【摘要】 研究了覆膜砂强度、发气性、热韧度的检测技术，并对部分覆膜砂产品进行检测和比较。认为：在０．５ＭＰａ压力下射制１１．２ｍｍ的试样，并在２１０℃芯盒中固化９０ｓ，然后用杠杆强度仪测量，这一强度检测方法比其它方法更为合理。在１０００℃加热砂样、冷却到１１０℃保温所产生的气体，测得的发气量较客观地表现了覆膜砂发气特征。通过测量覆膜砂变形－载荷曲线得到的热韧度，与砂芯的抗破断性有良好对应关系。更多还原

【Abstract】 The test technique about strength,gas evolution and hot toughness for precoating sand are investlgated,some pre-coating sands have been tested and compared.The strength test method,in which the sand sample of 11.2 mm thickness is prepared in a metal core-box heated to about 210℃ and filled by pre-coating sand under 0.5 MPa compressed air and hardened for 90s,and then tested with a levertype strength tester,is more reasonable than others.For the gas evolution test method,the sand samples heated to 1000℃ and cooled to 110℃,can show objectively the bas evolution characteristic of the type strength tester,Is more reasonable than others.For the gas evolution test method,the sand samcurve of the precoating sand and the resistance to fracture of cores更多还原