一、 引言
在钢中加入一种或几种一定数量的S、P、Pb、Ca、Se、Te等元素,可以改善钢的切削加工性能,用于制作受力较小,对尺寸和粗糙度要求严格的仪器仪表、手表零件、汽车、机床部件,以及对尺寸精度和粗糙度要求严格而对力学性能要求相对较低的标准件,如齿轮、轴、螺栓、阀门、衬套、销钉、管接头、弹簧座垫及机床丝杠、塑料成型模具、外科和牙科手术用具等。
但因为硫在钢中与锰形成MnS夹杂物,采用与低合金钢相同激发条件分析易切削钢时,Mn的校准曲线线性很差。因此,通过改变预燃时间、积分时间、积分电压等参数,改善了Mn的校准曲线线性,选择了适合易切削钢分析的实验条件,建立了火花直读光谱分析易切削钢的实验方法。
仪器配置
钢研纳克SparkCCD7000型火花直读光谱仪
SparkCCD 7000 全谱直读光谱仪可广泛应用于冶金、铸造、机械、钢铁和有色金属等行业,在汽车制造、航空航天、船舶、机电设备、工程机械、电子电工、教育、科研等领域的原料、零件、产品工艺研发方面都有广泛的应用。可用于 Fe、Al、Cu、Ni、Co、Mg、Ti、Zn、Pb、Sn、Mn 等金属及其合金的样品分析。
SparkCCD 7000全谱火花直读光谱仪采用高分辨率线阵CCD(Charge-coupled Device)作为检测器,实现全谱扫描。采用智能控制光室充气系统,仪器性能更 稳定,服务期限更长久。海量的谱线使分析不再受限,曲 线分段跳转同一元素不同谱线间实现无缝衔接,拓展分析 范围第三元素干扰校正使元素分析更加准确,可以在用户 现场任意增加材料基体和分析元素而无需增加硬件,维护 保养方便。能量、频率连续可调全数字固态光源,适应各 种不同材料;网口采集传输,速度快,通用性更强。
二、 结果与讨论
2.1 校准曲线
激发条件选定为充气时间10s,预燃时间35s,积分时间5s,激发频率500Hz,预燃电压0.5,积分电压0.15,氩气流量8L/min,方法中的各元素所用分析谱线及参比谱线、线性范围、线性相关系数列于表1中。
表1 各元素谱线选择及其线性相关系数
元素 | 分析线波长/nm | 参比线波长/nm | 线性范围/% | 线性相关系数,R2 |
C | 193.1 | 187.7 | 0.0098~0.39 | 0.99755 |
Si | 288.1 | 282.3 | 0.019~0.477 | 0.99901 |
Mn | 293.3 | 283.2 | 0.6~1.84 | 0.99559 |
P | 178.3 | 194.7 | 0.007~0.0778 | 0.99776 |
S | 180.7 | 194.7 | 0.097~0.38 | 0.99806 |
Cr | 267.7 | 258.2 | 0.017~0.568 | 0.99961 |
Ni | 231.6 | 223.3 | 0.0205~0.25 | 0.99964 |
Mo | 281.6 | 282.3 | 0.012~0.287 | 1.00000 |
Cu | 327.4 | 328.7 | 0.0056~0.25 | 0.99986 |
V | 311.0 | 308.4 | 0.002~0.0359 | 1.00000 |
Al | 396.1 | 392.2 | 0.002~0.032 | 0.99140 |
2.2精密度实验
按照2.1中选定的实验条件,在绘制的校准曲线下激发IMZ-122标样10点,所得测试结果列于表2中。
表2 稳定性测试结果(%,n=10)
元素 | 测试值 | 平均值 | 标准偏差 | RSD% |
C | 0.309,0.305,0.305,0.306,0.304,0.305,0.304,0.308,0.305,0.305 | 0.3056 | 0.00165 | 0.54 |
Si | 0.452,0.452,0.452,0.454,0.450,0.453,0.454,0.452,0.451,0.451 | 0.4521 | 0.00129 | 0.28 |
Mn | 1.309,1.316,1.298,1.311,1.295,1.309,1.306,1.314,1.308,1.302 | 1.3068 | 0.00671 | 0.51 |
P | 0.065,0.066,0.067,0.066,0.067,0.066,0.068,0.066,0.065,0.068 | 0.0664 | 0.00107 | 1.62 |
S | 0.168,0.175,0.172,0.175,0.174,0.171,0.174,0.176,0.174,0.171 | 0.173 | 0.00245 | 1.42 |
Cr | 0.178,0.179,0.179,0.179,0.179,0.179,0.180,0.179,0.179,0.179 | 0.179 | 0.00047 | 0.26 |
Ni | 0.240,0.239,0.236,0.238,0.235,0.238,0.237,0.238,0.237,0.238 | 0.2376 | 0.00143 | 0.60 |
Mo | 0.018,0.018,0.018,0.018,0.018,0.018,0.017,0.018,0.018,0.019 | 0.018 | 0.00047 | 2.62 |
Cu | 0.246,0.246,0.246,0.245,0.247,0.245,0.245,0.247,0.246,0.247 | 0.246 | 0.00082 | 0.33 |
V | 0.004,0.004,0.004,0.004,0.004,0.004,0.004,0.004,0.004,0.004 | 0.004 | / | / |
Al | 0.025,0.026,0.026,0.026,0.026,0.025,0.025,0.025,0.025,0.026 | 0.0255 | 0.00032 | 1.26 |
2.3正确度实验
按照2.1中选定的实验条件,在绘制的校准曲线下测试BS 66B、IARM 206A和IARM 29c三块标样,所得测试结果及标样参考值列于表3中。由表3可见,本方法测试结果与参考值一致性较好。
表3 易切削钢标样测试结果(%)
元素 | BS 66B | IARM 206A | IARM 29c | |||
测定值 | 参考值 | 测定值 | 参考值 | 测定值 | 参考值 | |
C | 0.429 | 0.418 | 0.068 | 0.068 | 0.182 | 0.180 |
Si | 0.020 | 0.020 | 0.017 | 0.019 | 0.289 | 0.280 |
Mn | 1.575 | 1.560 | 0.910 | 0.900 | 1.186 | 1.200 |
P | 0.018 | 0.018 | 0.070 | 0.069 | 0.008 | 0.011 |
S | 0.130 | 0.112 | 0.256 | 0.260 | 0.128 | 0.130 |
Cr | 0.093 | 0.093 | 0.041 | 0.041 | 0.075 | 0.076 |
Ni | 0.032 | 0.032 | 0.045 | 0.044 | 0.077 | 0.075 |
Mo | 0.023 | 0.019 | 0.010 | 0.012 | 0.014 | 0.016 |
Cu | 0.029 | 0.028 | 0.100 | 0.098 | 0.152 | 0.150 |
V | 0.0028 | 0.0014 | 0.0018 | 0.002 | 0.0028 | 0.003 |
Al | 0.0018 | 0.002 | 0.0021 | 0.003 | 0.0021 | 0.003 |
三、 实验结论
通过考察光谱预燃时间、积分时间、积分电压等激发参数与易切削钢中Mn的校准曲线线性相关系数的关系,找到了适合易切削钢分析的激发条件,建立了火花光谱分析易切削钢的实验方法,运用本方法分析易切削钢标样,测试结果与参考值一致性较好,各元素的相对标准偏差(RSD%)在0.26~2.62之间。该方法适用于易切削钢生产、使用单位快速分析及质量控制需要。
三、 钢研纳克其余直读光谱仪产品均可达到此效果
SparkCCD6500 全谱火花直读光谱仪
Labspark 1000 精密火花直读光谱仪