{"title":"Transition fracture toughness testing with notched round bars (NRB)","authors":"Christopher D. Wilson, J. Landes","doi":"10.1520/STP14806S","DOIUrl":null,"url":null,"abstract":"The notched round bar (NRB) geometry was assessed for use with ASTM E 1921-97 Standard for Test Method for the Determination of Reference Temperature, T 0 , for Ferritic Steels in the Transition Range. Instead of precracking the NRB specimens, apparent fracture toughness using three different notch root radii was extrapolated to a zero radius to infer sharp crack fracture toughness. The reference temperature using A302B NRB specimens was determined to be -89°C, while A3028 C(T) specimens yield To of -87.3°C. In applying ASTM E 1921 to the NRB geometry, a simple scheme to remove notch root radius bias from apparent fracture toughness was developed. In addition, a size correction for converting NRB results to comparable IT-C(T) results was investigated.","PeriodicalId":8583,"journal":{"name":"ASTM special technical publications","volume":"2 1","pages":"305-317"},"PeriodicalIF":0.0000,"publicationDate":"2000-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ASTM special technical publications","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1520/STP14806S","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 3
Abstract
The notched round bar (NRB) geometry was assessed for use with ASTM E 1921-97 Standard for Test Method for the Determination of Reference Temperature, T 0 , for Ferritic Steels in the Transition Range. Instead of precracking the NRB specimens, apparent fracture toughness using three different notch root radii was extrapolated to a zero radius to infer sharp crack fracture toughness. The reference temperature using A302B NRB specimens was determined to be -89°C, while A3028 C(T) specimens yield To of -87.3°C. In applying ASTM E 1921 to the NRB geometry, a simple scheme to remove notch root radius bias from apparent fracture toughness was developed. In addition, a size correction for converting NRB results to comparable IT-C(T) results was investigated.
缺口圆棒(NRB)的几何形状根据ASTM E 1921-97在过渡范围内测定铁素体钢参考温度的试验方法t0标准进行了评估。采用三种不同的缺口根半径,将NRB试样的表观断裂韧性外推至零半径,从而推断出锐裂纹断裂韧性,而不是预裂。A302B NRB样品的参考温度为-89°C,而A3028 C(T)样品的屈服温度为-87.3°C。在将ASTM E 1921应用于NRB几何形状时,开发了一种从表观断裂韧性中去除缺口根半径偏差的简单方案。此外,研究了将NRB结果转换为可比较的IT-C(T)结果的大小校正。