Abstract��The W18Cr4V needle valve was analyzed by chemical composition�� metallurgical structure observation and energy spectrum. The formation cause of point-like defect on surface was analyzed and discussed. It was found that the surface defect of needle valve was not due to the raw materials or metallurgical defects such as hairline and air hole�� while it was corrosive defect formed in heat treatment salt bath medium containing moisture.
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�ο��ģ���ȫ��. W18Cr4V�뷧�����״ȱ�ݷ���[J]. �й������ڿ���, 2016, 34(1): 25-28.
HE Kai-wen��ZHANG Quan-xin. Analysis of point-like defect on surface of W18Cr4V needle valve. Chinese Journal of Iron and Steel, 2016, 34(1): 25-28.
2016, Vol. 34 
