Laborers work at a steel plant of Shandong Iron & Steel Group in Jinan, Shandong province, China, July 7, 2017. REUTERS/Stringer Register now for FREE unlimited access to Reuters.com Register Spillover-effect of property slump poses fresh risks to economy Steel demand, vital part of industrial engine, suffers blow Hit to construction ripples broadly, stings cement, appliances Credit constraints, property woes show no signs of easing soon BEIJING, Dec 19 (Reuters) – Debt problems at a major Chinese property developer have now spilled over into a vital artery of the nation’s industrial engine – the steel sector – and started to ripple through to other critical parts of the world’s second-largest…