双相钢有害金属间相测量结果不确定度的评定

Uncertainty Evaluation for Measurements of Detrimental Intermetallic Phase in Duplex Steels

双相不锈钢中存在的有害金属间相,对其韧性和耐蚀性的影响程度,可以采用ASTM A923-2014标准中三氯化铁腐蚀试验方法检测,其量值以腐蚀率表征。从腐蚀前后样品重量,以及样品的长度、宽度、厚度方面对影响测量结果的不确定度进行分析,计算和合成各不确定度分量,给出测量结果的扩展不确定度。结合扩展不确定度和其他因素的影响,对试验方法的合格指标设定上限。对超过该上限的试验样品进行适当的热处理,消除有害金属间相,最终提高产品的质量。结果表明:2205双相不锈钢有害金属间相测量结果为(3.9±1.4)mg/(dm^(2)·d),包含因子k=2。该试验方法合格指标的上限设定为8 mg/(dm^(2)·d)。

The influence of detrimental intermetallic phase in duplex steels on their toughness and corrosion resistance can be detected by the ASTM A923-2014 standard ferric chloride corrosion test method,with the value characterized by corrosion rate.This paper analyzes the uncertainties due to the weight,length,width and thickness of the samples before and after the corrosion.The uncertainty components were calculated and then combined to obtain the expanded uncertainty.Taking into account the expanded uncertainty and other factors,the upper limit of the acceptance criteria for the test method was chosen.In order to eliminate the detrimental intermetallic phase and finally improve the product quality,proper heat treatment is needed on the samples exceeding the upper limit.The results showed that the detrimental intermetallic phase of 2205 duplex stainless steel was(3.9±1.4)mg/(dm^(2)·d),with a coverage factor k=2.The upper limit of the acceptance criteria for this test method was chosen to be 8 mg/(dm^(2)·d).