钎焊-热轧法制备高速公路不锈钢复合护栏

针对当前高速公路热镀锌护栏存在的主要问题,提出采用不锈钢/碳钢复合板作为新型高速公路护栏材料.研究了钎焊-热轧法制备不锈钢复合护栏的工艺,技术路线为通过炉中钎焊实现不锈钢/碳钢的初结合,对钎焊复合板进行热轧进一步提高结合强度.研究结果表明:采用自制的Ag质量分数为15%的钎料可以实现不锈钢/碳钢有效的钎焊结合,钎焊温度720~730℃,钎焊时间3~4 min是较理想的工艺条件.对钎焊复合板热轧可以显著提高不锈钢/钎料界面的结合强度,压下率低于30%时,轧后钎料层未出现断裂、分层.热轧后,不锈钢复合护栏剪切强度可达338.4 MPa.

Preparation of Stainless Steel Clad Guardrails for Superhighway by Brazing/Hot-Rolling Process

Aiming at the main problems of the hot-dip galvanized guardrails for superhighway, the carbon steel plate with stainless steel cladding was recommended as a new guardrail material. The preparation of stainless steel cladding guardrail by brazing/hot-rolling process was proposed, the stainless steel sheet and carbon steel plate are bonded together first by brazing in furnace, then the bonding strength is improved by hot-rolling. The results showed that an effective braze welding can be obtained by using a silver-base soldering flux developed, in which the Ag content is 15wt.%. The following parameters are regarded as ideal: the brazing temperature is 720-730°C, at which the time needed is 3-4 min. The soldering flux layer shows good plasticity in hot-rolling process. When the percent reduction is less than 30%, no cracks and lamination are found in the soldering flux layer after hot-rolling, with the shear strength of stainless steel clad guardrails up to 338.4 MPa.