The furface crazings are analyzed by metallographic test and electron prob for steel section,and it has been shown that the surface crazings is resulted from heating non regularly for steel section.

• 应用金相检验、电子探针等手段，对大型型钢表面龟裂进行了分析，结果表明：加热不当是造成型钢表面龟裂的主要原因。