T91 steel cold cracking tend to be larger, under certain conditions, import t91 alloy tube, prone to delayed cracking t91 alloy tube manufacturers, it must be tempered welded joints within 24 h after welding. T91 weld tissue state of lath martensite, tempered martensite after tempering can be changed, and its performance is superior than the lath martensite. When the tempering temperature is low, the tempering effect is not obvious, easy to aging and weld metal embrittlement; tempering temperature is too high (more than AC1 line), the joint may also austenitizing again and again in the subsequent cooling process hardened. At the same time t91, as described in the foregoing Shanghai t91 alloy tube, the tempering temperature should also be considered to determine the impact of the joint softening layer. Generally, T91 tempering temperature is 730 ~ 780 ℃ Guangdong Provincial Electricity Authority had done the first welding training center Φ42 mm × T91 trails 5mm tube butt welding procedure qualification. Preheating temperature taken to 200 ℃, after welding cooled to 150 ℃, tempering heat 1h, the tempering temperature is 750 ~ 780 ℃, insulation 1h, heating and cooling rate of less than 5 ℃ / min. After welding, visual inspection of the specimens, the fracture inspection, non-destructive testing, tensile and bending tests, the results are satisfactory, it also shows that the welding process is effective. t91 alloy tube 42X5 | Tonghua t91 | Katherine source of steel provided by source Pipe Co., Ltd. Liaocheng trillion. Liaocheng Katherine source Pipe Co., Ltd. (www.lczygg.com) strong, credible, Liaocheng in Shandong steel industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving Katherine source of innovative ideas will lead pipe and you work into the brilliant, for a better future!