本发明提供一种超低碳低温用钢及其热处理工艺，由以下质量百分比的元素组成C：0.005‑0.01%；Ni：1.0‑4.5%；Mn：6.0‑12.0%；Al：1.0‑3.0%；Cu：0.5‑3.0%；P：≤0.005%；S：≤0.003%；N：0.005‑0.008%；O：0.0005‑0.002%；余量为Fe。本发明还进一步提供一种超低碳低温用钢的热处理工艺。本发明提供的一种超低碳低温用钢及其热处理工艺，采用利用残余奥氏体的TRIP效应和纳米析出相的析出强化，制备获得高强塑积超低碳节镍纳米析出强化低温钢，具有良好的强度和优异的塑性，并且具有良好的焊接性，成本较低，热处理工艺简易。

The present invention provides an ultra-low carbon low-temperature steel and its heat treatment process, which consist of the following elements by mass percentage: C: 0.005-0.01%; Ni: 1.0-4.5%; Mn: 6.0-12.0%; Al: 1.0-3.0% ; Cu: 0.5‑3.0%; P: ≤0.005%; S: ≤0.003%; N: 0.005‑0.008%; O: 0.0005‑0.002%; the balance is Fe. The present invention further provides a heat treatment process for ultra-low-carbon low-temperature steel. The invention provides an ultra-low-carbon low-temperature steel and its heat treatment process, which adopts the TRIP effect of retained austenite and the precipitation strengthening of nano-precipitated phases to prepare high-strength plastic product ultra-low-carbon nickel-saving nano-precipitation-strengthened low-temperature steel. It has good strength and excellent plasticity, and has good weldability, low cost, and simple heat treatment process.