钢的伸长率换算

1、钢的伸长率换算（碳钢和低合金钢）1. 适用范围 GB408092规定了不同标距之间断后伸长率的换算方法。此摘录只列出了标准中的部分方法。本标准只适用于室温下碳钢和低合金钢，其抗拉强度在300760N/mm2范围内的热轧、热轧和正火或退火，标距不超过25 ，或宽厚比不超过20的试样。当板状试样厚度小于4mm时，换算的伸长率必须经过供需双方商定。2. 符号及名称见下表1 表1符号名 称试样拉断后，标距伸长与原始标距的百分比r欲求标距的伸长率do圆形试样平行长度部分的原始直径Lo试样原始标距So试样平行长度部分的原始横截面积K拉伸试样的比例系数KLO/ 3. 基本公式 伸长率换算公式以Oliver公

2、式为基础，用于换算的基本公式为：r（Lo/ ）n·（ / Lor）n·（1）r（K/Kr）n·（2）式中：Sor欲求断后伸长率r所对应的试样横截面积；Lor欲求断后伸长率r所对应的试样原始标距；Kr欲求断后伸长率r所对应的试样比例系数；n常数，在此标准适用范围n=0.4以公式1或（2）为基础，制备出标准的全部表格和曲线图。此处列出三种转换方式。4. 模截面积相等的试样，从一个定标距到另一个定标距的伸长率换算 r（Lo/Lor）0.4·计算出常用定标距试样的（Lo/Lor）0.4值，称换算因子，列于表2，则ra·例：已知定标距200mm的试样的实

3、测伸长率为20，则换算出相同横截面积下，定标距100mm的伸长率值为1.320×20%=26.40%,见表2。附录F 钢的伸长率换算（碳钢和低合金钢）表2 不同定标距之间的换算因子a（面积相同）由此换算换算到下列定标距的换算因子a50mm80mm100mm200mm50mm1.0000.8290.7580.57480mm1.2071.0000.9150.693100mm1.3201.0931.0000.758200mm1.7411.4431.3201.0001. 从比例标距到定标距的伸长率换算 例：1.标距5.65 的伸长率为20，换算成宽为25mm，厚为6mm，标距为50mm试样的

4、伸长率，根据表3换算为20×1.139=22.78%.2.40mm×10mm，标距200mm的试样，伸长率为25，换算成标距为5.65 的伸长率。根据表3换算为25×1/0.796=31.41%。六、横截面积不等的试样，从一个定标距到另一个定标距的伸长率换算可利用表3分两步进行换算，首先将已知定标距的伸长率换算到比例伸长率，如5.65 ，再换算到欲求标距的伸长率。例：40mm×15mm、标距200mm的试样伸长率为24，换算成30mm×10mm试样，标距为200mm的伸长率。首先根据表3换算到5.65 标距的伸长率即24×1/0.86

5、327.81;再换算到30mm×10mm，200mm标距的伸长率，即27.81×0.752=20.91%。附录F 钢的伸长率换算（碳钢和低合金钢）（续）表3 由标距长率5.65 换算成不同定标距的换算因子试样横截面积由比例标距5.65 到下定标距的换算因子mm2200mm 100mm80mm50mm510152025303540455055607080901001101201301401501601701801902002102202302402502602702800.3310.3810.4130.4370.4570.4740.4890.5020.5140.5250.53

6、50.5450.5620.5770.5910.6030.6150.6260.6360.6450.6540.6630.6710.6790.6860.6930.7000.7060.7130.7190.7250.7300.7360.7410.4370.5020.5450.5770.6030.6260.6450.6630.6790.6930.7060.7190.7410.7610.7800.7960.8120.8260.8390.8520.8630.8750.8850.8960.9050.9150.9240.9320.9410.9490.9560.9640.9710.9780.4780.5490.59

7、60.6310.6600.6840.7060.7250.7420.7580.7720.7860.8110.8330.8520.8710.8870.9030.9170.9310.9440.9560.9680.9790.9901.0001.0101.0191.0281.0371.0461.0541.0621.0700.5770.6630.7190.7610.7960.8260.8520.8750.8960.9150.9320.9490.9781.0051.0291.0511.0711.0901.1071.1241.1391.1541.1681.1821.1951.2071.2191.2301.24

8、11.2521.2621.2721.2811.291附录F 钢的伸长率换算（碳钢和低合金钢）（续）表3 由标距长率5.65 换算成不同定标距的换算因子(续)试样横截面积由比例标距5.65 到下定标距的换算因子mm2200mm 100mm80mm50mm2903003103203303403503603703803904004104204304404504604704804905005506006507007508008509009501 0001 0501 1001 1501 2000.7470.7520.7570.7610.7660.7710.7750.7800.7840.7880.7920

9、.7960.8000.8040.8080.8120.8150.8190.8220.8260.8290.8330.8490.8630.8770.8910.9030.9150.9260.9360.9470.9560.9660.9750.9830.9920.9850.9920.9981.0050.0110.0171.0231.0291.0341.0401.0451.0511.0561.0611.0661.0711.0761.0801.0851.0901.0941.0991.1201.1391.1581.1751.1911.2071.2221.2361.2491.2621.2741.2861.2981

10、.3091.0771.0841.0921.0991.1051.1121.1181.1251.1311.1371.1431.1491.1541.1601.1651.1711.1761.1811.1861.1911.1961.2011.2241.2461.2661.2851.3031.3201.3361.3511.3661.3801.3931.4061.4191.4311.3001.3091.3171.3261.3341.3421.3501.3571.3651.3721.3761.3861.3931.4001.4061.4131.4191.4261.4321.4381.4441.4501.4771

11、.5031.5281.5501.5721.5921.6121.6301.6481.6651.6811.6971.7121.707附录F 钢的伸长率换算（碳钢和低合金钢）（完）表3 由标距长率5.65 换算成不同定标距的换算因子(完)试样横截面积由比例标距5.65 到下定标距的换算因子mm2200mm 100mm80mm50mm1 2501 3001 350 1 4001 4501 5001 5501 6001 6501 7001 7501 8001 8501 900 1 9502 0002 0502 1002 1502 2002 2502 3002 3502 4002 4502 5002 55

12、02 6002 6502 7002 7502 8002 8502 9002 9503 0001.0001.0081.0161.0231.0301.0371.0441.0511.0571.0631.0701.0761.0821.0871.0931.0991.1041.1091.1151.1201.1251.1301.1351.1391.1441.1491.1531.1581.1621.1671.1711.1751.1791.1831.1871.1911.3201.3301.3401.3501.3591.3691.3781.3861.3951.4031.4111.4191.4271.4351.4421.4501.4571.4641.4711.4771.4841.4911.4971.5031.5101.5161.5221.5281.5331.5391.5451.5501.5561.5611.5671.5721.4431.4541.4651.4761.4861.4961.5061.5161.5251.5341.5431.5521.5601.5691.5771.5851.5931.6001.6081.6151.6231.6301.6371.6441.6511.6571.6641.6701.6771.6831.6891.