三辊微张减全长纵向壁厚不均影响因素探讨

1、 三辊微张减全长纵向壁厚不均影响因素探讨摘要:通过在三辊减径机上跟踪总结叠加比I,减径量D,D/S(径壁比)与纵向壁厚差的关系,合理确定工艺参数,使全长纵向壁厚差S<0.6mm,钢管实物质量及尺寸精度完全符合GB/T8162-1999标准要求.关键词:纵向壁厚不均 影响因素 探讨前言随着现在无缝管生产工艺的发展,微张减在无缝管生产中迅速推广,应用愈来愈广泛,但微张减主要缺陷之一是容易产生管端增厚,同时由于叠加比原因,产生张力,使钢管中间壁厚与两端壁厚相差较大,壁厚差甚至相差2mm,影响用户的对钢管的加工和使用.我公司新上十二架微张力三辊减径机,生产初期,由于工艺参数原因,导致全长壁厚不均

2、严重,影响产品形象.在生产中多次试验和总结,对全长纵向壁厚不均的影响因素作了分析和探讨,采用新的工艺参数,使钢管质量符合标准要求.一. 全长纵向壁厚不均与叠加比的关系壁厚变化量:=2*Zm*(V0-1)+(1-V0)/Zm(1-V0)-(2-V0)式中:V0=S0/D0从式中可以看出,减径前后壁厚变化量与张力系数关系极大,而张力系数与叠加比关系较大.从生产实验中可以得出叠加比I是影响纵向壁厚不均的一个重要因素.以125mm坯料,生产83*14规格为例:从实验数据可看出,叠加比I达到70%时,纵向壁厚差基本在0.5mm以内,当叠加比达100%时,纵向壁厚差达2.2mm.可见叠加比是影响壁厚差的一

3、个重要因素.当叠加比小于60%时,壁厚差变化不大.二. 纵向壁厚不均与绝对减径量的关系:以生产实际中的数据采集表:(主电机转速860转/分钟,叠加比I=70%)S0D0/S0DSDS1S2平均头S3S4平均中SD/D钢种125.291777.513.71412.913.413.1512.51312.750.418.06碳结144.535781.515.51814.715.415.0514.11514.550.522.09碳结144.535780.41516.914.215.414.81414.814.40.421.02碳结154.233382.215.518.715.516.115.814.6

4、15.8515.2250.57522.75碳结163.96888516.821.516.217.316.7515.716.816.250.525.29碳结105.17210.82110.211.510.8510.310.710.50.3529.17碳结124.257113201213.312.6512.212.7512.4750.17528.17碳结133.923173142213.214.8141313.913.450.5530.14碳结143.642972152113.81514.414.214.714.45-0.0529.17碳结124.57112.81712.313.112.712.5

5、1312.75-0.0523.94碳结105.470.51116.510.811.110.9510.711.110.90.0523.4碳结105.770.51113.510.911.211.0510.811.2110.0519.15碳结124.757112.81412.513.412.9512.512.912.70.2519.72碳结1257112.81112.513.51312.713.112.90.115.49碳结116.181880.512.512.512.312.512.412.212.512.350.0515.53合结125.666781.51313.512.9513.513.225

6、12.713.112.90.32516.56合结144.857186151814.1515.614.8513.514.814.150.720.93合结164.2588.51720.515.917.516.716.117.1516.6250.07523.16碳结98.555683.510.56.59.810.19.9259.49.99.650.2757.784碳结126.41678513.5812.413.112.7512.212.712.450.39.412碳结125.41678513.52012.313.312.81212.512.250.5523.53碳结1358714.52213.114

7、.213.6512.713.513.10.5525.29碳结154.33338516201516.215.614.715.515.10.523.53碳结125.833382131212.412.812.61212.512.250.3514.63碳结135.384684141413.413.913.6513.213.713.450.216.67碳结154.66678316.51315.416.315.8514.915.815.350.515.66碳结164.3758517.51516.317.216.7516.216.716.450.317.65碳结184.6111100201718.419.8

8、19.118.218.918.550.5517碳结20452221.2520.052120.5250.72520.19碳结223.7727104242121.823.322.5521.622.822.20.3520.19碳结223.7727104242121.9522.822.37521.0522.8521.950.42520.19碳结146.357110515.31614.715.31514.214.814.50.515.24碳结165.5625100.517.511.516.717.31716.21716.60.411.44碳结175.23539918.31016

9、.8518.617.72517.118.117.60.12510.1碳结184.944410119.51217.8519.618.72518.3518.918.6250.111.88碳结204.4510422152122.221.620.521.621.050.5514.42碳结164.759617.52016.317.71715.61716.30.720.83合结109.510211.5710.111.310.67510.410.910.650.0256.863合结127.9167104.513.59.512.412.812.612.3512.7512.550.059.091碳结146.78

10、5710415.2914.715.615.12514.615.3514.9750.158.654碳结165.937510416.8916.717.617.1516.317.216.750.48.654碳结138109137.412.213.212.67512.713.1512.925-0.256.789碳结1010.811211410.111.110.610.3510.8510.603.571碳结12911213.5412.113.112.612.451312.725-0.1253.571合结194.368495201219.219.819.519.2519.719.4750.02512.63

11、碳结9101009109.8510.410.19.59.859.6750.42510碳结126.6667101142112.713.513.112.312.712.50.620.79碳结165104172416.517.216.8516.416.916.650.223.08碳结108.3101121810.411.110.7510.310.410.350.417.82碳结108.310111.51810.611.210.910.4510.7510.60.317.82碳结126.9167100.513.517.512.11312.5512.3512.7512.55017.41碳结1010.811

12、11139.9511.610.77510.310.6510.4750.32.703碳结1010.811111310.111.410.72510.410.7510.5750.152.703碳结129112.5134.512.413.212.812.512.9512.7250.0754碳结129112.5134.512.213.312.7512.612.9512.775-0.0254碳结从表中列出纵向壁厚差与减径量的关系如下:减径量与壁厚差的关系:1. D<12mm以内,则S<0.4mm2. D>12mm时,则S<0.6mm从图看出,减径机上减径是愈大,则经过的机架数愈多,纵向壁厚不均偏差大.另从减径机单机架变形量分析,12mm减径量基本相当于经过5个机架,头部与中间壁厚差基本产生4个阶梯.(这与理论相吻合)从第6个机架后及以后变形量造成的壁厚差很小.三. 纵向壁厚不均与D/S关系:(以上采集数据作图)D/S与壁厚差有如下关系:1. D/S<6,则S<0.7mm2. D/S>6,则S<0.4mm从实践数据看出,D/S愈小,则管子愈厚,纵向壁厚差相对较大些,但当采取合适的叠加比,可以将纵向