回火处理对高碳冷拔钢丝强度和塑性的影响

研究了６５钢冷拔钢丝在５００℃不同时间回火时的抗拉强度和延伸率的变化。试验结果发现，在回火初期，抗拉强度首先增长，然后随口火时间的延长连续降低，而延伸率始终在增长，增长速度是先快后慢。这种行为可归因于第一内应力的消除和ε－碳化物在形变铁素体中的析出以及后来再结晶的发生。     

大口径方管排辊成形工艺的仿真分析

针对四道次滚模压制大口径方形管成形工艺，采用有限元仿真软件ANSYS／DYNA对冷拔、推挤和滚轧进行仿真和比较分析，揭示各工艺成形的形状变形特点和作用力变化规律，为优选成型工艺参数提供了基础。     

65Mn热轧盘条冷拉模裂原因分析

对冷拉过程中产生黄裂的６５Ｍｎ弹簧钢丝进行了金相、扫描电镜和电子探针分析。结果表明，横裂原因为盘条碳成份偏析，使组织产生明显的区域性差异，致使金条在拉拔时形变不协调而产生横裂。     

冷拔内直筋管凸筋拉缩的研究

根据凸筋拉缩变形的力学条件,研究了工艺因素对凸筋拉缩的影响规律。采用多元非线性曲线拟合的方法,建立了凸筋拉缩的数学模型,可用于凸筋拉缩量的预测及管坯规格的选择。     

Optimisation of post-drawing treatments by means of neutron diffraction

The mechanical properties and the durability of cold-drawn eutectoid wires (especially in aggressive environments) are influenced by the residual stresses generated during the drawing process. Steelmakers have devised procedures (thermomechanical treatments after drawing) attempting to relieve them in order to improve wire performance. In this work neutron diffraction measurements have been used to ascertain the role of temperature and applied force – during post-drawing treatments – on the residual stresses of five rod batches with different treatments. The results show that conventional thermomechanical treatments are successful in relieving the residual stresses created by cold-drawing, although these procedures can be improved by changing the temperature or the stretching force. Knowledge of the residual stress profiles after these changes is a useful tool to improve the thermomechanical treatments instead of the empirical procedures used currently.     

高精度小直径无缝钢管生产工艺改进

分析了传统的大直径定壁冷拔工艺生产高精度小直径无缝钢管的弊端，提出了小直径定壁冷拔新工艺和新顶头结构。实践表明，新工艺生产的高精度小直径无缝钢管，其尺寸精度、表面质量均达到技术要求。     

冷拔管机负荷率的现场计算

介绍了冷拔管机负荷率现场计算方法和应用实例。     

双相钢在冷拔单体液压支柱缸筒中的应用

介绍了双相钢的特征，分析了其性能优良的原因，比较了１０ＭｎＳｉ双相钢和２７ＳｉＭｎ低合金高强度钢的σ－ε曲线，钢和冷拔管的机械性能及工艺性能等。结果表明，双相钢适合冷拔制造液压支柱缸筒，其综合经济效益较好。     

Enhancing high-cycle fatigue properties of cold-drawn Fe–Mn–C TWIP steels

High-cycle fatigue properties of cold-drawn twinning-induced plasticity (TWIP) steel, a favored candidate for replacing fully pearlitic (FP) steels in wire applications, were investigated. The high-cycle fatigue tests were conducted on cold-drawn TWIP and FP steels that had comparable ultimate tensile strength for comparison. Fatigue strength of both TWIP and FP steels increased with the tensile strength, but the TWIP steel cold-drawn to a tensile strength of 1.5 GPa exhibited a very low fatigue ratio (a ratio of fatigue strength to tensile strength) which deviated far from the predicted linear relationship. Fracture surface analysis showed that crack initiation mainly occurred at the ferrite matrix in FP steels, while either at grain or twin boundaries in TWIP steels where a large density of dislocations piled up during cold drawing. In the case of TWIP steels, the presence of inclusions at grain boundaries led to high local stress concentration and caused early intergranular fatigue cracking as notch sensitivity increased with tensile strength. Subsequent annealing after cold-drawing effectively increased fatigue strength of TWIP steels. It was suggested that TWIP steel revealing both high tensile strength and excellent high cycle fatigue strength could be a promising alternative for replacing conventional FP steels.     

钢管冷拔内模固体渗硼试验研究

内模是冷拔钢管的主要工模具之一．传统的内模金属表面渗碳镀铬技术是目前国内相关生产企业采用最多的一种原始加工工艺,其缺点是废液排放对环境污染比较严重。介绍了一种对加工后内模表面进行固体渗硼的新工艺,该工艺不仅可提高内模的使用寿命和生产率,降低成本,而且可改善环境污染问题。