材料期刊网

Nb、Ti是管线钢中常用的合金元素。本文主要通过热处理和喷碳处理等手段研究了合金元素Nb、Ti的含量及加热制度对再加热奥氏体晶粒长大的影响。试验结果表明，试验钢在再加热过程中，奥氏体晶粒尺寸随加热温度的升高而增大；在常规含铌钢中，为获得较小的加热态奥氏体晶粒，钛含量应控制在一定范围内（约0.010%～0.015％），钛含量过高或过低都对晶粒细化有不利影响。此外，在钛含量相同的情况下，高铌钢奥氏体晶粒长大明显，高铌钢的最佳钛含量范围也与常规含铌钢的最佳钛含量不同。

Nb and Ti are the most common microalloying elements in pipeline steel. The effects of the microalloying elements Nb and Ti in Nb-Ti microalloyed steel and the reheating schedule on the austenite grain growth were investigated using heat treatment and vacuum carburizing treatment. The results showed that during reheating process, the austenite grain size in tested steel increased with an increase in the reheating temperature. In normal niobium-containing steel, titanium content should be controlled in a certain range (approximately 0.010%~0.015%), to obtain small reheated austenite grain. Moreover, with the same titanium content, the austenite grain in a steel with high niobium content grows obviously, and the steel with high niobium content has a different optimum titanium content range from that of the steel with normal titanium content.