four-point

Heat treatment and pre-strain, tensile test of the material and four point bending test have been carried to obtain the mechanical property of the undegraded and degraded material at low temperature.

本文首先通过分析复合脆化处理实验、拉伸实验和缺口试件四点弯曲实验的结果，考察比钢在脆化处理前后的室温和低温学性能。