(1)牌号和化学成分见表3-6、表3-7。(2)力学性能见表3—8。(3)用途见表3-9。表3—6优质碳素结构钢的牌号和化学成分序号统一数字代号牌号化学成分(质量分数)(%)CSiMnCrMCu≤1U2008008FO.05~O.11≤0.030.25~0.500.10O.300.252U20l0010FO.07~O.13≤O.07O.25~O.50O.150.300.253U2015015F0.12~O.18≤O.070.25~O.500.250.300.254U20082080.05~O.11O.17~O.37O.35~O.65O.10O.30O.255U20102lO0.07~O.130.17~O.370.35~0.650.15O.30O.256U2015215O.12~0.180.17~O.37O.35~0.65O.25O.30O.257U2020220O.17~0.230.17~0.370.35~0.65O.25O.30O.258U2025225O.22~0.290.17~O.37O.50~O.80O.25O.300.259U2030230O.27~O.34O.17~O.37O.50~O.800.25O.300.2510U2035235O.32~0.39O.17~O.37O.50~O.B00.25O.300.2511U20402400.37~O.440.17~O.37O.50~O.80O.25O.30O.2512U2045245O.42_O.50O.17~O.370.50~0.800.25O.300.2513U20502500.47~0.550.17~O.370.50~0.800.25O.30O.2514U2055255O.52~0.60O.17~O.37O.50~0.80O.250.30O.2515U20602600.57~O.650.17~O.370.50~O.80O.25O.300.2516U2065265O.62~0.700.17~0.37O.50~O.80O.25O.30O.2517U2070270O.67~0.750.17~0.37O.50~O.800.25O.30O.2518U2075275O.72~0.800.17~O.370.50~0.800.25O.30O.2519U2080280O.77~0.85O.17~0.37O.50~O.800.25O.300.2520U2085285O.82~0.90O.17~0.370.50~O.80O.25O.30O.2521U2115215№O.12~O.18O.17~O.37O.70~1.00O.25O.300.2522U2120220Mn0.17~O.23O.17~O.37O.70~1.00O.250.30O.2523U2125225MnO.22~O.290.17~0.37O.70~1.00O.25O.30O.2524U2130230Mn0.27~O.34O.17~0.370.70~1.00O.25O.300.2525U2135235MnO.32~O.39O.17~O.37O.70~1.000.25O.30O.2526U2140240MnO.37~0.44O.17~0.37O.70~1.000.250.30O.2527U2145245Mn0.42~0.500.17~O.370.70~1.00O.25O.30O.2528U2150250MnO.48~0.56O.17~O.37O.70~1.000.250.300.2529U2160260Mn0.57~0.65O.17~O.370.70~1.000.250.300.2530U2165265Mn0.62~0.700.17~O.37O.90~1.20O.250.300.253lU2170270Mn0.67~O.750.17~0.370.90~1.20O.25O.30O.25注:1.表中所列牌号为优质钢。如果是高级优质钢,在牌号后面加“A”(统一数字代号最后一位数字改为“3”);如果是特级优质钢,在牌号后面加“E’’(统一数字代号最后一-位数字改为“6”);对于沸腾钢,牌号后面为“F”(统一数字代号最后一位数字为“0”);对于半镇静钢,牌号后面为“b”(统一数字代号最后一位数字为“1”)。2.使用废钢冶炼的钢允许含铜量不大于0.30%。3.热压力加工用钢的铜含量应不大于0.20%。4.铅浴淬火(派登脱)钢丝用的35.85钢的锰含量为0.30%~0.60%;铬含量不大于0.10%,镍含量不大于O.15%,铜含量不大于0.20%;硫、磷含量应符合钢丝标准要求。5.08钢用铝脱氧冶炼镇静钢,锰含量下限为0.25%,硅含量不大于0.03%,铝含量为0.02%一0.07%。此时钢的牌号为08A1。6.冷冲压用沸腾钢含硅量不大于0.03%。7.氧气转炉冶炼的钢其含氮量应不大于0.008%。供方能保证合格时,可不做分析。8.经供需双方协议,08~25钢可供应硅含量不大于0.17%的半镇静钢,其牌号为08b~25b。9.上述各成分含量皆指质量分数。表3-7优质碳素结构钢的硫、磷含量(质量分数)组别PS(%)≤优质钢0.0350.035高级优质钢0.0300.030特级优质钢0.025O.020表3-8优质碳素结构钢的力学性能牌号试样毛坯尺寸/mm推荐热处理/℃力学性能钢材交货状态硬度HBSl0/300≤正火淬火回火ób/MPaós/MPaδ5(%)Ψ(%)AKu2/J≥未热处理钢退火钢08F25930295175356013l10F25930315185335513715F25920355205295514308259303251953360131IO篮9303352053l551371525920375225275514320259104lO24525551562525900870600450275235071170302588086060049029521506317935258708506005303152045551974025860840...