A good percentage of jobs in the UK are at risk of being automated away, and this includes all kinds of jobs including those which are the domain of social workers.
An article in The Guardian however makes the point that personal skills such as those which are required for social work could never be replaced by a machine. What makes this type of work the front as compared to other jobs is that it involves to handle sometimes confusing information, in ways that are hard to explain: the human ability which is called intuition. According to The Guardian and several experts in the field of computing and artificial intelligence, machines will likely never be able to accomplish this.
This makes social work, and other professions where unique human skills are required rather safe from being replaced by artificial intelligence any time soon.