题目凡含碳量大于( )的铁碳合金,冷至727°C时均发生共析转变。A. 0.77%B. 0.0218%C. 4.3%D. 2.11%凡含碳量大于( )的铁碳合金,冷至727°C时均发生共析转变。A. 0.77%B. 0.0218%C. 4.3%D. 2.11%题目解答答案B. 0.0218%