回火温度对低合金高强度无缝钢管组织和性能的影响

Effect of Tempering Temperature on Microstructure and Properties of Low-alloy High-strength Seamless Steel Tube

研究了淬火后回火温度对一种新型低合金高强度无缝钢管的组织和力学性能的影响。结果表明:试验钢管经930℃淬火和0~750℃回火后,抗拉强度为959~1375 MPa;200和700℃回火后冲击吸收能量最高,400及500℃回火后冲击吸收能量最低,并出现了回火马氏体脆性。200℃回火后抗拉强度为1375 MPa,断后伸长率为13.8%,断面收缩率为60.9%,冲击吸收能量为63.4 J。700℃回火后抗拉强度为981 MPa,断后伸长率为18.8%,断面收缩率为51%,冲击吸收能量为68.7 J。200℃回火组织为回火马氏体和少量残留奥氏体,700℃回火组织为回火索氏体。

Influence of tempering temperature after quenching on the microstructure and mechanical properties of a newly developed low-alloy high-strength seamless steel tube was studied.The results showed that after quenching from 930℃and tempering at temperature range of 0 to 750℃,the test steel tube possessed tensile strength of 959 to 1375 MPa.The impact absorption energy reached the highest after tempering at 200 and 700℃,the lowest after tempering at 400 and 500℃,and the tempered martensite brittleness appeared.After being tempered at 200℃,the tensile strength was 1375 MPa,the elongation was 13.8%,the reduction of area was 60.9%and the impact absorption energy was 63.4 J.After being tempered at 700℃,the tensile strength was 981 MPa,the elongation was 18.8%,the reduction of area was 51%and the impact absorption energy was 68.7 J.The microstructure was tempered martensite and a small amount of retained austenite after being tempered at 200℃,and tempered sorbate after being tempered at 700℃.