Fe—Cr—Al合金冷轧及冷拔工艺性研究

通过对Ｆｅ－Ｃｒ－Ａｌ合金冷轧,冷拨试样的,对影响Ｆｅ－Ｃｒ－Ａｌ合金冷轧及冷拔工艺性的有关因素,如材料塑性、加工理化、应力状态等进行了研究,并对冷轧及冷拔Ｆｅ－Ｃｒ－Ａｌ合金的工艺性进行对比分析,研究结果表明,在Ｆｅ－Ｃｒ－Ａｌ合金丝的生产中,冷轧工艺优于冷拔工艺。     

21－4N钢生产工艺的改进

用冷轧代替冷拔生产２１－４Ｎ钢是一种新方法。通过冷轧２１－４Ｎ圆钢的实验得出：２１－４Ｎ圆钢经冷轧后断面椭圆度≤０．１ｍｍ，且沿轧件全长直径趋于均匀，达到冷拔的精度；采用工艺润滑可以进一步提高冷轧圆钢精度：经冷轧后组织中的析出相变小变多，且冷轧后强度和硬度增高，延伸率降低。     

21—4N钢生产工艺的改进

用冷轧代替冷拔生产２１－４Ｎ钢是一种新方法。通过冷轧２１－４Ｎ圆钢的实验得出：２１－４Ｎ圆钢经冷轧后断面椭圆度≤０．１ｍｍ，且沿轧件全长直径趋于均匀，达到冷拔的精度；采用工艺润滑可以进一步提高冷轧圆钢精度；经冷轧机后组织中的析出相变小变多，且冷轧后强度和硬度增高，延伸率降低。     

铁基形状记忆合金0Cr9Ni6Mn16Si5的生产工艺

研究了0Cr9Ni6Mnl6Si5形状记亿合金的生产工艺和性能。研究结果表明，0Cr9Ni6Mnl6Si5合金可以采用EF VOD VHD工艺冶炼。该合金具有强的热敏感性和高温变形抗力，高温可加工热塑性温度区间比较窄，温度超过l100℃时塑性直线下降。铸锭的开锻温度为l080℃，终锻温度为900℃；锻造管坯只有采用挤压方法实施管材成形。挤压成形的毛坯管可以采用冷轧与冷拔相结合的方法进一步加工成薄壁管。     

7001铝合金薄壁管材工艺研究

研究了7001超硬铝合金薄壁管的加工工艺。结果表明,Al-Zn-Mg-Cu系的7001合金具有相对较好的冷加工性能,在一定工艺条件下完全可以生产薄壁管材,但应严格控制冷加工变形量。管材冷轧时的道次变形量控制在50%～60%,冷拔时的道次加工率不要超过30%。     

冷加工对CN-1515奥氏体不锈钢包壳管亚结构的影响

通过透射电镜（TEM）和背散射电子衍射（EBSD）对冷加工后CN-1515奥氏体不锈钢包壳管亚结构的演变规律进行研究。结果表明，随着冷轧变形量的提高，退火孪晶减少，形变孪晶数量逐渐增大，孪晶宽度和孪晶间距不断变小，孪晶宽度由变形量为15%时的0.03～0.043μm减小到25%时的<0.02μm，而位错胞的尺寸则呈现先变大后变小的趋势。另外，冷轧工艺条件下，形变孪晶的形态也是一直保持平直，冷拔时出现孪晶界的弯折。在相同变形量下，冷拔比冷轧会产生更多的形变孪晶。     

Φ50二辊斜轧穿孔机抱辊装置的改进

我厂生产冷拔冷轧薄壁小直径管及毛管,经过二十年的完善和发展,已形成了年产6000多吨冷拔冷轧碳钢管及不锈钢管的生产能力。     

铜管生产的工艺及其特点

介绍了四种铜管生产工艺、即低挤压比挤压－冷轧－拉伸；高挤压比挤压－拉伸；横轧穿孔－冷轧－拉伸；空心管坯连铸－冷轧－拉伸。阐述了四种工艺的特点及适宜生产的管材类型。     

超低碳不锈钢HR-1挤压管试制工艺研讨

超低碳奥氏体不锈钢00Cr17Ni14M02（HR-1）具有较高的附加值,钢管公司挤压车间首次试制HR-1小规格厚壁管,通过挤压＋冷拔两次试制的研究,最终生产出了符合标准的HR-1挤压无缝管,并为今后生产同类小规格厚壁管积累了宝贵的生产经验。     

5056合金薄壁管冷加工工艺研究

研究了5056合金薄壁管的冷加工性能及退火制度对其冷加工性能的影响。结果表明，与5A05、5A06等高镁铝合金相比，5056合金薄壁管冷加工时的道次加工率大，冷轧时可达70％左右，冷拔时达20％以上，两次退火同总的冷拔变形量可达30％以上；对于由热挤压提供的管坯，在冷轧前可不进行坯料退火；冷加工管材的表面质量好，不易出现裂纹、裂12等缺陷。通过实验，确定了合理的冷加工生产工艺。     

980 MPa级冷轧超高强度双相钢边裂原因分析与工艺优化

汽车用超高强度双相钢CR550/980DP冷轧边裂问题,严重影响热轧/冷轧工序界面生产顺行,易造成冷轧机架间及连退炉内断带事故,成为超高强度双相钢生产的难题。基于高温热塑性曲线和热轧动态CCT曲线,采用对显微组织、力学性能、裂纹扩展分析等手段明确冷轧边裂产生原因。试验结果分别指出,精轧阶段带钢横向温度分布不均匀、边部温降大,导致在第Ⅲ脆性区轧制;同时,受Nb作用再结晶温度提高,边部低温区为未再结晶区轧制;当应变量超过塑性极限、轧制力超过边部热强度时,形成热轧卷边裂。边部形成细小弥散的铁素体(F)和马氏体(M)两相组织,不协调应变将导致F/M相界面产生应力集中而形成裂纹;裂纹以微孔聚集方式进行扩展,形成热轧卷无边裂-冷轧边裂现象。通过投用边部加热器和优化初轧定宽量、精轧入口温度、精轧机架间冷却水、终轧温度、卷取温度等措施,实现热轧卷边部质量改善、解决边裂问题。     

乘用车用钢管技术质量要求和生产工艺要点

乘用车用管应用部位广,有许多特殊要求,属于高级机械结构用管。介绍了乘用车几种典型的常规要求钢管、制管工艺及生产工艺要点。详细介绍了乘用车特殊要求钢管的技术质量要求、再加工、生产工艺流程,以及应用冷拔、冷轧工艺和材质控制等生产满足不同要求的钢管产品。阐述了汽车用钢管开发的机遇与挑战,提出了汽车用钢管需要以其专业化生产和特有的高技术含量、高附加值来弥补规模化的不足。     

980 MPa级冷轧超高强度双相钢边裂原因分析与工艺优化

汽车用超高强度双相钢CR550/980DP冷轧边裂问题,严重影响热轧/冷轧工序界面生产顺行,易造成冷轧机架间及连退炉内断带事故,成为超高强度双相钢生产的难题。基于高温热塑性曲线和热轧动态CCT曲线,采用对显微组织、力学性能、裂纹扩展分析等手段明确冷轧边裂产生原因。试验结果分别指出,精轧阶段带钢横向温度分布不均匀、边部温降大,导致在第Ⅲ脆性区轧制;同时,受Nb作用再结晶温度提高,边部低温区为未再结晶区轧制;当应变量超过塑性极限、轧制力超过边部热强度时,形成热轧卷边裂。边部形成细小弥散的铁素体(F)和马氏体(M)两相组织,不协调应变将导致F/M相界面产生应力集中而形成裂纹;裂纹以微孔聚集方式进行扩展,形成热轧卷无边裂-冷轧边裂现象。通过投用边部加热器和优化初轧定宽量、精轧入口温度、精轧机架间冷却水、终轧温度、卷取温度等措施,实现热轧卷边部质量改善、解决边裂问题。     

石油行业用TA18钛合金厚壁管材的研制

石油行业用TA18钛合金厚壁管材的轧制难度较大,易出现表面开裂等现象,为此提出了2种不同冷轧工艺并对其轧制过程及效果进行了对比。此外,还研究了退火温度对管材性能和组织的影响。结果表明：采用两辊冷轧配合热矫直方法,可以缩短生产周期,提高生产效率,最终获得室温力学性能满足客户指标要求的TA18厚壁管材,且平直度可以达到0．75mm／m左右,内表面粗糙度平均为0．864μm。     

Neutron Stress Imaging of Drawn Copper Tube: Comparison with Finite-Element Model

Seamless tubes are used for various mechanical applications, often produced by several cold drawing steps to reach the required dimensions. The first process step, for example, extrusion or rolling, typically results in ovality and eccentricity of the tube caused by nonsymmetric material flow and being present during the cold drawing process, i.e., no homogeneous deformation. Because of this nonsymmetrical deformation, and deviations over the length of the tube caused by moving tools, this process step generates inhomogeneous residual stresses. To understand the interconnection between geometrical changes in the tubes and the resulting residual stresses, the residual strain distribution in a copper tube was measured by neutron diffraction. The aim of this study is to evaluate residual stresses generated during cold drawing of copper tubes. This research comprises experimental measurements and numerical analysis. An industrially produced copper tube was cold drawn, and the profile of residual strain over circumference and across wall thickness was measured by neutron diffraction. In parallel, a three-dimensional finite-element model (FEM) was developed to calculate the residual macrostress state generated by the forming process. Good agreement between experimental results and numerical computations was obtained. This article is based on a presentation given in the symposium entitled “Neutron and X-Ray Studies for Probing Materials Behavior,” which occurred during the TMS Spring Meeting in New Orleans, LA, March 9–13, 2008, under the auspices of the National Science Foundation, TMS, the TMS Structural Materials Division, and the TMS Advanced Characterization, Testing, and Simulation Committee.     

5A06铝合金薄壁管材冷轧裂口成因与工艺措施研究

针对5A06合金薄壁管材在冷轧过程中产生裂口缺陷这一棘手问题,从挤压管坯料质量、管坯退火制度以及送料量等方面分析其产生原因,探讨防止或消除冷轧过程中产生裂口缺陷的方法.     

Monel400管材轧制缺陷产生原因分析

LG60轧机在轧制Monel400合金管材时,管材表面局部出现螺旋状缺陷。对轧机、工艺、工模具及管坯四个方面进行分析和实验,结果表明:成品管材的开裂主要是由穿孔制坯时留下来的凹型螺旋缺陷所引起。通过调整穿孔机的相关参数,管坯表面螺旋缺陷消失,成品管材的表面质量提高。     

Influence of residuals on the metallurgical features of low carbon steel grades

The increased recycling of scrap leads in conventional steels to an increased content of undesirable trace elements. When scrap is used for steel production, the influence of precipitate‐forming or solid solution hardening trace elements in particular on the process and use properties has to be taken into account. The influence exerted by the elements niobium, titanium, chromium and molybdenum has been studied on the example of unalloyed deep drawing steels which are mainly used for the manufacture of automobiles. The production process – beginning with continuous casting, through hot rolling, cold rolling down to annealing – was simulated experimentally in laboratory equipment, and in parallel with a continuous casting simulator, forming dilatometer and high temperature conductimeter. Light‐optical microscopy and the EBSP measurements were used to characterise the pertaining microstructures. The mechanical final characteristics were determined in tensile tests. The results relating to continuous casting illustrate the influence of trace elements on precipitation, cracking, hot ductility and the phase transition from austenite in ferrite. The work softening during the hot rolling depends on the nature and the precipitation state of the foreign elements. The interplay of coiling temperature, precipitation and annealing temperature influences the softening during the annealing after the cold rolling. It could be shown that a large part of this takes place during the recovery. The analysed trace elements influence the final characteristics via hardening and grain sizes.     

冷轧法生产高精度特殊钢型材

冷轧法生产的高精度钢材较冷拔法具有更好的表面质量、尺寸精度和高的收得率。用冷轧法生产特殊钢高精度型材代替冷拔法是今后的发展方向。     

电站锅炉用 TP347H 不锈钢无缝管工艺的开发

太钢采用铁水预处理+30 t电弧炉熔化合金钢水-75 t K-OBM-S吹炼-VOD处理-LF精炼-5．6 t铸锭开坯(或220 mm×220 mm铸坯)-Φ100 mm管坯穿孔-冷轧(冷拔)流程,生产了Φ38 mm×6．6 mm TP347H (1Cr19Ni11Nb)钢无缝管。结果表明,通过控制[O]≤30×10^-6、[H]≤3×10^-6、As≤0.003 0％、Pb、Sn、Sb、Bi分别≤0．001 0％以及钢中C含量0.06％～0.08％、Nb含量0．6％-0.8％,钢管具有优良的冷、热加工性能,其各项性能均满足ASME和GB标准的使用要求。