊接接头组织和性能的研究

介绍了１６Ｃｏ１４Ｎｉ１０Ｃｒ２ＭｏＡ超高强度钢氩弧焊接头的力学性能，与４０ＣｒＭｎＳｉＭｏＶＡ超高强度钢的焊接接头作了对比分析，并借助金相和电镜对接头组织进行了分析。结果表明，该超高强钢的焊接性良好，不仅接头强度高，而且塑性和韧性仍保持很高水平。     

1Cr5Mo钢管道焊后热处理质量评定指标研究

以１Ｃｒ５Ｍｏ钢管道为例,讨论了焊后热处理质量评定指标,通过对实际接头不同热处理制度下及热处理前后残余应力,硬度的测定和显微组织的观察,认为对于１Ｃｒ５Ｍｏ钢,以接头的硬度最大值２２５ＨＢ作为热处理质量评定指标较为恰当。在焊接质量保证合格的前提下,一般可仅校验热处理温度记录曲线合格,判定热处理质量合格。     

Cr5Mo铸钢的碳含量与组织和性能的关系

研究了Ｃｒ５Ｍｏ 铸钢的碳含量与组织和性能之间的关系。依据试验结果,对照ＳＹＢ１５１０２－ ６３标准对性能的要求,详细探讨了碳含量以及热处理工艺对Ｃｒ５Ｍｏ 铸钢组织和性能影响的规律,给出了合理的碳含量范围和热处理工艺。     

10CrNi4MoV钢厚板的热处理工艺及其组织与性能

本文探索了１０ＣｒＮｉ４ＭｏＶ钢１００ｍｍ特厚板适宜的热处理工艺,并对经热处理的钢板进行了性能测试及微观组织观察。结果表明：１０ＣｒＮｉ４ＭｏＶ钢１００ｍｍ特厚板经过严格控制的高温淬火＋高温回火调质工艺处理,可以满足技术要求,且在厚度方向上微观组织、力学性能均匀。高温淬火温度对厚板的组织性能影响不大,高温回火温度则必须严格控制,以获取１０ＣｒＮｉ４ＭｏＶ钢１００ｍｍ特厚板良好的综合性能。     

耐热钢管10CrMo910的焊接

本文分析了耐热钢管１０ＣｒＭｏ９１０的焊接工艺要点，对材料的焊接性和拟定的焊接工艺进行了试验研究，并介绍了现场焊接工艺过程。     

10Cr4Ni4Mo4V钢和Cr4Mo4V钢的特性与断裂行为

对１０Ｃｒ４Ｎｉ４Ｍｏ４Ｖ钢和Ｃｒ４Ｍｏ４Ｖ钢的特性与断裂行为进行了试验研究。结果表明,１０Ｃｒ４Ｎｉ４Ｍｏ４Ｖ钢经微氮渗碳热处理后,其表面硬度、残余应力、断裂韧性及裂纹扩展速率均优于Ｃｒ４Ｍｏ４Ｖ钢的。     

Crl2MoV钢渗碳等温淬火组织分析EI

Ｃｒ１２ＭｏＶ钢采用渗碳及等温淬火处理后，获得了良好的力学性能和使用效果。采用ＴＥＭ和ＳＥＭ对此工艺处理后的Ｃｒ１２ＭｏＶ钢的渗层及心部组织形态进行观察分析，确定了心部贝氏体的形态；而渗层内在等温后期形成的特殊黑色针状组织，在该钢种的其他热处理方式中均不存在，不具备典型下贝氏体特征。本文为该钢种采用渗碳加等温淬火这种新的强化途径提供理论基础。     

Crl2MoV钢渗碳等温淬火组织分析

Ｃｒ１２ＭｏＶ钢采用渗碳及等温淬火处理后，获得了良好的力学性能和使用效果。采用ＴＥＭ和ＳＥＭ对此工艺处理后的Ｃｒ１２ＭｏＶ钢的渗层及心部组织形态进行观察分析，确定了心部贝氏体的形态；而渗层内在等温后期形成的特殊黑色针状组织，在该钢种的其他热处理方式中均不存在，不具备典型下贝氏体特征。本文为该钢种采用渗碳加等温淬火这种新的强化途径提供理论基础。     

同种材质与异种材质摩擦焊接头焊缝冲击韧性的研究

研究了低合金结构钢35CrMo同种材质和20CrMo 35CrMo，37Mn5 35CrMo异种材质摩擦焊接头的焊缝韧性，通过扫描电子显微镜和金相的方法深入研究了异种材质摩擦焊焊缝韧性低的原因。指出在合理的工艺规范下35CrMo同种材质的接头可获得结合良好、细小的等轴晶粒，从而使焊缝韧性提高。     

Metallurgical characterization of pulsed current gas tungsten arc,friction stir and laser beam welded AZ31B magnesium alloy joints

This paper reports the influences of welding processes such as friction stir welding (FSW), laser beam welding (LBW) and pulsed current gas tungsten arc welding (PCGTAW) on mechanical and metallurgical properties of AZ31B magnesium alloy. Optical microscopy, scanning electron microscopy, transmission electron microscopy and X-Ray diffraction technique were used to evaluate the metallurgical characteristics of welded joints. LBW joints exhibited superior tensile properties compared to FSW and PCGTAW joints due to the formation of finer grains in weld region, higher fusion zone hardness, the absence of heat affected zone, presence of uniformly distributed finer precipitates in weld region.     

Friction Stir Weldabilities of AA1050-H24 and AA6061-T6 Aluminum Alloys

The friction stir weldabilities of the strain-hardened AA1050-H24 and precipitate-hardened AA6061-T6 aluminum alloys were examined to reveal the effects of material properties on the friction stir welding behavior. The experimental results are obtlained. (1) For AA1050-H24, the weld can possess smoother surface ripples; there is no elliptical weld nugget in the weld; there is no discernible interface between the stir zone and the thermomechanically affected zone; and the internal defect of the weld looks like a long crack and is located in the lower part of the weld. (2) For AA6061-T6, the weld usually possesses slightly rougher surface ripples; an elliptical weld nugget clearly exists in the weld; there are discernible interfaces among the weld nugget, thermomechanically affected zone and heat affected zone; and the internal defect of the weld is similar to that of the AA1050-H24 weld. (3) The effective range of welding parameters for AA1050-H24 is narrow, while the one for AA6061-T6 is very wide. (4) T     

Effect of welding parameters on microstructure and mechanical properties of friction stir welded joints of AA7039 aluminum alloy

A high strength Al–Zn–Mg alloy AA7039 was friction stir welded by varying welding and rotary speed of the tool in order to investigate the effect of varying welding parameters on microstructure and mechanical properties. The friction stir welding (FSW) process parameters have great influence on heat input per unit length of weld, hence on temperature profile which in turn governs the microstructure and mechanical properties of welded joints. There exits an optimum combination of welding and rotary speed to produce a sound and defect free joint with microstructure that yields maximum mechanical properties. The mechanical properties increase with decreasing welding speed/ increasing rotary speed i.e. with increasing heat input per unit length of welded joint. The high heat input joints fractured from heat affected zone (HAZ) adjacent to thermo-mechanically affected zone (TMAZ) on advancing side while low heat input joints fractured from weld nugget along zigzag line on advancing side.     

焊接速度对 7A52 铝合金 FSW 组织及力学性能的影响

目的在保证搅拌速度一定时,针对8 mm厚的7A52铝合金,在不同焊接速度下采用搅拌摩擦焊(FSW)进行焊接试验,研究其焊接接头的显微组织及力学性能。方法利用搅拌摩擦焊机进行对接焊接,焊后制取金相试样观察焊接接头宏观形貌和显微组织,并测定其力学性能。结果7A52铝合金FSW焊接接头焊核区的面积随着焊接速度的增大而增大,当焊接速度为250mm/min时,焊接接头的焊核区面积最大,焊核区的显微组织都为细小的等轴晶,焊接接头横截面的焊核区呈明显"洋葱环"的形貌,而热力影响区的结构特征则呈现出了较高的塑性变形流线层。焊接接头显微硬度分布都呈现出"W"形变化,在焊接速度为150 mm/min时,焊接接头的平均抗拉强度能达到452 MPa,达到了母材抗拉强度的89%。结论通过对不同焊接速度下7A52铝合金FSW焊接接头的组织和性能进行研究,得到了不同焊接速度下焊接接头组织和力学性能。     

Improvement of weld temperature distribution and mechanical properties of 7050 aluminum alloy butt joints by submerged friction stir welding

Submerged friction stir welding (FSW) in cold and hot water, as well as in air, was carried out for 7050 aluminum alloys. The weld thermal cycles and transverse distributions of the microhardness of the weld joints were measured, and their tensile properties were tested. The fracture surfaces of the tensile specimens were observed, and the microstructures at the fracture region were investigated. The results show that the peak temperature during welding in air was up to 380 °C, while the peak temperatures during welding in cold and hot water were about 220 and 300 °C, respectively. The temperature at the retreated side of the joint was higher than that at the advanced side for all weld joints. The distributions of microhardness exhibited a typical “W” shape. The width of the low hardness zone varied with the weld ambient conditions. The minimum hardness zone was located at the heat affected zone (HAZ) of the weld joints. Better tensile properties were achieved for joint welded in hot water, and the strength ratio of the weld joint to the base metal was up to 92%. The tensile fracture position was located at the low hardness zone of the weld joints. The fracture surfaces exhibited a mixture of dimples and quasi-cleavage planes for the joints welded in cold and hot water, and only dimples for the joint welded in air.     

Evaluation of the microstructure and mechanical properties of friction stir welded 6005 aluminum alloy

Abstract

The microstructural change related with the hardness profile has been evaluated for friction stir welded, age hardenable 6005 Al alloy. Frictional heat and plastic flow during friction stir welding created fine and equiaxed grains in the stir zone (SZ), and elongated and recovered grains in the thermomechanically affected zone (TMAZ). The heat affected zone (HAZ), identified only by the hardness result because there is no difference in grain structure compared to the base metal, was formed beside the weld zone. A softened region was formed near the weld zone during the friction stir welding process. The softened region was characterised by the dissolution and coarsening of the strengthening precipitate during friction stir welding. Sound joints in 6005 Al alloys were successfully formed under a wide range of friction stir welding conditions. The maximum tensile strength, obtained at 507 mm min^-1 welding speed and 1600 rev min^-1 tool rotation speed, was 220 MPa, which was 85% of the strength of the base metal.     

电场对异种金属摩擦焊接头组织与性能的影响

研究了外加电场对T2紫铜和1Cr18Ni9Ti不锈钢摩擦焊接头焊合区的显微组织、主要合金元素的扩散区宽度以及接头力学性能的影响．结果表明，外加电场加快了焊合区金属的动态再结品进程，不同形式的电场对焊合区铜侧的组织形态与分布有不同的影响．在负电场(试件接电源负极)作用下，焊合区金厦发生的动态再结晶程度最大，品粒尺寸较大且分布均匀；交流电场使品粒尺寸略有减小．交流电场和负电场通过对金厦内部电子密度的影响，促进了焊接过程中焊缝区Cu、Pe和Cr的扩散，并提高了焊接接头扭转强度。     

Identification of the pin offset effect on the friction stir welding (FSW) via Taguchi – Grey relational analysis: A Case study for AA 7075 – AA 6013 alloys

The aim of this work is to present a case study relating to the dissimilar friction stir welding (FSW) ability of AA 7075‐T651 and AA 6013‐T6 by applying pin offset technique. An orthogonal array L18 was conducted to perform the overlapped weld seams using three different values of pin offset, welding speed and tool rotational speed along with two different pin profiles determine the impact of welding parameters on the tensile properties of friction stir welded joints. The nugget zone for each of overlapped weld seams exhibited a complex structure and also, the pin offset and profile also were found to have a great impact on the microstructural evolution of the nugget zone. The ultimate tensile strength, elongation at the rapture and bending strength of welded joints were measured in the ranges of 194–215 MPa, 1.79–3.34 % and 203–352 MPa. From the Taguchi based Grey relational analysis, the optimum welding condition was determined for the welded joint performed using a single fluted pin profile with the zero pin offset, tool rotational speed of 630 min^?1 and welding speed of 63 mm/min. Microstructural and macro‐structural observations revealed that welded joints exhibiting lower tensile strength are consistent of various types of defects (e. g. cracks, tunnels and cavities). The fracture location of welded joints was found to be on the heat affected zone and between the heat affected zone and AA 6013‐base metal. The tool and pin wear was not observed during the welding applications     

Effect of Process Parameters on Tensile Strength of Friction Stir Welded Cast LM6 Aluminium Alloy Joints

This paper reports the effect of friction stir welding(FSW)process parameters on tensile strength of cast LM6 aluminium alloy.Joints were made by using dierent combinations of tool rotation speed,welding speed and axial force each at four levels.The quality of weld zone was investigated using macrostructure and microstructure analysis.Tensile strength of the joints were evaluated and correlated with the weld zone hardness and microstructure.The joint fabricated using a rotational speed of 900 r/min,a weldin...