本发明提供一种抗应力腐蚀高强度钢及其控轧控冷工艺，属于金属材料技术领域。该高强度钢化学成分质量百分比为：C≤0.06％，Si：0.20‑0.30％，Mn：1.5‑1.9％，P≤0.010％，S≤0.006％，Cr：0.20‑0.50％，Ni：0.20‑0.30％，Cu：0.20‑0.50％，Nb：0.03‑0.06％，N：0.004‑0.01％，其余为Fe，并且Nb和N的质量百分比满足：6≤Nb/N≤8。该高强度钢的控轧控冷工艺首先对连铸坯加热保温后进行第一阶段轧制，然后控制冷却：再开始第二阶段轧制和轧后冷却。本发明通过合理的合金成分设计和控轧控冷技术，改善钢的力学性能和抗应力腐蚀性能。按照本发明的化学成分和轧制工艺，可生产屈服强度大于550MPa级的钢，其内部纳米大量颗粒尺寸<10nm、分布均匀的Nb(C,N)析出相，使钢的力学性能及抗应力腐蚀性能显著优于普通成分和工艺生产的E550钢。

The invention provides stress-corrosion-resistant high-strength steel and a controlled rolling and controlled cooling technology thereof, and belongs to the technical field of metal materials. The high-strength steel comprises the following chemical components of, by mass percentage, less than or equal to 0.06% of C, 0.20-0.30% of Si, 1.5-1.9% of Mn, less than or equal to 0.010% of P, less than or equal to 0.006% of S, 0.20-0.50% of Cr, 0.20-0.30% of Ni, 0.20-0.50% of Cu, 0.03-0.06% of Nb, 0.004-0.01% of N and the balance Fe, wherein the mass percent of Nb and N meets the condition that Nb/N is greater than or equal to 6 and less than or equal to 8. The controlled rolling and controlled cooling technology for the high-strength steel comprises the steps of firstly, carrying out heating and heat preservation on a continuous casting blank, then carrying out first-stage rolling and controlled cooling; and then carrying out second-stage rolling and cooling after rolling. The high-strength steel and the controlled rolling and controlled cooling technology have the advantages that through reasonable alloy composition design and the controlled rolling and controlled cooling technology, the mechanical property and the stress corrosion resistance of the steel can be improved; and according to the chemical components and the rolling process, the steel with the yield strength greater than 550MPa can be produced, in the steel, the size of a large number of nano particles is less than 10nm, the Nb(C,N) precipitated phase is uniformly distributed, and therefore the mechanical property and the stress corrosion resistance of the steel can be obviously superior to the mechanical property and the stress corrosion resistance of E550 steel produced by common components and technologies.