Microstructural evolution during warm forging in the temperature range 800-650°C and the resulting mechanical properties are described for a Nb microalloyed grade 1541 steel. Compared with thermomechanical processing (TMP) forging at higher temperatures in the austenite range, the warm forging process lowers the TNR temperature and raises the Ar3 temperature. Warm forging produces significantly increased strength and impact toughness in the as forged + air cooled condition. The primary strengthening mechanisms in the warm forged plate are ferrite grain boundary strengthening, ferrite subgrain strengthening and pearlite lamellar strengthening. The increased Charpy impact energy is due to refined ferrite grain size. Delamination fracture ('splits') occurs in Charpy samples, which is thought to be associated with a {100} texture.
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机译：描述了Nb微合金级1541钢在800-650°C温度范围内温锻过程中的显微组织演变以及所得的机械性能。与奥氏体范围内较高温度下的热机械加工（TMP）锻造相比，温锻过程降低了T NR 温度，并提高了Ar 3 温度。在锻造+风冷条件下，热锻造可显着提高强度和冲击韧性。热锻板的主要强化机制是铁素体晶界强化，铁素体亚晶粒强化和珠光体层状强化。夏比冲击能的增加归因于精炼的铁素体晶粒尺寸。夏比样品中发生分层断裂（“裂口”），认为与{100}织构有关。
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