Martensite is an important phase for the strengthening of interstitial-free (IF) steel. The as-received sample is soaked in the austenitic temperature domain at 930 °C for 5 minutes, followed by water quenching in a Gleeble 3800® thermo-mechanical simulator. The outcome shows a dramatic increase in strength by lath martensite and massive ferrite. Hot deformation is also a part of the comparative study. The as-received sample is processed in 0.5 compressive strain at the rate 0.01/s in the same austenitic temperature domain, followed by water quenching. Dynamic recrystallization has not been observed. Instead, plastic deformation in austenite leads to grain boundary nucleation of diffusional ferrite, inhibiting nucleation and growth of massive ferrite in a triplex phase mixture of lath martensite. The austenite to martensite transformation follows Kurdjumov–Sachs (K–S) orientation relationships. The calculated variants based on the K–S orientation relationships between parent and product phase designate that the transformation of differently oriented martensite can originate under constraints from deformed austenite. Thus, the strength-ductility combination is verified with martensite obtained under two different austenite conditions.

马氏体是强化无间隙（IF）钢的重要阶段。将收到的样品在930°C的奥氏体温度域中浸泡5分钟，然后在Gleeble3800®热机械模拟器中进行水淬。结果表明板条马氏体和块状铁素体的强度显着提高。热变形也是比较研究的一部分。在相同的奥氏体温度范围内，以0.5的压缩应变以0.01 / s的速度处理接收到的样品，然后进行水淬。尚未观察到动态重结晶。相反，奥氏体中的塑性变形会导致扩散铁素体的晶界形核，从而抑制板条马氏体三相相混合物中块状铁素体的形核和生长。奥氏体到马氏体的转变遵循Kurdjumov-Sachs（KS）取向关系。根据母相和产物相之间的K-S取向关系计算得出的变体表明，取向不同的马氏体的转变可以在变形奥氏体的约束下产生。因此，利用在两种不同奥氏体条件下获得的马氏体来验证强度-延性组合。