厚规格汽车轮辐用钢的焊接性能

为了研究含Nb微合金控轧控冷厚规格汽车轮辐用钢的焊后组织、性能、冷裂纹敏感性及微合金元素对焊接性能的影响,采用理论计算评定试验钢的冷裂敏感性和淬硬倾向;利用直流氩弧工艺,模拟车轮厂焊接工艺参数,对钢板进行焊接.利用光学显微镜和电子显微镜研究试验钢板焊后接头的微观组织结构;并对接头的力学性能进行研究.试验结果表明,厚规格汽车轮辐钢的热影响区(HAZ)冷裂倾向小;微合金元素Nb的加入提高了焊接热影响区性能;焊接后各部位组织、性能未发生明显改变.可得出结论:厚规格汽车轮辐钢的焊接性能较好.

Welding Properties of Thick Spoke Steel for Automobile Wheels

To study the effects of microstructure of heat affected zone(HAZ) after welding,cold crack sensitivity and microalloying element on the welding properties of the Nb-microalloyed steel plates used for the specified thick spokes of car wheels,of which both the rolling and cooling processes were controlled,the cold crack sensitivity and hardening trend of the steel were evaluated by theoretical calculation.The steel plate was welded by DC argon arc process and the welding parameters were simulated just like what role they play in actuality.The microstructure of welded joints of steel plate were investigated by optical microscopy and EMS,as well as the mechanical properties by testers.The results showed that in the spoke plate the heat-affected zone(HAZ) tends to be small cold cracking and the Nb addition improves greatly the properties of HAZ with no obvious change in properties found in other zones after welding.It can thus be concluded that the thick spoke steel we developed has high weldability.