Fig. 2. Work times determined with the interval test are significantly less than that of cor- relating work times determined with the B scale mold hard- ness gauge.
图2. 与间隔测试确 定的可使用时间明 显小于B标尺硬度 计测定的可使用时 间。
On the Shop Floor
Te advantage to the gauge test is its simplicity, and it could still be used on the shop floor, but with different indicator readings. Metalcasting facilities may perform the interval test once for each type of binder used to lay the foundation for work times and adjust the indicator amount from the B scale hardness gauge accordingly. Metalcasters also should remember the following to
ensure the proper production of molds and cores: • Keep work time as short as possible for better productivity. • Size the sand mixer to the size of the mold or core. • Slow down the cure time using slower catalysis if neces- sary for a longer work time.
• A B scale mold hardness of 60 is not a good work time measure. Work time is much less on the B scale gauge, depending on the binder.
• Furan nobake binders have a short work time compared to the strip time (the time it takes to fill the corebox and then cure before the core is ready to be removed). Phenolic urethane nobake and ester-cured phenolic binders have work times of about half the strip time. To receive this digital magazine in the future, go to
www.globalcastingmagazine.com.
用，但辅以不同的指标读数。铸造厂可以为每种类型的 粘合剂可使用时间完成一次用于奠定基础的时间间隔测 试，并相应调整B级硬度计的指标量。
铸造工人也应记住以下几点，以确保砂模和型芯的正 常生产：
•保持可使用时间尽可能短，以提高生产率。 •按砂模或芯的大小确定混砂量。
•如果需要一个较长的可使用时间，使用速度较慢的 催化剂减缓固化时间。
•60的AB级的模型硬度计，不是一个很好的可使用时 间的测量工具。可使用时间非常少的靠B级模型硬度 计，取决于粘合剂。
•相比的脱模时间，呋喃自硬粘结剂可使用时间很短 （时间花费在填充芯盒，然后固化，在芯子准备被移 除之前）。
•酚醛尿烷自硬粘结剂和酯固化酚醛粘结剂的可使用 时间是脱模时间一半左右。
访问
www.globalcastingmagazine.com可拷贝2012年AFS 砂型铸造会议全部报告。
Fig. 3. Shown is a comparison of the percentage tensile loss in the interval versus the B scale mold hardness gauge measurement for furan nobake binder.
图3. 显示的是 使用喃自硬粘结 剂，B标尺硬度计 测量和间隔测试 的抗拉强度损失 百分比的比较。
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FOUNDRY-PLANET.COM | MODERN CASTING | CHINA FOUNDRY ASSOCIATION February 2013
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