United Steel workers at Shield Alloy in Cambridge will vote this week on another contract proposal. The 69 workers have been in contract negotiations for over a month. According to Senior Vice President and General Manager, Hoy Franks, the contracts expired last Friday, but have been extended. Meanwhile, Franks says the company and employees were in intense negotiations over the weekend. During these contract disputes over the last month, workers have threatened to walk off the job. It’s reported union members are trying to negotiate better pay and benefits, but Franks would not confirm that report. The union is scheduled to meet again Wednesday.